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The machining characteristics of A286 stainless steel material for various machining operations are comprehensively reviewed in this paper. As compared to austenitic stainless steels, this steel offers a good balance between oxidation resistance and high temperature strength. Because of these superior properties, the alloy is being used in jet engines, superchargers, fasteners, as well as applications that required high temperature including turbine wheels, structures, after burner components and casings. However, due to their low hardness, they restrict their employment in areas including wear from abrasives and make it difficult to achieving efficient machining processes. This review focuses on analyzing the machining aspects of A286 stainless steel in turning, milling, and drilling operations. A number of significant elements are looked at, including cutting parameters like the level of cut, the rate of feed, and speed as well as tooling materials, surface polish, and tool wear. The aim is to provide valuable insights into optimizing machining processes for A286 stainless steel, offering practical guidance to manufacturers and researchers for improving productivity and reducing costs. Furthermore, the review identifies and discusses challenges specific to machining A286 stainless steel and explores potential solutions to address issues such as work hardening, heat generation, and tool wear. The paper concludes by suggesting future research directions, including the investigation of advanced machining techniques, coating and surface modification of tool materials, sustainable machining approaches, and multi-objective optimization of machining processes. Overall, this review serves as a comprehensive resource for understanding the machining characteristics of A286 stainless steel, enabling the development of effective machining strategies for this material. [ABSTRACT FROM AUTHOR]

In the present investigation, the 304 austenitic stainless steel has been strained up to 0% and 15% reduction in thickness, and analysis has been done with the help of X-ray diffraction (XRD) and microstructure. In 304 austenitic stainless steel (ASS) the microstructure through optical as well as scanning electron microscope 9SEM) has been studied at various thermal aging temperatures with and without strained at 0% and 15%. X-Ray diffraction results show that as stacking fault energy is greater with an increase in straining from 0% to 15%, 304 ASS seems to be deformed more quickly, resulting in a fast conversion to strain induced martensite from austenite. The XRD data also show that a higher percentage of martensite was produced. Microstructure results indicated that due to straining and high temperature heat treatment of 950°C-1000°C, small refined grains of new austenite formed which became the main reason for high strength and ductility. However other side shows that at a common temperature of 850°C-900°C, according to a microstructural study, the martensitic areas are an ideal source for increasing sensitization. [ABSTRACT FROM AUTHOR]

The purpose of this work is to provide the findings of an extensive investigation on the impact of technical factors in the Tungsten Inert Gas (TIG) welding process on the improvement of the durability of metal weld joints. It is essential to ensure the endurance of weld joints in order to maintain the structural integrity and functionality of welded components in a variety of different industries. This study studies the factors that contribute to the longevity of welded joints, including the influence of filler materials and post-weld treatments, as well as the impacts of welding parameters such as current, voltage, and the shielding gas flow rate. The findings of the experiments shed light on the connections that exist between these factors and the mechanical characteristics of welded joints. The results provide a contribution to the optimization of TIG welding settings for the purpose of generating lasting weld connections and provide suggestions for practical applications in the automotive, aerospace, and structural engineering industries. In accordance with Taguchi L9 orthogonal array (OA) theory, experiments were carried out on a 3 mm thick plate of austenitic stainless steel AISI 316L utilizing TIG welding equipment. ER316L served as the filler material. The data were analyzed using the signal to noise ratio (S/N ratio) and analysis of variance. The optimization of the tensile strength response was shown to be most influenced by the shielding gas flow rate. The parameters of current 90 A, voltage 15.5 V, and gas flow rate 35 ft³/h as well as current 100 A, voltage 15 V, and gas flow rate 35 ft³/h resulted in the greatest tensile strength. The most crucial element for the optimization of maximum flexural strength and hardness responses was revealed to be arc current. A parametric combination of current 90 A, voltage 14.5 V, and gas flow rate 25 ft³/h resulted in the hardest material. The parametric combination of current 90 A, voltage 14.5 V, and gas flow rate 25 ft³/h resulted in the greatest flexural strength (bending). [ABSTRACT FROM AUTHOR]

AISI-410-3Mo-3Ni is martensitic stainless steel that has been applied in various industrial equipment, such as oil and gas pipelines, turbine blades, and cooling tower systems, due to its combination of strength, toughness, and excellent corrosion resistance. Corrosion is one of the problems in oil and gas application due to its deteriorative effect on the material, leading to failure fracture. Chitosan was chosen as an eco-friendly inhibitor due to its fascinating properties where the higher molecular weight of chitosan can contribute to extensive coverage of the metal surface. This work aims to study the potential of chitosan as a sustainable natural-based corrosion inhibitor for annealed AISI 410-3Mo-3Ni in a 3.5% NaCl solution. The corrosion activity is observed using electrochemical measurements and morphology observation. Furthermore, the variations of chitosan are 500 and 1000 ppm using annealed samples with the temperature of 800, 850, and 900°C. Test results indicate that chitosan has good inhibition properties, whereas the sample with untreatment and 500 ppm of chitosan has the highest free corrosion potential of-317.775 mV vs SCE. However, Tafel polarization shows all the samples with 1000 ppm chitosan have a lower corrosion rate than samples with 500 ppm chitosan. Surface observation confirms the adsorption of chitosan and corrosion phenomena (pitting and uniform corrosion) in all the samples. [ABSTRACT FROM AUTHOR]

