Metallurgist, National Bureau of Standards, Washington, D.C.
Associate professor, George Washington University, Washington, D.C.
Pages: 12 Published: Jan 1978
Fracture toughness tests and fractographic examinations were conducted on temper embrittled and deembrittled 2¼Cr-1Mo steel using double cantilever-beam specimens. The tests were conducted in an aqueous/acetic acid solution containing hydrogen sulfide (H2S). The threshold stress intensity of the temper embrittled specimen tested in the H2S environment was lower than that of the deembrittled specimens tested in a similar environment. For the purpose of comparing fracture appearances, temper embrittled and deembrittled specimens were fractured in air.
The fracture appearances of the temper embrittled and the deembrittled specimens tested in the H2S environment and the temper embrittled specimen fractured in air were predominantly intergranular. The fracture appearance of the deembrittled specimen fractured in air exhibited a transgranular ductile mode of failure. These results indicate that the embrittling effects due to temper embrittlement and to the H2S environment act cooperatively in reducing the threshold stress intensity of 2 ¼ Cr-1Mo steel.
steels, temper embrittlement, hydrogen embrittlement, fracture properties, fractography
Paper ID: STP38100S