摘要
The method of high-pressure hydrogen charging was used to investigate the internal hydrogen effects on cryogenic mechanical properties of two Cr-Ni-Mn-N austenitic steels, 22-13-5 and 21-6-9. Specimens saturated with hydrogen up to 65 multiplied by 10** minus **6-68 multiplied by 10** minus **6 were tested in air at temperatures ranging from 77 to 293 K. Hydrogen causes the increases in cryogenic strength, both yield strength and ultimate tensile strength. Hydrogen decreases cryogenic ductility, and the maximum hydrogen embrittlement tendency was found at a certain low temperature. Cr-Ni-Mn-N austenitic steels show the feature: delta //L greater than phi //L at low temperatures, here, delta //L and phi //L are the hydrogen induced loss rates of elongation and reduction of area, respectively. Hydrogen has less effect on cryogenic Charpy impact toughness and notched tensile strength, however, hydrogen decreases cryogenic fracture toughness of the steels. At temperature below M//d, the fracture toughness is obviously decreased due to the formation of strain-induced marten-sites, whether hydrogen is charged or not. (Edited author abstract) 7 Refs.
The method of high-pressure hydrogen charging was used to investigate the internal hydrogen effects on cryogenic mechanical properties of two Cr-Ni-Mn-N austenitic steels, 22-13-5 and 21-6-9. Specimens saturated with hydrogen up to 65 multiplied by 10** minus **6-68 multiplied by 10** minus **6 were tested in air at temperatures ranging from 77 to 293 K. Hydrogen causes the increases in cryogenic strength, both yield strength and ultimate tensile strength. Hydrogen decreases cryogenic ductility, and the maximum hydrogen embrittlement tendency was found at a certain low temperature. Cr-Ni-Mn-N austenitic steels show the feature: delta //L greater than phi //L at low temperatures, here, delta //L and phi //L are the hydrogen induced loss rates of elongation and reduction of area, respectively. Hydrogen has less effect on cryogenic Charpy impact toughness and notched tensile strength, however, hydrogen decreases cryogenic fracture toughness of the steels. At temperature below M//d, the fracture toughness is obviously decreased due to the formation of strain-induced marten-sites, whether hydrogen is charged or not. (Edited author abstract) 7 Refs.
