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The growth of the healthcare sector has attracted a lot of interest to biomedical telemetry. Without regular hospital check-ups and follow-up routine check-ups, it is now possible to remotely monitor a patient's physiological indications. This research work proposes an 18 mm3 implanted antenna with a mainly compact volume for biomedical applications. The performance of the antenna is entirely examined in terms of the SAR values, directive gain, Impedance Bandwidth, and reflection coefficient. The substrate material used in proposed antenna is FR4 epoxy resin, as FR4 plays an important part in adding the bandwidth of the antenna and is far cheaper than Rogers or any other relevant material, therefore giving the device an upper hand over other substrate accoutrement. The proposed antenna is configured to operate in the higher ISM band (5.725 GHz to 5.875 GHz) with an impedance bandwidth of 17.02%. Sorting pins and triangular slots on the patch surface have been introduced, which offer an ISM band, an excellent SAR value of 255.235 W/ Kg, a directive gain of -25.117 dB, and improving the performance of the suggested antenna. Using high frequency structure software (HFSS) tool, detailed analysis of the suggested implantable antenna has been carried out and thoroughly investigated for overall comparison and improvement., {"references":["1.\tNguyen, D., & Seo, C. (2021). An ultra-miniaturized antenna using loading circuit method for medical implant applications. IEEE Access, 9, 111890-111898.","2.\tLiu, C., Guo, Y. X., & Xiao, S. (2016, March). A review of implantable antennas for wireless biomedical devices. In Forum for electromagnetic research methods and application technologies (FERMAT) (Vol. 14, No. 3, pp. 1-11).","3.\tNehra, R. K., & Raghava, N. S. (2021, December). Enhanced Impedance Bandwidth of Highly Compact Implantable Antenna using Magnetodielectric Substrate. In 2021 International Conference on Industrial Electronics Research and Applications (ICIERA) (pp. 1-5). IEEE.","4.\tKhan, A., Alamry, K. A., & Asiri, A. M. (2021). Multifunctional Biopolymers‐Based Composite Materials for Biomedical Applications: A Systematic Review. ChemistrySelect, 6(2), 154-176.","5.\tSalim, M., & Pourziad, A. (2015). A novel reconfigurable spiral-shaped monopole antenna for biomedical applications. Progress In Electromagnetics Research Letters, 57, 79-84.","6.\tAndreuccetti, D. (2012). An Internet resource for the calculation of the dielectric properties of body tissues in the frequency range 10 Hz-100 GHz. http://niremf. ifac. cnr. it/tissprop/.","7.\tKirtonia, P., Hosain, M. K., & Rahman, T. (2018, December). Miniaturized and differentially fed implantable antenna for biomedical telemetry applications. In 2018 10th International Conference on Electrical and Computer Engineering (ICECE) (pp. 349-352). IEEE.","8.\tLiu, R., Zhang, K., Li, Z., Cui, W., Liang, W., Wang, M., ... & Li, E. (2021). A wideband circular polarization implantable antenna for health monitors microsystem. IEEE Antennas and Wireless Propagation Letters, 20(5), 848-852.","9.\tLiu, C., Guo, Y. X., & Xiao, S. (2014). Capacitively loaded circularly polarized implantable patch antenna for ISM band biomedical applications. IEEE transactions on antennas and propagation, 62(5), 2407-2417.","10.\tNehra, R. K., & Raghava, N. S. (2021, October). Highly compact triple ring slotted circular polarized implantable antenna for bio-medical applications. In 2021 6th International Conference on Signal Processing, Computing and Control (ISPCC) (pp. 186-190). IEEE."]}

Supplementary Figure 6 from The SWI/SNF ATPase Brm Is a Gatekeeper of Proliferative Control in Prostate Cancer