Austenitic Stainless Steel 304 is an extremely important commercial alloy due to its excellent corrosion resistance, high strength, good ductility and toughness. The material used in the work is Austenitic Stainless Steel 304 sheets of 0.5 mm thickness. The nominal chemical composition for each element in the specimen material is C 0.08%, Cr 18-20%, Ni 8.0-10.5%, Mn 2.0%, Si 0.75%,S 0.03%, P 0.045%, N 0.10%. The experiments were designed to assess the mechanical characteristics of Rsistance spot welds by performing hardness test and to optimize the welding parameters. These welding Parameters are welding current, pressure or electrode forcea and weld cycles. The non-linear behavior, if it exists, among the process parameters can only be studied if more than two levels of the parameters are used. Therefore, each parameter was analyzed at three levels. The conclusions drawn from the present work are that an increase in weld current and electrode force increases the nugget hardness with a consequent increase in the tensile strength. However, with the increase in the number of welding cycles, the nugget hardness first decreases and then increases when the number of weld cycles goes beyond 8. The effect of number of weld cycles on the tensile strength of the nugget is quite different from that on nugget hardness. With the increase in no. of weld cycles, the tensile strength first increases and then decreases sharply. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are a type of stainless steel that supplements the iron base with considerable levels of nitrogen, manganese, molybdenum, and chromium. In general, these steel lacks with poor hardness and resistance to wear. In order to promote hardness, wear resistance, these steels are subjected to case hardening process. Various case hardening techniques like carburizing, carbo-nitriding, cyaniding, nitridng techniques are available to enhance the wear resistance. Among which gas nitriding process is carried out for this research work. At constant load, the wear behaviors of AISI 304 and AISI 904 L stainless steel were investigated. Gas nitriding were carried out on AISI 304 and AISI 904L stainless steel. The wear behavior, surface hardness and case depth were thoroughly evaluated. The samples were prepared to10 mm diameter and length of 40 mm respectively and. The specimens were gas nitrided by passing 100 ml/min of ammonia gas to flow through the quartz tube, at 610°C. The processes were carried out to 6 hours, 18 hours, and 24 hours. On the other side, for comparison of results, an untreated specimen was kept aside. The wear characteristics were analyzed by pin-on-disc tribometer and the hardness of the specimens were measured through Vickers hardness machine. The microstructures of the samples were compared through scanning electron microscopy analysis and the best wear resistant samples were chosen for the required application. [ABSTRACT FROM AUTHOR]

Austenitic stainless steel is well known for its superior corrosion resistance, but they lack hardness. To overcome the above problem, several case hardening processes such as nitride, carburizing, carbonitriding, nitrocarburizing and cyaniding were adopted. Chosen for this research work, AISI 310 were taken for the following dimension 8mm diameter and42 mm length respectively. The specimens were undergone with aqueous soluted salt bath treatment for 70 minutes, 130 minutes, and 190 minutes at 570°C and were named as SBT 1, SBT 2, SBT 3 respectively. An untreated sample is used for comparing the results with the processed ones. The specimens were subjected to wear test using pin-on disc tribometer. A load of 20N was applied against a disc rotation at a speed of 1000 rpm. Measurements of hardness were done using a Rockwell hardness machine. All the specimens were undergone with Scanning Electron Microscope (SEM) for microstructural studies. A comparison study is made between all the samples and the better wear resistant sample is chosen for the required application. [ABSTRACT FROM AUTHOR]

The advanced high strength steel(austenitic stainless steel) exhibits outstanding mechanical properties due to the occurrence of two deformation mechanisms: dislocations glide (slip) and phase transformation (austenitic fcc phase to strain induced α martensite (bcc)phase). Both mechanisms have strong dependence on strain and strain paths. In present study, the major strain is more in case of uniaxial drawing (US) followed by biaxial stretching (BS) and plane strain(PS) which is in line with martensite volume fraction. In this paper surface strains were measured by using digital image correlation (DIC) technique and microstructual studies (phase fraction and texture) were carried out at various strain level (low strain (60% deformation), intermediate strain (80% deformation) and high strain (upto failure)) and strain paths using electron back scattered diffraction (EBSD) technique. [ABSTRACT FROM AUTHOR]

Ferritic stainless steel is less weldable than austenitic stainless steel and has drawn greater attention due to their cost effectiveness and better corrosion resistance. AISI 430 ferritic stainless steel is widely used due to its corrosion resistance property. Presence of chromium forms a passive layer, which resist the attention of atmospheric oxygen. Most of the metallurgical phase present in ferritic stainless steel is ferrite with alloying element aluminum and molybdenum. A brief study is carried out to evaluate the corrosion behavior of 430 ferritic stainless steel in acidic, basic and aqua solution. The results revels that, the effect of corrosive environment is different in different solutions as the weight loss pattern is different. Corrosion rate decreases with time because of oxide layer formation on the specimens. [ABSTRACT FROM AUTHOR]

Welding using gas tungsten arc (GTAW) is a common method for combining metals that are different or similar in composition. In terms of sound welds, the technique has various benefits. However, the heat input and process speed are still major problems that may be compensated for by sound quality of the resultant welding. The GTAW technique is employed in a variety of industrial applications because of the above-mentioned benefits, including overlay welding, root joint welding, and fill pass welding. It has been discussed in this article how the GTAW technique may be used to fuse dissimilar metals, root joints, and fill pass welding, among other things. The GTAW procedure is used to create dissimilar welds from 15CDV6 stainless steel and SS321 for the study's buttering deposits. Welding chemistry and microstructure are affected by the GTAW process's metallurgical variables. The tensile strength of the GTAW weldment joint is 620, according to the findings of the study. The fractography showed that the GTA weldment had a greater ductility, with an elongation of 26%. [ABSTRACT FROM AUTHOR]

Several recent studies have revealed, that the structural resistance of stainless steel members under compressive loading determined in accordance with the current European standard does not satisfy sufficiently small level of failure probability. It has been observed, that currently utilized flexural buckling curves overestimate the ultimate structural resistance of stainless steel members of certain material grades and cross-sectional geometries. Not negligible differences have been achieved between the estimations based on standards and experimental data, mainly for specific range of member slenderness values. Compared to carbon steel, stainless steel has higher ductility, and in order to properly describe the stress-strain material behavior, higher numbers of material parameters are required. The subject of this article is to closely investigate the influence of these parameters (material, cross-sectional geometry and also parameters to describe global imperfection) on the ultimate resistance of the members exposed to flexural buckling. Previously validated numerical finite element models of the circular hollow cross-section (CHS) members are created in ANSYS Classic software utilizing parametric APDL macros. Statistical characteristics of all the input parameters along with their mutual correlations are obtained from recent comprehensive statistical research study. The sensitivity analysis is conducted for three different material grades of stainless steel: Austenitic, grade 1.4307, Ferritic 1.4003 and Duplex 1.4462, and for various values of the member slenderness. The purpose of the numerical models is to determine the ultimate limit state of the CHS members exposed to compressive loading utilizing geometrically and materially nonlinear analyses with initial geometrical imperfections. Influence of each input parameter on the model output (ultimate resistance) is investigated, and the results are well documented and discussed. The sensitivity analysis reveals, which of these parameters have the highest influence on the structural resistance, hence are the most significant for the monitored output, considering their statistical distribution and value range. Study also provides data for the subsequent optimization process of the flexural buckling curves, which can be feasibly conducted utilizing the first order reliability method. [ABSTRACT FROM AUTHOR]

