AUSTENITE STAINLESS STEEL FOR USE IN ENVIRONMENT OF HIGH TEMPERATURE AND LOW CHLORINE CONCENTRATION

摘要

PURPOSE:To enhance resistance to stress corrosion cracking as well as mechanical strength under high-temperature low-concentration chlorine water contact condition by controlling the content of N is austenite stainless steel and by adding alloy elements such as Ti, Nb, Ta, V, etc. CONSTITUTION:As construction material for chemical industry or nuclear industry where the material contacts high-purity water with chlorine less than 10ppm at 100 deg.C or more, austenite stainless steel havisng the following composition is used. C0.03%, Si2%, Mn4%, Cr: 16-20%, Ni: 8-16%, Mo: 2-3%, N:0.04- 0.30%, and 0.1-1% of one or more of Ti, Nb, V, Ta, and Zr. N is effective for increasing strength in high-temperature chlorine water, but adversely affects stress corrosion cracking, and therefore its content is limited to less than 0.3%. Ti, Nb, etc. reacts with N to form nitride, and its effects of precipitation hardening and fine crystal grain formation enhance mechanical strength.