Factors that drive prostate cancer progression remain poorly defined, thus hindering the development of new therapeutic strategies. Disseminated tumors are treated through regimens that ablate androgen signaling, as prostate cancer cells require androgen for growth and survival. However, recurrent, incurable tumors that have bypassed the androgen requirement ultimately arise. This study reveals that the Brm ATPase, a component of selected SWI/SNF complexes, has significant antiproliferative functions in the prostate that protect against these transitions. First, we show that targeted ablation of Brm is causative for the development of prostatic hyperplasia in mice. Second, in vivo challenge revealed that Brm−/− epithelia acquire the capacity for lobe-specific, castration-resistant cellular proliferation. Third, investigation of human specimens revealed that Brm mRNA and protein levels are attenuated in prostate cancer. Fourth, Brm down-regulation was associated with an increased proliferative index, consistent with the mouse model. Lastly, gene expression profiling showed that Brm loss alters factors upstream of E2F1; this was confirmed in murine models, wherein Brm loss induced E2F1 deregulation in a tissue-specific manner. Combined, these data identify Brm as a major effector of serum androgen–induced proliferation in the prostate that is disrupted in human disease, and indicate that loss of Brm confers a proliferative advantage in prostate cancer. [Cancer Res 2008;68(24):10154–62]

Supplementary Figures 1-5 and 7 from The SWI/SNF ATPase Brm Is a Gatekeeper of Proliferative Control in Prostate Cancer

Supplementary Figure Legends 1-7 from The SWI/SNF ATPase Brm Is a Gatekeeper of Proliferative Control in Prostate Cancer

Drug induced liver toxicity is a serious health complication leading to high mortality rates and post marketing withdrawal of drugs. Although considered to be the gold standard biomarkers; aspartate aminotransferase, alanine aminotransferase, total bilirubin and alkaline phosphatase have been found to have specificities beyond liver, therefore more specific and predictive markers for the detection of antitubercular drug mediated liver damage are required. Unfortunately, the effectiveness of currently used first line antitubercular drugs namely isoniazid, rifampicin, pyrazinamide is often accompanied with liver injury, impeding the cure of patients. Keeping in view, the prognostic and diagnostic applications of microRNAs in various diseases, we tried to assess the importance of microRNAs 122 and 192 in antitubercular drug associated liver injuries. The study included subjects having tuberculosis of any type with antitubercular drug induced liver injury; naïve or newly diagnosed tuberculosis patients, tuberculosis patients on drugs not having toxicity and healthy controls. Observations from this study revealed that expression levels of miR-122 and miR-192 were significantly decreased in the serum of antitubercular drug induced liver injury patients only. Therefore, these microRNAs or the pathways associated with them can be used as a tool to predict or cure antitubercular drug associated liver injury in future.

Precipitation of Cr-rich carbides, diffusible hydrogen content and heterogeneous microstructure formation across the weldments makes heat-affected zone (HAZ) susceptible to intergranular cracking and makes weldability of creep strength enhanced ferritic (CSEF) Grade P92 steel a critical issue. In the present research work, the Granjon implant test and mercury method (for diffusible hydrogen measurement) have been performed on Grade P92 steel welded specimens to study the effect of welding parameters on diffusible hydrogen levels and their subsequent effect on hydrogen-assisted cracking (HAC). The weld metal was deposited by a shielded metal arc welding process on Grade P92 steel samples using P92 matching filler. The three different welding conditions are used to measure the diffusible hydrogen level in the deposited metal. Granjon implant test was performed to evaluate HAZ HAC susceptibility with similar welding conditions which were used in the mercury method. Lower critical stress (LCS) was also evaluated using the Granjon implant test. The higher susceptibility of CSEF Grade P92 steel welded plate towards HAZ HAC was noticed in case of lower heat input or higher diffusible hydrogen content. However, by considering LCS, fracture mode and diffusible hydrogen content, the weld deposited using the highest heat input (condition III) offers great resistance to HAZ HAC.

Formation of Laves phase in creep strength enhanced ferritic steel is investigated using re-austenitization and tempering treatment. The as-received material is exposed to 620°C for 4560 h aging, a...