The evolution of the grain boundary assemblies in an austenitic stainless steel during grain growth following primary recrystallization was studied at temperatures of 1000 °C and 1100 °C. An increase in annealing temperature promoted the grain growth at early annealing, whereas the grain size evolved during long time annealing was almost the same at both temperatures. The grain size increased above 200 µm after annealing for 10 hours irrespective of annealing temperature. The fraction of Σ3 CSL boundaries associated with annealing twins increased with an increase in the grain size. The grain growth was accompanied by an effective interruption of ordinary grain boundaries by special ones, i.e., Σ3 CSL boundaries. The discontinuity of the random grain boundary network should be beneficial from the viewpoint of corrosion resistance. [ABSTRACT FROM AUTHOR]

The effect of cold rotary swaging on texture of a metastable austenitic stainless 321-type steel was studied. Strong two-component (001ǁBA and 111ǁBA) texture was produced in austenite phase during cold rotary swaging. The total fraction of 001ǁBA-oriented grains continuously increased to 35% after a swaging reduction of 80%, while the total fraction of 111ǁBA-oriented grains reached a maximum of 30-35% after a swaging reduction of 40-60% and noticeably decreased afterwards. Strong 101ǁBA texture of martensite was also found. [ABSTRACT FROM AUTHOR]

An experimental study of dependence of the AISI 304 steel surface layer microhardness after nanostructuring burnishing on the technological process parameters was carried out and the optimal combination of values of normal force, feed and the number of tool passes was determined. The experiment was planned to apply the method of Taguchi's L9 typical orthogonal array, which made it possible to rank the loading parameters according to the degree of their influence on the output characteristic of the process and to establish that the maximum contribution to the formation of the surface layer microhardness is made by the number of tool passes. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are very famous for their extraordinary resistance to corrosion, but they lack hardness. To overcome the above problem, several curing processes such as nitriding, carburizing, Carbonitriding, nitrocarburizing and Cyaniding are preferred. The AISI 316 austenitic stainless steel selected for this project work were divided into four specimens of dimensions 8 mm in diameter and 42 mm in length. Among the four samples, three were subjected to salt bath nitriding process for about 60 minutes, 120 minutes and 180 minutes at 570°C, respectively and one sample were kept untreated for comparing the results with the processed ones. Followed by case hardening, the samples were subjected to wear test using a pin-on disc machine at constant load and constant speed, 30N and 1000rpm, respectively. Then the hardness of the three specimens along with the untreated specimen were tested with a Rockwell hardness machine. All samples were undergonewith scanning electron microscopy (SEM) for microstructure analysis. And finallythe treated and untreated specimenresults were examined and compared. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are well known for its good corrosion resistance, but lacks in its ductility and hardness. To get over this, nitriding, carburizing, carbonitriding techniques are preferred. For this project work, AISI 304 Austenitic Stainless Steel of dimensions with 8 mm diameter and 43 mm length were undergone with liquid nitriding process at 60 mins, 120 mins and 180 mins and named as N1, N2 and N3 respectively. The specimens were undergone with wear test after the nitriding process. The wear test were carried out under constant load of 15N and speed of 1500rpm on a pin on disc apparatus. After the wear test, the untreated specimen of austenitic stainless steel was kept aside to compare the final results with the treated specimens. The microstructure were analysed through Scanning Electron Microscope(SEM) and the results were compared. The hardness were measured using the Rockwell hardness machine on all specimens by applying a load of 100 grams for 15 seconds. [ABSTRACT FROM AUTHOR]

In this research, 316L austenitic stainless steel (ASS) and medium carbon steel (MCS) were joined together by resistance spot welding. ERNiCr-3 filler wire in a form of foil was utilized as an interlayer. The microstructure evolution in the heat affected zone (HAZ) and fusion zone (FZ) was investigated. The impact of the welding process on the microhardness was examined. The results showed that the HAZ underwent a martensitic transformation near the fusion boundary. The FZ consisted of austenitic solidified microstructure with columnar dendritic solidification mode in as-welded joint, and cellular mode with the application of foil. The average microhardness values recorded in the base metal were 200 HV in the MCS and 220 HV in ASS. In the HAZ, the hardness increased to 400 HV due to the effect of martensite formation. While on the ASS side, the hardness remained at the same level. The big impact of the dissimilar welding on the microhardness was recorded in the FZ. The hardness raised to 680 HV in the as-welded joints and reduced to 530 HV when the foil was applied. [ABSTRACT FROM AUTHOR]

Laser surface modification treatments have been applied to samples of a metastable austenitic stainless steel AISI 301LN. The amount of residual stresses and the presence of induced α´-martensite phase on the surface and subsurface of the samples, as a consequence of laser modification, have been investigated in this study. X-ray diffraction has been used to measure these values, which is a non-destructive method. Laser modification has been applied as parallel lines at a distance of 40 µm, using a laser intensity of 4 A and scanning speeds of 1, 3, and 5 bits/ms, frequency had a constant value of 1000 Hz. The results of the phase analysis show an increase in the α´-martensite present in the surface modified by the laser and that the sample corresponding to the lowest laser speed has the highest martensite fraction. Also, high tensile residual stresses were generated, more pronounced for the lowest laser scanning speed. [ABSTRACT FROM AUTHOR]

