Automobile Technology & Material
Si Yu1, Tang Yuanshou1, Zhou Xin1, Li Kejian1, Ma Yilong1, Ma Mingtu2
Research Progress of Microalloy Elements on Hydrogen-induced Delayed Cracking in High Strength Martensitic Steels
（1. School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331;
2. China Automotive Engineering Research Institute Co., Chongqing, 401122） Abstract：the development of high strength martensitic steels can control the precipitation of C, N and other nano compounds by optimizing the composition design of micro alloy and matching reasonable heat treatment, and form a benign“hydrogen trap”, thus reducing the risk of delayed cracking caused by hydrogen in the process of application. This paper compared the precipitation forms and hydrogen trapping sites of Ti, Nb and Cu alloy elements in martensitic steels under different heat treatment processes, and evaluated the hydrogen trapping ability of precipitated phases in high strength martensitic steels. The results show that the hydrogen capture capacity is ranked as follows: NBC> TIC> grain boundary>ε-cu> dislocation, and the compound addition of microalloying elements can play a better anti-hydrogen embrittlement effect.