Cemento-ossifying fibroma (COF) is a benign fibro-osseous lesion which belongs to the same category of fibrous dysplasia and cement-ossifying dysplasia. It arises from the periodontal membrane which contains multipotent cells that are capable of forming cementum, lamellar bone, and fibrous tissue. It is more common in the mandible than in the maxilla. We present a case of COF in the maxilla, a rare occurrence in a 66-year-old female with the chief complaint of a swelling in the left upper back tooth region for the past 3 years. A panoramic radiograph was taken, which showed an oval radiopaque lesion in the second quadrant from 24 to maxillary tuberosity. In the maxilla, the clinical and radiological differential diagnosis includes fibrous dysplasia, giant cell lesions, cementoblastoma, calcifying epithelial odontogenic tumor, and peripheral giant cell granuloma. It is sharply circumscribed and demarcated from the surrounding bone, so surgical excision is the treatment of choice.

In present research work, discussions have been made to predict the bead geometries and shape profiles of weldments using statistical regression modeling and fuzzy logic techniques. However, the regression and fuzzy logic modeling techniques do not take into account the actual physical properties and phenomena that occur in welding. Moreover, techniques such as regression and fuzzy logic modeling are not suitable for predicting the transient temperature distribution and distortion of arc welded joints. To predict the transient temperature distributions, peak temperature distribution, and residual deformation in welding, deterministic modeling techniques such as thermomechanical analysis are preferred. However, while performing thermomechanical analysis of welded joints, size and reinforcement dimensions of the weld bead need to be incorporated into the model for accurate prediction of transient temperature distributions and distortions. In this work, circularly spread moving heat source has been used for transient thermal modeling of tungsten inert gas (TIG) welding process. In the subsequent sections of this article, the weld thermomechanical analyses for TIG square butt joints are discussed to predict the temperature distributions and angular distortion. The weld dimensions such as weld width, weld depression, and weld bulging have shown great influence on the angular distortion patterns. 1. Introduction The present work describes the thermomechanical analysis of an open arc process, i.e., tungsten inert gas (TIG) welding of square butt joints by considering the circularly spread moving heat source to predict the angular distortion and thermal profile (Pandey et al. 2016). TIG welding is commonly used for thin sheet joining (Pandey et al. 2018a, 2018b). Generally, for thin sheets, the TIG welding is performed autogenously such that no filler material is required. In some special cases, such as for fillet and groove welding, a filler rod is used in the TIG welding process. The distortion of the TIG weld square butt joints is primarily dependent on the weld width, bead depression, and bulging (Mahapatra et al. 2006). If these factors of weld bead geometries are within tolerable limits, then, the distortion observed in the weld joint is minimum. In TIG weld butt joints, the angular distortion is more prominent because of the presence of upper bead depression and lower bead bulging. Finite element analysis (FEA) simulation of TIG welding is highly effective in predicting the thermomechanical behavior such as temperature distributions and distortions. In this work, numerical and experimental approaches have been applied to predict the thermal profile and angular distortion in a TIG open arc welding process. An Finite element (FE) model has been developed for 3-D analysis of TIG square butt joints for predicting angular distortion based on circularly spread moving heat source and weld geometry.

The nuclear grade modified 9Cr 1Mo (P91) and 9Cr-0.5Mo-1.8W V Nb (P92) are commonly used material for power plant components operating in the temperature range of 600–650 °C. For such steels, the creep strength at the elevated operating temperature is the prime criteria. However, microstructure stability and notch toughness also play an important role, especially for the welded joints to meet the pressure test at room temperature. The room temperature mechanical properties of the welded joint are strongly influenced by the welding process, filler composition, composition of the base plate and heat treatment performed after the welding. In present work, P91 and P92 dissimilar multi-pass welded joints have been produced using the different filler rod. The microstructure of the welded joint has been studied for the different filler composition in various heat treatment condition. The room temperature Charpy impact toughness and tensile properties for the different welded joints (different filler) have been also studied and related with the microstructure of the welded joint. From the results, it has been concluded that a higher amount of ferrite stabilizer in P92 filler promotes the formation of the δ ferrite in the weld fusion zone.