Austenitic stainless Fe-0.1C-16Cr-13Ni-2Mo (wt. %) steel was subjected to cold swaging with strain ≤95%. In the cross-section of the cold-swaged bar, the gradient structure was observed. The dynamic mechanical behavior of the program steel was studied by the Charpy V-notch impact testing at room temperature. It was found that impact toughness and impact plane-strain fracture toughness (KId) decreased dramatically after a 20% swaging reduction. In the reduction range of 20-95%, stabilization of impact toughness and impact plane-strain fracture toughness was derived at the level of 0.6-0.8 MJ/m2 and 71-83 MPa×m1/2, respectively. Meanwhile, the stress at general yield (σye) and maximum stress (σm) increased with swaging reduction. The fracture surfaces of specimens after Charpy V-notch impact testing were examined. [ABSTRACT FROM AUTHOR]

Low-temperature hybrid gas diffusion heat treatment process on austenitic stainless steel will result in the S phase layer formation. This work focuses on the influence of temperature towards the S phase layer development on ASTM F138 stainless steel using a hybrid gas diffusion process. The hybrid process performed at different temperature of 400°C, 425°C, 450°C, 475°C and 500°C for 6 hours of treatment time. Meanwhile, the gas composition of NH3, CH4 and N2 is maintained at 80%, 10% and 10%, respectively. Based on the XRD and micrograph analysis from the scanning electron microscope, as the treatment temperature increase, the S phase layer thickness increases. The maximum layer thickness obtained is 10.1µm at a treatment temperature of 500°C however, the XRD analysis confirms the attendance of chromium nitride precipitation, which will deteriorate the corrosion resistivity of the heat-treated material. At 400°C, no visible S phase layer is found, and the uniform S phase layer can be obtained at a temperature above 425°C. In conclusion, the suggested treatment temperature for the low-temperature hybrid gas diffusion heat treatment process for industrial application should starts at 425°C to 475°C to maintain the S phase layer uniformity and avoid the traces of chromium precipitation. [ABSTRACT FROM AUTHOR]

Austenitic stainless steel (AISI) 304 is known to have excellent corrosion resistance under atmospheric conditions. However, corrosion resistance in austenitic stainless steel 304 can decrease in a medium containing chloride ions. In this work, the effects of the concentration of sodium chloride solution on microstructure, crystal phases, elemental composition, and corrosion behavior of AISI 304 were focused on by using a digital light microscope, SEM-EDS, XRD, XRF, and linear sweep voltammetry techniques. Various sodium chloride concentrations were prepared at 1%; 2%; 3.5%; 4%; and 5%. The AISI 304 samples were treated mechanically by polishing on the surface, then comparing it to the unpolished samples. Austenitic and ferrite phases were observed in a cubic structure. Iron (Fe), chromium (Cr), nickel (Ni), manganese (Mn), and carbon (C) were found as the major elements. After the AISI 304 samples were immersed in a chlorinated solution, the corrosion from pitting, intergranular, and rust was observed only on the surfaces of the unpolished samples. However, the changes for the crystal structures and major elemental compositions were insignificant when the concentration of chlorinated solution increased. On the other hand, an increase in the corrosion rate was observed. The lowest corrosion resistance of AISI 304 was found at 5% NaCl. When the NaCl concentration increased, the corrosion rate increased. [ABSTRACT FROM AUTHOR]

Nitride based coatings are widely used in medical applications considering their wear resistance and mechanical properties. Among these coating, chromium nitride are especially interesting because they have good tribological properties. The wear behavior of nitride coatings over SS 316L steel surface have been studied. Here, the austenitic stainless steel is coated by a thin layer of chromium nitride using Cathodic Arc Deposition (CAD) technique. The various wear mechanism have been analyzed at different process parameters such as load, time, velocity and sliding distance. The microstructure and the worn surface studies validated the incidental wear mechanism of the contact interface. [ABSTRACT FROM AUTHOR]

In our Regular busy life for Making, cutting vegetables is also a tedious and time consuming Process. So lot of innovations made, many cutting machine are came into the world market. The investigation of this vegetable cutting machine is from the drawbacks of some of the vegetable cutting machine such as high investment cost, contamination, and floor space. Vegetable cutting machine designed to slice the vegetables into small and similar pieces with good finishes. By using rotary motion, which is transferred by motors to blades and cutting takes place. Machine consist frame with motor, slicing chamber, hopper/feeder and wedge bar. Its cutting blades which are angled at 120° from each other and provide a slicing thickness is 0.2 mm. The vegetable are to be feed through the hopper. The quantity of vegetable to be feed through the hopper depends on size and texture. It sliced into smaller size by the help of 3 rotating blades angled at 120°. A wedge bar is placed at the beneath of rotating blades just to traps the sliced vegetable. A tray carrier is placed at the bottom of the rotating disc to collect the sliced vegetables. The speed of the motor can be regulated depending on size and type of vegetable. The innovative work is focused on design and development of an improved version of vegetable cutting machine. This machine comes up with various contacting parts that is made up of austenitic stainless steel is completely hygiene. The shaft, discs and blades are easy to clean and hence hygiene. [ABSTRACT FROM AUTHOR]

Weld joints are the weakest area and most common failure location in welded structures. In this research, gas metal arc welding (GMAW) process of dissimilar metals between AISI 304 austenitic stainless steel and ASTM A36 low carbon steel was carried out under varying preheating temperatures of 100, 150 and 200°C with filler metal used of ER 70S-6. Subsequently, several experiments were conducted including microstructure observation using optical microscope, Vickers microhardness test, tensile tests, V-notched Charpy impact test and corrosion test using potentiodynamic polarization test in 3.5% NaCl solution. Results show that increasing preheat temperature produces coarser grains in heat affected zone (HAZ) of ASTM A36 carbon steel whilst the amount of delta ferrite in the HAZ of AISI 304 austenitic stainless steel is increased as well. The microstructure in the weld metal region is martensite for all dissimilar metal weld joints under study and an increase in preheat temperature changes the microstructure from plate martensite to lath martensite. The best preheat temperature which results in highest value of tensile strength and Charpy impact toughness is achieved at the preheating temperature of 100°C owing to microstructure formed at the weld metal and HAZ regions. [ABSTRACT FROM AUTHOR]

