Impact of heat treatment on the mechanical properties of AISI 304L austenitic stainless steel in high-pressure hydrogen gas

Abstract

Hydrogen environment embrittlement of metastable austenitic stainless steels is a well-known phenomenon partially related to the formation of straininduced martensite. In the literature, hydrogen environment embrittlement is often discussed on the basis of nominal chemical compositions only and neglects effects of metallurgical production and processing. The aim of this study is to investigate the influence of the d-ferrite volume fraction and grain size on the mechanical properties of a standard grade 1.4307 (AISI 304L) tested in high-pressure hydrogen gas. A negligible influence was found for dferrite volume fractions between 2 and 10 %. This result is explained by the dominating influence of machininginduced a-martensite on the surface of the tensile samples. In contrast, the grain size was found to have a significant effect on hydrogen environment embrittlement. In particular, grain sizes smaller than 50 lm were found to have a higher ductility. The results are discussed with respect to stacking fault energy, formation of strain-induced a-martensite, trapping of hydrogen and microsegregations. The results are of particular interest for the materials selection and development of materials for hydrogen applications.

Critical grain size to limit the hydrogen-induced ductility drop in a metastable austenitic steel

“…The increasing appearance of brittle fracture features with increasing grain size (Fig. 5) is in accordance with the above-mentioned studies [10,13,17] where ductile features were present in smaller grains and absent in larger grains. It was shown previously [25], through the analysis of Kernel Average Misorientation maps obtained with EBSD, that strain from low strain in green to high strain in red) and Image Quality maps of ultra-fine grained and coarse grained Fe-16Cr-10Ni with solute hydrogen for ε ¼ 0.36 [15].…”

“…More recently, other teams used hydrogen gas charging to introduce hydrogen into austenitic stainless steels. Weber et al [10] studied AISI 304L with grain sizes ranging from 130 down to 13 mm in 40 MPa hydrogen gas at room temperature. The ductility was increasingly reduced by hydrogen for increasing grain sizes.…”

Effect of heat treatment on the blast loading response of combined geometry shell core sandwich structures

“…The annealing time strongly depends on the amount of plastic deformation induced during deep-drawing. Comparable results were also reported for a similar material by Weber et al [31]. The pictures of the prepared small and big radius as-received and heat-treated combined shells and the geometrical parameters of the samples tested are shown in Fig.…”

Influence of Size on the Microstructure and Mechanical Properties of an AISI 304L Stainless Steel—A Comparison between Bulk and Fibers

“…Within the 300-series austenitic stainless steels, the 304 grade is the most commonly used due to its superior low temperature toughness, as well as its corrosion resistance [ 3 ]. Recently there has been an enormous amount of research addressing the improvement of the mechanical properties of austenitic stainless steel [ 4 , 5 , 6 , 7 , 8 ] without lowering corrosion resistance [ 9 , 10 , 11 , 12 ]. Many experimental studies have focused on AISI 304 and AISI 304L at elevated temperatures [ 13 , 14 , 15 ], under thermo-mechanical and cycle fatigue conditions [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ], under creep conditions [ 23 ] and ductility loss of hydrogen-charged steel [ 24 ].…”