Effect of ‘conventional normalizing and tempering’ (CNT) and ‘double austenitization based normalizing and tempering’ (DNT) process on microstructure characteristic and mechanical behavior was studied forP92 steel. In CNT heat treatment, P92 steel is normalized at 1040 °C/air cool and tempered with 760 °C/2 h/air cool. In DNT heat treatment, initially normalizing was performed at 1040 °C for 1 h followed by water quenching. After that sample was normalized in the temperature range of 950–1150 °C for 1 h and tempered at 760 °C/2 h/air cool (950 °C-DNT1, 1050 °C-DNT2, 1150 °C-DNT3).Grain size for CNT and DNT1 treatment were measured 17 ± 7 μm and 12 ± 5 μm. A DNT treatment resulted in homogeneous microstructure formation that led to improved mechanical properties as compared to CNT treatment. The DN based heat treatment produced complete martensitic microstructure formation by complete dissolution of carbide precipitates. The optimized room temperature condition was obtained for the DNT 1 heat treatment.

An autogenous gas tungsten arc welded P92 weld joint was subjected to two different post weld heat treatment (PWHT). One PWHT involved tempering of the as-welded sample at 760 °C for 2 h (referred to as PWDT) followed by natural air cooling. The other PWHT involved normalizing (re-austenitizing) the as-welded sample at 1040 °C for 40 min followed by PWDT (referred as PWNT). The cross-section of the as-welded sample exhibited a higher degree of microstructural heterogeneity. Both the PWDT and PWNT heat treatment procedures reduced the heterogeneity gradient along the weld cross section. The heat affected zone (HAZ) of the as-welded and PWDT samples showed Charpy toughness values of 3 ± 4 J and 64 ± 6 J, respectively, which were lower than that of the base metal (72 ± 5 J). The PWNT treated sample exhibited a HAZ Charpy toughness value of 83 ± 4 J which was higher than that of the base metal. The brittle mode of the fracture with river patterns was observed for the as-welded and PWDT treated sample while a ductile mode of fracture with fine and shallow dimples was observed for the PWNT condition. The PWNT treatment resulted in dissolution of the ferrite patches and formation of a uniform microstructure along the weld cross section. The PWNT treated samples exhibited the lowest yield strength to tensile strength ratio supporting the enhanced ductility as a result of this re-austenizing heat treatment. The as-welded and PWDT treated weld joints showed the presence of detrimental δ ferrite phase in the weld fusion zone and the coarse grained heat affected zone. The PWNT completely removed the δ ferrite patches from the microstructure whereas the PWDT treatment merely reduced the range of the hardness of the δ ferrite from 179 to 301 HV (as welded) to 204–228 HV.

This study explores perceptions of employers towards online degree holders (graduates, post-graduates, doctoral) for hiring and promotion decisions in Technology Services Industry in India.

This study explores perceptions of employers towards online degree holders for hiring and promotion decisions in Technology Services Industry in India.

P91 steel weld joint was prepared using the shielded metal arc welding process and four different conditions of weld consumable that provide the different levels of diffusible hydrogen in deposited metal. In the present research, the effects of diffusible hydrogen content on the flexural strength, lower critical stress, and tensile strength of P91 steel welds were also determined with respect to different electrode conditions. To investigate the effect of diffusible hydrogen on multipass welding, top and root side flexural tests were performed. The residual stresses (axial stress and transverse stress) were also measured using the blind hole drilling method for different conditions of welding consumable. The peak value of residual stresses was measured at the center of the weld fusion zone. The maximum value of transverse stress was measured to be 355 MPa for case II (6.21 mL/100 g of diffusible hydrogen), while the maximum axial stress was about 218 MPa for case IV (12.43 mL/100 g of diffusible hydrogen). A three-dimensional finite element simulation was also performed to predict the residual stress distribution and thermal profile along the welded joint. The experimentally determined residual stresses correlated well with the numerically estimated residual stresses. The diffusible hydrogen content was not observed to have any significant effect on the residual stresses. The corrected residual stress values were also predicted by considering the plasticity-induced error. However, the flexural performance of the welded joint was affected by the diffusible hydrogen content. The top and root flexural strength was measured to be optimum for the low level of diffusible hydrogen content, and the values decreased with an increase in diffusible hydrogen content.