Hydrocarbon leaks from piping in petroleum refinery or petrochemical plant is a process safety concern that can affect safety of personnel and plant efficiency. Piping leaks can be caused by many factors. One of the most common causes is corrosion that results in wall thinning before leaking. In some extent, consistent vibration of the pipe will also lead to crack formation and subsequently leakage. Thinning pipes may be repaired without shutting down the plant depending on the severity of the wall loss. There are ways to perform online repair on process piping as specified by American Petroleum Institute (API) 570 Piping Inspection Code. For example, it can be repaired by performing on-stream welding either by using full encirclement welded split sleeve enclosure or patch, or by weld build up repair. The former is categorized as temporary repair. In this paper, a study was performed to examine two methods of on-stream welding repair namely build up welding and patch welding, and to investigate the effect on temperature and integrity of the piping. The specimen used was a 10-inch Schedule 10 ASTM A/SA312 TP304L Austenitic Stainless Steel pipe. A mock test rig that represents the actual site condition was prepared. Burn through marks and maximum inner surface temperature of the pipe were examined. The results suggest that build up welding method is too risky to be performed as on-stream repair as the inner surface temperature is too high which will cause the flammable product inside the pipe to ignite and lead to fire. [ABSTRACT FROM AUTHOR]

Austenitic Stainless steel finds wide applications in industrial as well as domestic usage. Because to its outstanding physical characteristics as well as mechanical and chemical properties, Austenitic stainless steels are being largely utilized for architectural applications such as water and fire features, coil material and equipments for vaporizers, mining, chemical, cryogenic, food, dairy and pharmaceutical industries atomic industries etc. Different welding processes have been successfully implemented for welding different variants of Austenitic stainless steel. In this paper, various welding techniques which have successfully utilized to weld different grades of austenitic stainless steel have been thoroughly reviewed. [ABSTRACT FROM AUTHOR]

Austenitic stainless steel 316 L(N) behaviour due to tension load at elevated temperatures must be considered since the abnormal strain hardening may not be predicted. The abnormal strain hardening at the plastic region may appear with various type of serrated yielding. In this study, the austenitic stainless steel 316 L(N) was investigated under tension load for various temperature with the range of 24 °C–655 °C at 10−5/s of deformation rate. The specimens are cylindrical, following the ASTM standard. During the test, the thermocouple was attached to the surface of the specimen. In this preliminary study, the results were to obtain the area of serrated yielding that occurred from the ultimate tensile strength, yield strength, and constant material values of flow relationship. [ABSTRACT FROM AUTHOR]

The wear and surface characteristics of the products are very important to decide the quality of the products. The surface engineering is a multidisciplinary task intended to tailor made the properties of the engineering components due to which their serviceability and function can be improved. In the present experimental work, SS 315 austenitic stainless steel was chosen as substrate materials and zirconium powder was coated on substrate using physical vapour deposition technique. The coated and uncoated specimens were tested for its surface finish by non-contact surface roughness tester and wear characteristics using pin on disc apparatus. The results were compared and it revealed that the surface finish of the zirconium coated specimen is higher than uncoated specimen due to the deposition of the fine particles over the substrate. It was noticed that the weight loss of coated specimen is less than uncoated specimen. The wear rate of the coated and uncoated specimen was calculated as 2.14 grams/m and 3.57 grams/m respectively. The wear resistance of the coated specimen was improved over uncoated specimen. The specific wear rate of the coated specimen was observed as 0.107 grams / Nm and uncoated specimen was observed as 0.1785 grams/Nm. [ABSTRACT FROM AUTHOR]

The possibilities of surface strain hardening of austenitic stainless chromium-nickel steel AISI 321 (04Cr17Ni 8MnMoTi) using conventional ultrasonic impact treatment and a new method of ultrasonic impact-friction treatment with the tool tilt angles in the range of 90°–60° under conditions of limited lubricant supply were studied. Ultrasonic impactfriction treatment significantly improves the efficiency of surface hardening (up to 2.4 times) due to activation of shear deformation processes and, therefore, grain structure refinement. It is shown that a more acute angle between the tool axis and treated surface raises the amount of strain-induced α'-martensite in the surface layer, as well as leads to roughening of the surface microrelief. [ABSTRACT FROM AUTHOR]

The relationship between the microstructural changes and the yield strength of a 316L austenitic stainless steel subjected to plate rolling at temperatures of 200 and 300°C with 40, 65, 85 and 95% rolling reductions was studied. The structural changes during rolling at studied temperatures were characterized by the development of deformation twinning and micro-shear banding that led to a reduction of the transverse grain size. The martensitic transformation hardly developed during rolling at 200°C, when the martensite fraction did not exceed 5% after 95% rolling reduction, and did not occur at all during rolling at 300°C. The grain refinement was accompanied by an increase in the yield strength from 670 to 1240 MPa depending on the rolling regimes. The shape of the stress-strain curves also strongly depended on the rolling temperature and reduction. The shape of the stress–strain curve was characterized by a long plateau-like region right after yielding in the samples subjected to rolling at 300°C with 40 and 65% rolling reductions. A decrease in the rolling temperature and/or increase in the rolling reduction shortened plateau region followed by its disappearance. The effect of rolling conditions on the evolved microstructures and the mechanical properties is discussed in some detail. [ABSTRACT FROM AUTHOR]

The review paper substantiates the advantages of combined methods for the processing of metal surfaces by laser quenching and gas-powder laser cladding, thermal annealing, nanostructuring deformation treatments with sliding indenters and the formation of high-strength nanocomposite thin-film coatings on pre-hardened surfaces of austenitic structural steels and stainless steel synthesized by selective laser melting (SLM) and discusses the prospects of their further development. [ABSTRACT FROM AUTHOR]

