Investigation of stress corrosion cracking behavior and mechanism analysis of a 1900 MPa-grade ultra-high-strength stainless steel  

作　　者：Shuai Tian Zhen-bao Liu Ren-li Fu Xiao-hui Wang Jian-xiong Liang 

机构地区：[1]School of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,Jiangsu,China [2]Instiute for Special Steel Institute,Central Iron and Steel Research Institute,Beijing 100081,China

出　　处：《Journal of Iron and Steel Research International》2022年第9期1474-1484,共11页

基　　金：support from the National Key Research and Development Program of China(2016YFB0300104).

摘　　要：The stress corrosion cracking(SCC)behavior of a 1900 MPa-grade ultra-high-strength stainless steel in 3.5 wt.% NaCl solution was investigated by X-ray diffractometer,scanning electron microscopy,electron back-scattered diffraction,X-ray photoelectron spectroscopy,and potentiodynamic polarization curves.The results showed that USS122G stel has good SCC resistance,and the critical stress intensiy factor(K_(iscc))of USS122G steel was about 68.906 MPa m^(1/2) and Kiscc/K_(ic)=0.76(K_(ic) is plane strain fracture toughness).The existence of film-like austenite along the lath martensite boundary and the protective effect of thecc passivation flm were the main factors for its high Kiscc.Among them,the main components of the passivation film on the surface of USS122G steel were Cr_(2)O_(3),Cr(OH)_(3),FeOOH,and Ni(OH)_(2).The fracture morphology of SCC zone was intergranular and transgranular.Through the slow and fast scanning rate polarization curve test results,it can be concluded that SCC mechanism of USS122G steel in 3.5 wt.%NaCl solution at the open-circuit potential was a mixed mechanism involving hydrogen embritlement and anodic dissolution.

关 键 词：Ultra-high-strength stainless steel.Critical stress intensity factor-Film-like austenite Hydrogen embrittlement Anodic dissolution 

分 类 号：TG142.71[一般工业技术—材料科学与工程]