INFLUENCE OF STRESS - INDUCED MARTENSITE ON SCC OF SUS 304 IN H_2SO_4 -NaCl AQUEOUS SOLUTIONS

摘要

Preferential dissolution was observed along many parallel slip bands inside the grain of the specimen with 30 % martensite specimen, which differs significantly from the cracking appearance of a single austenitic specimen. The weight loss of an 86 % martensite specimen was larger than that of an austenitic specimen. The dissolution rate of 86 % martensitic specimen was 14.6 times larger than that of a single austenitic specimen in 2.5 kmol/m~3 H_2SO_4 solution with 0.2 kmol/m~3 NaCl when stress corrosion cracking (SCC) propagated at the maximum rate. This dissolution rate difference was observed to be only 2.6 times greater in 2.5 kmol/m~3 H_2SO_4 solution with 0.5 kmol/m~3 NaCl in which no SCC initiated.