This work aims to study the relationship between the velocity of ultrasound and the strength and ductility characteristics of a Fe–18 wt % Cr–10 wt % Ni austenitic stainless steel under uniaxial tension in the temperature range of 143 K ≤ T ≤ 420 K. The release of the martensite phase during loading with a decrease in temperature is found to lead to a significant increase in strength and microhardness and a change in acoustic parameters. According to the experimental results, the relationships between the ultrasound speed and the strength characteristics of steel are established in the mentioned temperature range. Finally, the attenuation coefficient is shown to be a reliable diagnostic parameter of the phase state of austenitic steel under plastic deformation. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are well known for their excellent corrosion resistance based on their high contents of chromium and nickel, which stimulate the formation of stable and passive oxide layers (Cr2O3) on the surface. Due to the limited hardness, wear, and corrosion properties of the austenitic stainless steel, for some applications, their surface needs to be treated. In this study, we choose the plasma carbonitriding technique to improve the surface properties of austenitic SS 316L steel. For this purpose, the experiment was carried out for various processing time such as 1 hour, 2 hours, 3 hours, 4 hours, and 5 hours at 1.6 mbar, 903 V, 408 mA, and 508 °C. As a carbon and nitrogen source, we use a mixture of 3.05 % of CH4, 19.31 % of H2, and N2 balance. Surface properties of untreated and treated samples were characterized by their hardness, surface morphology, chemical composition, and corrosion resistance using microhardness tester, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and potentiodynamic, respectively. It has been found that the hardness increased by a factor of 1.94. From the measurement of profile depth hardness, it is found that the diffusion depth is around 129 µm, the surface of the polished (untreated) sample is very smooth, after being carbonitrided the surface becomes rough and grain boundary cavities were observed. The carbon content is 44.40 mass % and the nitrogen content is 22.45 mass %. From the corrosion test, it is found that all treated samples show the deteriorating corrosion resistance or drop in the corrosion properties. [ABSTRACT FROM AUTHOR]

Corrosion is one of the negative effects influencing the current structural materials of nuclear power plants. The adequate corrosion resistance of structural materials, including austenitic stainless steels, has to be also considered in new designs of nuclear power plants. One of the approaches leading to the improvement of the corrosion resistance of steels goes through surface modifications. In this work, the influence of specimens surface treatment on their corrosion resistance was studied on materials for supercritical water reactor (SCWR) applications. The surface of the steels was prepared by different techniques, including sandblasting, polishing, shot peening and machining, in order to obtain information on the point defects behaviour after exposure to the supercritical water for various exposure times. The microstructural changes of studied steels 800HT and 310S were investigated by Pulsed Low Energy Positron System (PLEPS) [1,2]. A very distinct depth profile of point defects was observed in polished specimens, and the results indicate a significant decrease of the positron diffusion towards the surface in all mechanically modified samples. The increase of the SCW exposure time led to a clearly visible change in the obtained positron lifetimes, i.e., in the size of microstructural defects. [ABSTRACT FROM AUTHOR]

In this work, microstructure and tensile properties are correlated with pitting corrosion of dissimilar and similar gas tungsten arc (GTA) welds of austenitic stainless steel (AISI 304) and ferritic stainless steel (AISI 430). Aim of the work is to determine the effect of two filler metals namely, austenitic stainless steel (AISI 308) and ferritic stainless steel (AISI 430) on microstructure, tensile properties and pitting corrosion of GTA welds. Three regions of weldments, fusion zone, heat affected zone (HAZ) and base metal were tested for pitting corrosion using potentio-dynamic polarization test in 3.5% NaCl environment. Tensile tests were carried out and failure locations were recorded. Optical microscopy was carried out on all weldments before and after corrosion testing, so as to correlate the microstructure and mechanical properties with the corrosion behaviour. In both dissimilar and similar stainless steel joining, welds made with austenitic filler wire were found to be having improved strength with good ductility when compared to that of welds made with ferritic filler wire. Relatively higher number of corrosion pits was observed in welds made with ferritic filler wire resulting in poor corrosion resistance. Comparison of pitting potentials across the dissimilar welds shown clearly that relatively higher positive potentials were obtained with austenitic filler resulting in better corrosion resistance. Hence, from present study it can be concluded that austenite filler wire is best suited for both dissimilar and similar stainless steel welding in terms of both strength and pitting corrosion resistance. [ABSTRACT FROM AUTHOR]

Martensitic stainless steels are commonly used in nuclear power plants, steam generators, pressure vessels, and turbine blades. CA6NM stainless steel is one of the martensitic stainless steels primarily prescribed to use for the steam turbine blade application. Pitting corrosion is one of the most common problems which could cause fatigue failure in the turbine blade application. Herein, we study the effect of tempering treatment on pitting corrosion resistance of modified cast CA6NM stainless steel in a 3.5 % NaCl solution. Three different CA6NM materials were used in this experiment: samples with an addition of 1 % Mo, 2 % Mo, and 2 % Mo-1 % N. The CA6NM stainless steel specimens were heated using heating furnace to 1050 °C for 3 hours and quenched to room temperature. Furthermore, tempering treatment was applied to the CA6NM stainless steel samples which were conducted in two types, single and double tempered. The open circuit potential measurement showed that samples with an addition of 2 % Mo-1 % N and double tempered had the highest free corrosion potential value of all the samples. The cyclic polarization test was conducted in a 3.5 % NaCl solution. The highest pitting potential was found in CA6NM with the addition of 2 % of molybdenum content with double tempered treatment. [ABSTRACT FROM AUTHOR]

Friction welding is a process of connecting metals without fusion or namely is solid state process, where the welding process occurs as a result of friction through the merger between the rotation speeds of one of the rotating workpieces. This research is concerned with studying the forging pressures and welding times of the microstructure and mechanical properties of a dissimilar metal weldment between AISI-316 austenitic stainless steel and AISI-4140 alloy steel. Forging pressure variations used 110 kg/cm2, 130 kg/cm2 and 150 kg/cm2, while the welding time variations used were 35 seconds, 50 seconds and 65 seconds. Friction welding had operates with a high speed rotation of 1800 rpm. The results of the study showed that the increased variation in forging pressure and welding time resulted in a reduction in the specimen length, due to the lubrication process in the welding joints of the two materials. The results of the microstructure are seen grain coarsened occurs in the HAZ region the shape and size of the grain is different when compared to the parent metal. The mean hardness of the welding area interface is 332 HVN. The hardness value is lower than the hardness of the AISI-4140 parent metal, but it is higher than the AISI-316 parent metal. The hardness value of the AISI-4140 parent metal material is 354.7 HVN. While the parent metal material AISI-316 averages 183.5 HVN. The optimal tensile strength value is produced at a variation of forging pressure 130 kg/cm2 of variation of friction time of 35 seconds with a value of 455.02 N/ mm2. [ABSTRACT FROM AUTHOR]

