High Strength-Ductility Nb-microalloyed Low Martensitic Carbon Steel:Novel Process and Mechanism  

作　　者：Ke Zhang Ping Liu Wei Li Zheng-Hong Guo Yong-Hua Rong 

机构地区：[1]School of Materials Science and Engineering, University of Shanghai for Science and Technology [2]School of Materials Science and Engineering, Shanghai Jiao Tong University

出　　处：《Acta Metallurgica Sinica(English Letters)》2015年第10期1264-1271,共8页金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51301106)

摘　　要：A low-carbon Nb-microalloyed Fe-Mn-Si-based steel was treated by a novel quenching-partitioning-tempering（Q-P-T） process as a modified quenching and partitioning（Q＆P） process. After processed by Q-P-T treatment,this steel exhibits excellent mechanical properties such as high product of strength and elongation. The addition of Nb markedly raises both the yield strength and tensile strength of Q-P-T martensitic steel, especially the yield strength, which can be attributed to the strong grain refinement strengthening and precipitation strengthening of Nb. The Nb addition can also lead to a little increase in ductility. The Nb-microalloyed steel treated by Q-P-T process displays much higher ductility than that treated by traditional quenching and tempering（Q＆T） process. The mechanisms of Q-P-T process on ductility enhancement were fully analyzed and can be attributed to high quenching temperature and considerable amount of retained austenite.A low-carbon Nb-microalloyed Fe-Mn-Si-based steel was treated by a novel quenching-partitioning-tempering（Q-P-T） process as a modified quenching and partitioning（Q＆P） process. After processed by Q-P-T treatment,this steel exhibits excellent mechanical properties such as high product of strength and elongation. The addition of Nb markedly raises both the yield strength and tensile strength of Q-P-T martensitic steel, especially the yield strength, which can be attributed to the strong grain refinement strengthening and precipitation strengthening of Nb. The Nb addition can also lead to a little increase in ductility. The Nb-microalloyed steel treated by Q-P-T process displays much higher ductility than that treated by traditional quenching and tempering（Q＆T） process. The mechanisms of Q-P-T process on ductility enhancement were fully analyzed and can be attributed to high quenching temperature and considerable amount of retained austenite.

关 键 词：Heat treatment Mechanical properties Microstructure Microalloyed steel MARTENSITICTRANSFORMATION 

分 类 号：TG161[金属学及工艺—热处理]