In the present investigation, P92 steel weld joints were prepared using a shielded metal arc welding (SMAW) process for two different fillers, E911 and P92. A comparative study was performed on the microstructural evolution, tensile strength, microhardness, and Charpy toughness across the P92 steel weldments in the as-welded and post-weld heat-treated (PWHT) conditions. The PWHT was performed at 760 °C for 2 hours. To study the effect of the different filler metals and PWHT on the mechanical properties, longitudinal and transverse tensile tests were carried out at room temperature for a constant cross-head speed of 1 mm/min. In the longitudinal direction, the tensile strength of the P92 steel welds was measured as 958 ± 35 and 1359 ± 38 MPa for the E911 and P92 filler, respectively. In the as-welded condition, the transverse tensile specimens were fractured from the fine-grained heat-affected zone or inter-critical heat-affected zone (FGHAZ/ICHAZ) and, after PWHT, the fracture location was shifted to over-tempered base metal from the FGHAZ/ICHAZ. After the PWHT, the tempering reaction resulted in lowering of the hardness throughout the weldment. After PWHT, the Charpy toughness of the weld fusion zone and heat-affected zone (HAZ) of the E911 filler weldments was measured as 66 ± 5 and 142 ± 8 J, respectively. The minimum required Charpy toughness of 47 J (EN1557: 1997) was achieved after the PWHT for both E911 and P92 filler.

Ferritic/martensitic 9Cr-1Mo-V-Nb steel also designated as ASTM A335 used in construction of several components of power plants operating in temperature range of 600–650 °C. In present investigation, dissimilar weld joint of P91 and P92 steel were prepared using the autogenous tungsten inert gas (A-TIG) welding and multi-pass gas tungsten arc welding (GTAW) process. A comparative study was performed on evolution of δ-ferrite patches in weld fusion zone and heat affected zones (HAZs) of welded joints. The evolution of δ-ferrite patches was studied in as-welded and post-weld heat treatment (PWHT) condition. PWHT was carried out at 760 °C for tempering time of 2 h and 6 h, for both A-TIG and GTA weld joints. It was observed that presence of higher content of ferrite stabilizer in P92 steel promote the formation of δ-ferrite patches in weld fusion zone as well as HAZs. To study the effect of welding process and PWHT, Charpy V impact energy and microhardness tests were performed. For microstructure characterization, field-emission scanning electron microscope (FESEM) and optical microscope were utilized.

In creep-strength-enhanced ferritic steels, hydrogen-induced cold cracking of weldments is a serious issue. In the present research work, the effect of cooling medium on tensile properties and microstructure evolution of P91 steel weldments has been studied. For water-cooling condition, the diffusible hydrogen metal in deposited metal was measured by the mercury method. The microstructure of weldments in different cooling condition was characterized by using the field-emission scanning electron microscope (FE-SEM) and optical microscope. The fractured tensile test samples were characterized using the FE-SEM. The maximum tensile strength was measured to be 624 MPa for air-cooling medium (very low level of diffusible hydrogen).