Stainless steel need to be protected against corrosion. Ceramic oxides exhibit superior corrosion barrier performance in its nano structured form. In this paper, the effect of depositing Zn doped ZrO2 on the corrosion inhibition of S.S. 304 austenitic stainless steel was experimentally studied. The design of experiments approach of Taguchi Methodology was used for systematically varying the coating process variables. Corrosion performance was evaluated using standard techniques. The results highlight the superior barrier properties of the Zn doped ZrO2 coatings in NaCl environments. [ABSTRACT FROM AUTHOR]

Friction welding is a solid state welding process to produce the joint by utilizing heat generated by friction at the interface and with axial pressure. Friction welding process is non consumable and reusable in manufacturing process. This method produces the joint between similar and dissimilar metals without much effecting heat affected zone. The conventional welding technique is very difficult to join dissimilar metals as they are differing in their thermal and metallurgical properties. Welding of dissimilar metals is very much interested in automotive, aerospace and other industrial applications. The aluminium alloy in combination with steel bodies has significant reduction in weight and cost saving. In this present work a continuous drive friction welding process was performed on dissimilar material AA2219 aluminium alloy and AISI 304 austenitic stainless steel. The study was carried on process parameters like rotational speed, Heating Pressure, Upsetting Pressure, Heating time, and Upset time that are influenced on friction welding process. The experiment was conducted for different combination of process parameter to identify the optimal. The strength of the welded joints is varied with heating pressure and increasing with upset pressure at constant upset time and friction time. The welded joints strength was examined with tensile strength and was tabulated. The hardness distribution at the joint interface was noted and plotted a hardness peak was observed at interface. Micro structural observation was also done characterize the joint. It was observed that burn of length is one parameter that plays vital role on wastage metal in the welding process. [ABSTRACT FROM AUTHOR]

Cellular automata-finite difference framework is employed to estimate the influence of the hatch distance on the resulting microstructure of 316 L austenitic stainless steel fabricated by selective laser melting. The grain structure is found to be significantly affected by the hatch distance, including both the grain morphology and crystallographic texture. The smaller the hatch distance, the more severe the texture, the smaller the number of fine grains observed in the microstructure pattern, and the more pronounced the Goss texture component in the case of employed process parameters. [ABSTRACT FROM AUTHOR]

The peculiarities of hydrogen embrittlement of niobium-alloyed austenitic stainless steel produced by wire-feed electron-beam additive manufacturing (EBAM) method have been investigated. After EBAM-growth, the Nb-alloyed steel has had macroscopically and microscopically heterogeneous structure, which has been characterized by austenitic matrix with colonies of ferritic dendrites and Nb-enriched precipitates. Hydrogen-charging causes the increase in the yield strength and the ultimate tensile stress of EBAM-produced specimens relative to hydrogen-free specimens and assists to surface brittle cracking of the specimens. Fracture surface in hydrogen-charged specimens includes several characteristic regions: surface brittle layers (20–25 µm) fractured both in transgranular and intergranular modes, subsurface hydrogen-affected zone (35–45 µm) with elongated dimples and flat facets (transgranular mode), and ductile central part with dimple micromechanism of fracture (transgranular mode). [ABSTRACT FROM AUTHOR]

The effect of ion-plasma treatment (IPT) on tensile yield strength and microhardness in the 316L austenitic stainless steel specimens with grain-subgrained (d<0.5 µm), fine-grained (d=6 µm) and coarse-grained (d=55 µm) structures has been studied. As a result of IPT, the yield strength and microhardness of the specimens increase. The mechanisms responsible for the variation in the yield strength after IPT strongly depend on the initial structural state in steel—density of intergranular boundaries and defects of a crystal structure. The increase in microhardness in the surface layers of the specimens and their yield strength is determined by both solid-solution strengthening and precipitation hardening, regardless of the type of initial structure in them. [ABSTRACT FROM AUTHOR]

Phase composition, tensile properties, and fracture micromechanisms of austenitic stainless steel Fe-17Cr-13Ni-1.7Mn-2.7Mo-0.5Si-0.01C (wt %) specimens after ion-plasma nitriding in the mixture of gases (30% nitrogen and 62% argon) with the addition of 8% hydrogen were experimentally studied. Nitrided layer is characterized by the heterogeneous phase composition, which includes nitrogen-enriched austenite (Fe-γN), ordered nitrogen-enriched (Fe4N) phase and a small amount of CrN and Fe-α phases. The diffusion layer is characterized mainly by Fe-γN phase. The addition of hydrogen in saturating gas enhances the diffusion of nitrogen during ion-plasma treatment, and deeper nitrogen-assisted surface and subsurface layers are formed in comparison with specimens treated in H-free gas mixture. Ion-plasma nitriding leads to an increase in the yield strength of the specimens and a decrease in ductility. Fracture surface in nitrided specimens contains several characteristic regions fractured in transgranular mode: surface quasi-brittle layer with cleavage-like facets, subsurface nitrogen-assisted diffusion layer with elongated dimples and numerous traces of deformation, and nitrogen-free ductile matrix with dimple fracture micromechanism. [ABSTRACT FROM AUTHOR]

