The susceptibility of multipass flux-cored arc welds of STSs 308 L and 316 L to hydrogen embrittlement (HE) was investigated at various temperatures. Cracks predominantly initiated and propagated along the δ-ferrite in the interdendritic region at 25 °C. δ-ferrite served as preferred hydrogen trap sites, and the δ/γ boundary became the stress concentration site. At −100 °C, STSs 308 L and 316 L exhibited high susceptibility to HE owing to strain-induced martensite formation, providing additional hydrogen trap sites and dislocation accumulation. Despite strain-induced martensite actively transformed at −196 °C, the HE disappeared owing to the sluggish diffusion of hydrogen to stress-concentrated areas.

中文翻译：

---

δ-铁素体和应变诱导马氏体对 STS 308 L 和 STS 316 L 全焊缝金属氢脆的影响

在不同温度下研究了 STS 308 L 和 316 L 多道药芯焊丝电弧焊对氢脆 (HE) 的敏感性。 25 °C 时，裂纹主要沿着枝晶间区域的 δ 铁素体引发和扩展。 δ-铁素体是优选的氢陷阱位点，δ/γ边界成为应力集中位点。在-100 °C 时，STS 308 L 和 316 L 由于应变诱导马氏体形成而表现出对 HE 的高敏感性，提供了额外的氢陷阱位点和位错积累。尽管应变诱导马氏体在-196°C 时发生积极转变，但由于氢向应力集中区域的缓慢扩散，HE 消失了。