Hydrogen-Induced Cleavage Fracture of Type 304L Austenitic Stainless Steel

摘要

Type 304L stainless steel supersaturated with hydrogen gas fails in tension at 200 to 250 exp 0 K by brittle fracture. Fracture surfaces exhibit isolated facets oriented 0 to 30 exp 0 to the tensile axis and have characteristics of cleavage fracture. The threefold symmetry of Laue back reflection photographs and trace analysis of deformation bands on the facets demonstrate that cleavage is along (111) planes. The fracture paths were identified as coherent twin boundaries on polished sections through facets and on microcracks across interior grains. Although cleavage fracture is not commonly observed in alloys with a face-centered cubic (FCC) lattice, these observations for Type 304L stainless steel and similar observations on Nitronic-40 and Tenelon demonstrate that cleavage is possible under some circumstances in austenitic steels. (ERA citation 05:001383)