Friction stir processing (FSP) is a novel process for refinement of microstructure, improvement of material’s mechanical properties and production of surface layer composites. In present investigation, composite reinforced with using Zn/ MoS2 powder in as-cast alloy were developed at tool rotational speed of 664 rpm and tool transverse speed of 26 mm/min using FSP. Microstructural observation of MoS2/Zn reinforced composites confirmed the fine and equiaxed grains in the stir zone (SZ) and distribution of fine reinforced particles of MoS2/Zn in SZ. Moreover, agglomeration of MoS2/Zn particles were not observed. The ultimate tensile strength was measured to be 113 ± 9 and 82 ± 7 MPa for MoS2and Zn reinforced Al-Si alloy, respectively. The sliding wear was studied using pin-on-disk tribometer and it was found that FSP enhanced the wear resistance of the as-cast alloy. The MoS2 reinforced composite showed superior wear resistance than Zn reinforced composite and base material. To understand the acting wear mechanism, the field emission scanning electron microscope (FESEM) of worn out surfaces were performed.

In present research article, microstructure evolution in P91 steel and their weldments are reviewed in as-virgin and heat treatment and creep exposure condition. The thermal stability of P91 steel is derived from solid solution strengthening, sub-grain hardening and precipitation hardening. The initial microstructure plays an important role in deciding the mechanical properties of P91 steel and their weldment in long-term ageing and creep exposure condition. Effects of various alloying elements present in P91 steel and their related phase have also been discussed in details. The role of grain coarsening, Cr/Fe ratio, lath widening and dislocation density on creep rupture life of base metal and weldments are discussed. The combined effects of lath martensitic microstructure, residual stress and diffusible hydrogen content on performance of P91 steel material are also discussed.

Before putting in service, the creep strength enhanced ferritic (CSEF) steels are subjected to varying tempering treatment to produce a vast array of mechanical properties and to achieve the optimum combination of microstructure and mechanical properties by controlling normalizing and tempering temperature/time. In the present investigation, P911 steel was subjected to a fixed normalizing temperature of 1040 °C for 1 h and then, subjected to varying tempering temperature (720 °C–800 °C) for 2 h of tempering time. The effect of notch geometry on the tensile properties with respect to the varying tempering temperature was also investigated. The microstructural characterization was studied using optical microscope and field-emission scanning electron microscope (FESEM). A decrease in grain size, hardness and strength were noticed with increase in tempering temperature initially but after 740 °C, the grain size and strength were found to be increased continuously. The area fraction of precipitates was found to be varied inversely with the grain size. For a particular tempering temperature, an increase in notch depth resulted in increase in strength and decrease in ductility. The best combination of hardness, ductility and strength were achieved after normalized at 1040 °C for 1 h and tempered at 760 °C for 2 h.

The aim of the characterization of P911 steel is to determine the consequence of different tempering temperature on nano-size particle evolution and their effect on the mechanical properties. P911 steel was normalized at 1040 °C for 1 h and subjected to varying tempering condition in the range of 720–800 °C for 2 h of tempering time. To study the effect of tempering temperature on nano-size particles distribution and grain size of P911 steel, field-emission scanning electron microscope (FESEM) and optical microscope (OM) were utilized. The other tests were hardness measurement and room-temperature tensile testing was performed to characterize the P911 steel for different tempering condition. The ultimate tensile strength (UTS) and hardness have found a great dependency on the area fraction of precipitates present in the microstructure. The UTS and hardness were observed to be increased continuously with increase in tempering temperature in range of 720–800 °C.

Ferritic/martensitic 9Cr-1Mo-V-Nb steel also designated as ASTM A335 used in construction of several components of power plants operating in temperature range of 600–650 °C. In present investigation, dissimilar weld joints of P91 and P92 steel were prepared using the autogenous tungsten inert gas welding (A-TIG) and multi-pass gas tungsten arc (GTA) welding process. A comparative was performed on evolution of δ-ferrite patches in weld fusion zone and heat affected zone (HAZ) of welded joints. The evolution of δ-ferrite patches was carried out in as-welded and post-weld heat treatment (PWHT) condition. PWHT was carried out at 760 °C for 2 h for both A-TIG and GTA welding process. For A-TIG weld joint higher yield strength, ultimate tensile strength (UTS) and peak hardness were measured due to higher heat input in single pass and higher carbon content in weld fusion zone. Higher heat input, fast cooling rate and higher weight percentage of ferrite stabilizer like vanadium (V) and niobium (Nb) in A-TIG weld joint were resulted in formation ferrite patches in weld fusion zone and heat affected zone. Higher weight percentage of V and Nb in A-TIG weld zone was resulted poor impact toughness of A-TIG weld fusion zone than GTA welds in as-welded condition. After the PWHT at 760 °C–2 h, Charpy toughness of A-TIG weld fusion zone (48 J) just meet the minimum required value as required by the EN: 1557:1997 (47 J).

