Effect of aging precipitation on the stress corrosion cracking behavior of Ni(Fe, Al)-maraging steel
作者
单位
1 Collaborative Innovation Center for Advanced Steels & Joint International Research Laboratory of Refractories、Wuhan University of Science and Technology、Wuhan 430081、P. R. China 2 School of Materials Science and Engineering、Ocean University of China、Qingdao 266100、P. R. China 3 Shandong Iron and Steel Co. Ltd、Jinan 271104、P. R. China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
The effect of aging precipitation on the stress corrosion crac king (SCC) mechanism of Ni(Fe, Al) -maraging steel was studied through comparative characterizations and analyses on microstructures and fracture features of the solid - solution and peak -aged steels. Aging precipitation brings a chain of impacts on the deformative compatibility and electrochemical difference between the matrix and other phases or interfaces. The strength of the martensite matrix is enhanced by the abundant and evenly dispersed Ni(Fe, Al) precipitate, thereby reducing the possibility of splitt ing across the martensite laths. Meanwhile, the Volta potential difference between the matrix and the primary NbC particles is increased from 11.3mV to 18.60mV. Since most of the primary NbC particles tend to be distributed along high - angle grain boundaries (HAGBs), the anodic dissolution along HAGBs is accelerated. Therefore, both the mechanical and electrochemical factors, triggered by aging precipitation, are involved in the variation of SCC behavior and mechanism. The SCC susceptibility of the steel is increased along with the increasing tendency of intergranular cracking.