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The prediction of steel thermophysical properties are special interest for thermal engineering applications. This work aims to obtaining a method for predicting the temperature influence and composition on the variation on the austenitic stainless steels thermophysical properties. Applying the Flash Laser method, 3 255 experimental samples for rolled and annealed AISI steels (301, 302, 304, 310 and 316) was obtained, which summarize the variation of thermal conductivity, specific heat, diffusivity and density, for known compositions (in mass percent) of C, Mn, P, S, Si, Ni, Cr, Mo, V, in a temperature range from 0 to 800?. By means machine learning techniques, the available experimental data were generalized, developing a correlation that fits the experiments validity range, with a deviation of 25% for the 90% of the available experimental data. In all cases, the agreement for the proposed model is good enough to be considered satisfactory for practical design. [ABSTRACT FROM AUTHOR]

The evaluation of diffusible hydrogen is critical in determining the quality and strength of UnderWater Wet Welding joints. The objective of this study was to separately evaluate the influence of four fundamental variables on the amount of diffusible hydrogen in underwater welding: welding depth, polarity, current and electrode specification. Applying a full two-level factorial design to these four factors. Statistical analysis allowed us to establish the relevance of the variation of each factor on the diffusible hydrogen content of the welds. Austenitic stainless steel electrodes were used. The lowest Diffusible Hydrogen values were obtained at higher depth and welding current levels, with positive polarity, and electrode E312 in detriment to E309. In this study, the factorl with the greatest impact on Diffusible Hydrogen was the Welding Depth. [ABSTRACT FROM AUTHOR]

Copyright of Investigación e Innovación en Ingenierías is the property of Universidad Simon Bolivar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingenius, Revista Ciencia y Tecnología is the property of Universidad Politecnica Salesiana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Austenitic stainless steels are widely used in many industrial fields, mainly due to their good corrosion resistance; however, their low hardness and poor wear resistance limit their applications. Among different methods of surface hardening, the plasma or ion nitriding technique has also proven to be effective in preserving their corrosion resistance. When austenitic stainless steels such as AISI 316L are nitrided at low temperature, i.e. below 420 °C, an expanded austenite phase free of nitrides is formed, called "S" phase. This phase is a diffusion layer, it is wear and corrosion resistant but there is still a great discussion about its nature. In this work, the structure of the modified layers in AISI 316L nitrided in a pulsed DC discharge were characterized by SEM, SIMS, normal incidence and grazing angle XRD with a Synchrotron source and TEM, for which the sample was prepared with FIB. The nitrogen expanded austenite layer was 4,5 μm thick with a nitrogen content of 27 at% and the calculated expansion of the lattice was about 6,5 %. A second carbon expanded austenite layer, could be observed below the nitrogen expanded phase. With GI XRD, no Cr or Fe nitrides were detected, only the S-phase with broader peaks than the original of the base material and shifted to lower angles, showing not only a lattice expansion but also a stressed layer with defects. In fact, the layer presented a large plastic deformation, since twins were observed in the dark field of the TEM image. Chromium nitrides reflections were also detected. [ABSTRACT FROM AUTHOR]

The research shows the characterization of mechanical properties in dissimilar steel welded unions: a structural steel (ASTM A537/A537M:95) butt welded with austenitic stainless steel 304L (ASTM A240/A240M:01) through semiautomatic electrical arc welding process protected by inert gas (GMAW); Argon was used as a protecting gas and austenitic stainless steel ER308L as a supplier material (ANSI/AWS A5.9/A5.9M:2006). Samples were tested in unwelded conditions to characterize the materials involved in the investigation, and they were also tested in welded conditions, not being submitted to pre and post welding thermal treatment. Welded-based material samples were characterized through optical microscopy (OM), an inspection of nondestructive testing (NDT) with penetrating liquids and ultrasound were also conducted. The following mechanical tests were completed, not only on the base metals but on the welding as well: Vickers micro hardness profile, traction, Charpy impact, bending test (face and root), and axial fatigue. Results showed a proper mechanical steel behavior, welded by GMAW procedure, under monotonic and cyclic loads, in spite of they showed high values of micro hardness in the heat affected zone (HAZ), mainly in the proximity of the fusion line between the welding cord and the stainless steel 304L, as well as inclusions between the structural steel and the stainless one. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stainless steel samples with 100% austenitic microstructure and alloyed with 0.9 wt-% of nitrogen in solid solution were tested under vibratory cavitation experiments in distilled water to study the cavitation-erosion wear (EC) at grain size level (mesoscale). Fully austenitic samples were obtained by high temperature gas nitriding (HTGN) a commercially available dúplex stainless steel, UNS S31803. The samples were characterized by electron backscattering diffraction, EBSD to obtain the crystalline orientation of individual grains. In addition, mass loss measurements were obtained and surface damage evolution was analyzed by scanning electron microscopy (SEM) at different times of the test. These results were analyzed as a function of the prior crystallographic characterization. For comparison, a conventional austenitic stainless steel, UNS S30403, was also investigated. It was observed that both the nucleation and the growth of damage are heterogeneous at the grain-size scale due to mesoscale plasticity an isotropy, induced during the CE tests. The heterogeneous character of the cavitation damage is related to both the grain boundary character and the microtexture inside the grains. [ABSTRACT FROM AUTHOR]