Ferritic/martensitic 9Cr-1Mo-V-Nb (P91) and 9Cr-0.5Mo-1.8W-V-Nb (P92) steel are used for high temperature (600-650°C) operating components in nuclear and thermal power plants. The present research work deals with the dissimilar joining of P91 and P92 steel using autogenous tungsten inert gas (TIG) welding and multi-pass gas tungsten arc welding (GTAW) with filler. The evolution of δ-ferrite patches in weld fusion zone and heat affected zones (HAZs) were characterized in as-welded and post weld heat treatment (PWHT) condition. PWHT was carried out at 760 °C for 2 h and 6 h, for both autogenous-TIG and GTA weld joints. Charpy toughness and microhardness tests were performed for autogenous-TIG welding and GTA welding process under as-welded and PWHT condition.

Creep strength enhanced ferritic/martensitic 9Cr-1Mo-V-Nb (P91) steel is also designated as ASTM A335 used for out-of-core and in-core (piping, cladding, ducts, wrappers, and pressure vessel) of Gen IV reactors. In present investigation, the dissimilar weld joint of P91 and P92 steel were made using the autogenous tungsten inert gas (TIG) welding with single pass, double side pass and multi-pass gas tungsten arc (GTA) welding with filler wire. Microstructure evolution in sub-zones and mechanical properties of dissimilar welded joints were studied in as-welded and post weld heat treatment (PWHT) condition. Formation of δ-ferrite patches in weld fusion zone and heat affected zones (HAZs) and their influence on the mechanical behaviour of the welded joints were also studied. Presence of higher content of ferrite stabilizer in P92 steel have resulted the formation of δ-ferrite patches in weld fusion zone as well as HAZs. The δ-ferrite was observed in autogenous TIG welds joints. The δ-ferrite patches were formed in as-welded condition and remained in the microstructure after the PWHT. The δ-ferrite patches leads to reduction in Charpy toughness of autogenous TIG welds joint and also lower down the average hardness of weld fusion zone. Peak hardness and poor impact toughness were observed for autogenous TIG welds joint as compared to GTA welds. For microstructure characterization, field-emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS) and optical microscope were utilized.

Creep strength enhanced ferritic/martensitic P91 steel is considered as a candidate material for the reactor pressure vessels and reactor internals of Very High Temperature Reactor (VHTR). Heterogeneous microstructure formation across the P91 weldments lead to premature Type IV cracking and makes the weldability of P91 steel a serious issue. The present research work describes the effect of normalizing and tempering (N&T) treatment on microstructure evolution in various zones of gas tungsten arc welded (GTAW) P91 pipe weldments. For N&T treatment, P91 pipe weldments were subjected to various normalizing (950–1150 °C) and tempering (730–800 °C) temperature. The effect of varying heat treatment on tensile properties and hardness of P91 pipe weldments were studied for V-groove and narrow-groove weld designs. The effect of increase in normalizing temperature (fixed tempering temperature) resulted in increase in strength and hardness, while increase in tempering temperature (fixed normalizing temperature) resulted in the decrease in strength and hardness of P91 steel weldments. The better combination of strength, ductility and microstructure were obtained for the maximum normalizing temperature of 1050 °C and tempering temperature of 760 °C.