The present work is devoted to the study of macroscopic localization of plastic deformation of AISI 321 austenitic stainless steel within a temperature range of 143–300 K, which was chosen in view of the direct martensitic transformation γ → α'. Visualization and evolution of bands of macroscopic localized plastic deformation at the stages of linear strain hardening was carried out by the method of double-exposure speckle photography. Analysis of deformation curves made it possible to identify the following stages: the stage of linear work hardening, the stage of jerky flow, and the yield plateau (at low temperature). An analysis of the distributions of local deformations showed that a system of equidistant mobile localized-strain centers is observed at the stages of linear work hardening. It has been established that lowering the temperature leads to a change in both the duration of the strain hardening stages and localization parameters of the plastic flow. [ABSTRACT FROM AUTHOR]

The work is aimed at detection and analysis of the formation regularities of phase composition, defective substructure, mechanical (microhardness) and tribological (wear parameter and friction coefficient) properties of high-chromium austenitic stainless steel of AISI 304 grade, subjected to borating in the scheme of plasma-assisted RF-sputtering of boron cathode. The formation of multiphase multi-layer hierarchically organized structure in the surface layer with thickness up to 40 µm is revealed. It is characterized by high wear resistance, which exceeds that of initial steel by more than 100 times. It is shown that the main mechanisms of strengthening the modified layer are solid solution strengthening, due to saturation of iron crystal lattice with boron, and dispersion strengthening, connected with extraction of nanosized particles of boride phase. [ABSTRACT FROM AUTHOR]

The fan blades and turbine blades in a jet engine are severely damaged by high-velocity impingements of various foreign objects. In our recent study, a prediction method of indentation size (PMIS) formed by the high-velocity impingement of a solid sphere has been established based on an expanding cavity model combined with the Johnson–Cook (JC) flow stress model and energy conservation in the impingement process. The indentation size formed by a high-velocity impingement up to 400 m/s can be estimated using the PMIS with appropriate material constants on a target material on the JC model, which is called JC parameters. In this study, to demonstrate the effectiveness of the PMIS, a high-velocity impingement test of a solid sphere was conducted using three metallic materials: pure copper (ASTM-C10200), austenitic stainless steel (AISI-304), low-carbon steel (AISI-1015). A high-carbon chromium steel ball with a diameter of 4.5 mm was impinged onto these three target materials at several impingement velocities from 50 to 350 m/s. The JC parameters on these three materials were identified via a quasi-static tensile test and a high-speed tensile test under a strain rate of approximately 100 s-1. Results show that the depths of indentation estimated by the PMIS agreed well with the experimental results irrespective of the target material. Consequently, it was demonstrated that the PMIS can effectively estimate the indentation depth formed by the high-velocity impingement of a solid sphere up to 350 m/s. [ABSTRACT FROM AUTHOR]

This paper deals with the impact of parameters related to friction welding such as hardness and tensile strength of AISI 310L austenitic stainless steel by using Taguchi based grey relational analysis. This method was used to decide the optimum conditions of process parameters by which the greater hardness and maximum tensile strength were acquired in friction welding. The investigation and trails were carried out by varying the input parameters such as friction force (FF), upsetting force (UF) and heating time (HT) using Taguchi's L9 based orthogonal array. The experimental outcomes demonstrate that, the hardness of 94 HRB and maximum tensile strength 592.08 MPa was obtained from the joints fabricated as per the optimum level of friction force 4 MPa, upsetting force 5.5 MPa and heating time 8 sec. [ABSTRACT FROM AUTHOR]

This work articulated a study of dissimilar weld on AISI 316L austenitic stainless steel and Incoloy 825 Ni- based alloy using laser welding on its mechanical and microstructural characteristics. Welding was accomplished by Nd:YAG pulsed laser beam welding process. The laser beam welding has certain advantages over other welding techniques due to its less heat affected zone, high power intensity, high repetition rate. This work investigates the process parameters like laser focal diameter, power and pulse frequency in Laser welding for the above dismillar metal plates. Characterization was conducted by optical microscopy, to understand the microstructural changes occured during the welding process. The tensile test, Vickers micro-hardness tests and the properties of weld joints were investigated using Universal testing machine, Vickers micro hardness tester and the optical microscope. The process parameters were fixed based on the design suggested by Taguchi method. Based on the test results after welding, the values were fed into the MINITAB software for optimization. From the ANOVA, the most influencing parameter which affects the mechanical properties were found and the best combination and level of process parameter was found using optimization. [ABSTRACT FROM AUTHOR]

AISI 316L stainless steel is an austenitic stainless steel often used for medical devices, marine structures and chemical and food processing, where corrosion resistance to chlorides is required. Its corrosion resistance can even be further improved by surface treatments. This study intends to explore the effect of surface treatment using water to biocorrosion resistance of the stainless steel. The water treatment was varied in terms of the water's acidity (i.e., pH of 3, pH of 7, and pH of 11), temperature (i.e., 27°C and 90°C), and duration of treatment (i.e., 1 and 6 hours). Corrosion resistance was measured using potentiostat using saline solution, which represents body fluid, as electrolyte. It was found that all the variables (pH, temperature, and duration) affect the steel's corrosion resistance. The results showed that the stainless steel's corrosion resistance reduces with pH and increases with duration of treatment. For the effect of treatment duration, in alkaline environment, the longer the treatment duration the higher the corrosion resistance. But, in acid environment, the longer the treatment duration the lower the corrosion resistance. [ABSTRACT FROM AUTHOR]

Austenitic stainless steel utilized on a vehicle of mass rapid transit have composition 18 wt.% Cr–8 wt.% Ni. This steel is known to have a good corrosion resistant. Because of various pollutions, this material is prone to become less resistant to corrosion. Heat treatment is one of many methods to remedy the corrosion resistance. The material was subjected to heat treatment at 1030 °C for 5 h and 3 h and the other was cooling with various types of cooling, such as quenching. X-ray diffraction was used to characterize the structure because heat treatment modified the structure of these samples; the concentration of iron-alpha increases proportionally to the decrease in corrosion rate. To investigate the electrochemical behavior of these materials, potentiodynamic curves were obtained during the standard corrosion tests before and after heat treatment. The results showed that the full annealing method with rapid quenching is the best method for improving the corrosion-resistance of the austenitic stainless steel, compared to the annealing method with slow cooling. [ABSTRACT FROM AUTHOR]