Creep strength enhanced ferritic (CSEF) P91 steel were subjected to room temperature tensile test for quasi-static (less than 10−1/s) strain rate by using the Instron Vertical Tensile Testing Machine. Effect of different type of notch geometry, notch depth and angle on mechanical properties were also considered for different strain rate. In quasi-static rates, the P91 steel showed a positive strain rate sensitivity. On the basis of tensile data, fracture toughness of P91 steel was also calculated numerically. For 1 mm notch depth (constant strain rate), notch strength and fracture toughness were found to be increased with increase in notch angle from 45° to 60° while the maximum value attained in U-type notch. Notch angle and notch depth has found a minute effect on P91 steel strength and fracture toughness. The fracture surface morphology was studied by field emission scanning electron microscopy (FESEM).

The grade P91 and P92 steel are commonly used materials for the components in ultra-supercritical power plants in the temperature range of 590–650 °C. For welded joints, the notch toughness and microstructure stability played an essential role in meeting the requirement of high temperature creep properties. The microstructural stability and notch toughness were strongly affected by the composition of base and filler materials, welding processes and pre and post-weld heat treatments (PWHTs). In the present research, four different combinations of similar/dissimilar welded joints of P91 and P92 steel are prepared using shielded metal arc welding (SMAW). The microstructure of different welded joints has been characterized in the as-welded condition. For the as-welded state, the room temperature tensile properties, flexural strength, microhardness and notch toughness have been studied. The δ-ferrite patches were observed for P92 filler welded joints. It has been concluded that in the weld fusion zone, the higher amount of ferrite stabilizers promotes the formation of the δ ferrite. The tensile strength and flexural strength were increased in P92 filler welds due to the presence of solid solution hardening elements in the P92 filler. The detrimental effect of δ-ferrite patches has been observed on the Charpy impact toughness and microhardness values of the weld fusion zone. The Charpy toughness values in the weld fusion zone were 12 ± 2, 7 ± 2, 8 ± 2 and 5 ± 3 J for P91-P91-P91, P92-P92-P92, P91-P91-P92 and P91-P92-P92 weld joints, respectively, which were lower than the minimum recommended Charpy toughness value (47 J) for ferritic steel welded joints.

The modified 9Cr-1Mo (P91) and 9Cr- 0.5Mo- 1.8W (P92) steel used in fast breeder reactor is exposed to irradiation during service which severely affects the dynamic fracture resistance by increasing the ductile to brittle transition temperature (DBTT). Thus, even at room temperature, the steel can become brittle and prone to cracking. In the present investigation, to elucidate the influence of low temperature on the DBTT, Charpy toughness test was performed on creep strength enhanced ferritic P91 and P92 steel. Lower DBTT was observed for the P92 steel as compared to P91 steel. To find the mode of fracture, the fractured Charpy toughness specimens were investigated using a field electron scanning electron microscope (FESEM). The fracture surface revealed the brittle mode of fracture at a lower temperature for both the steels while the mixed mode of fracture was noticed at room temperature and above.

In present research work, multi-pass friction stir processing was utilized for the as-cast Al–17%Si alloy. The multi-pass friction stir processing reproduced the aluminum (Al) matrix with a uniform distribution of the ultra-fine silicon (Si) particles. The multi-pass friction stir processing also resulted in the formation of refining cast microstructure with negligible porosity. The significant reduction in silicon particle size was measured and it reduced from 204 µm to 0.86 µm after the first pass and up to 0.30 µm after two pass friction stir processing. The frequency of fine Si particles was increased after two pass friction stir processing as compared to single pass friction stir processing. The engineering stress–strain curves revealed a significant enhancement in ductility and strength after one and two passes of friction stir processing as compared to the as-cast alloy. After one and two passes of friction stir processing, the ultimate tensile strength of as-cast alloy was enhanced by 24% and 31% and ductility was increased by 300% and 500%, respectively. The secondary electron micrograph of fracture surfaces of tensile specimens was taken before and after friction stir processing. The fractographs revealed the transformation from brittle mode to ductile dimples fracture after the multi-pass friction stir processing process.