Development of Ti–V–Mo Complex Microalloyed Hot-Rolled 900-MPa-Grade High-Strength Steel  

作　　者：Ke Zhang Zhao-Dong Li Xin-Jun Sun Qi-Long Yong Jun-Wei Yang Yuan-Mei Li Pei-Lin Zhao 

机构地区：[1]Department of Materials Science and Engineering, Kunming University of Science and Technology [2]Central Iron and Steel Research Institute [3]Department of Materials Science and Engineering, Huazhong University of Science and Technology [4]R&D Center, Laiwu Iron and Steel Group Co Ltd

出　　处：《Acta Metallurgica Sinica(English Letters)》2015年第5期641-648,共8页金属学报（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2010CB630805);the National Natural Science Foundation of China(No.51201036);China Iron&Steel Research Institute Group(No.12060840A)

摘　　要：A new Ti-V-Mo complex microalloyed hot-rolled high-strength steel sheet was developed by controlling a thermo-mechanical controlled processing （TMCP） schedule, in particular with variants in coiling temperature. The effects of coiling temperature （CT） on various hardening mechanisms and mechanical properties of Ti-V-Mo complex mi- croalloyed high-strength low-alloy steels were investigated. The results revealed that the steels are mainly strengthened by a combined effect of ferrite grain refinement hardening and precipitation hardening. The variation in simulated coiling temperature causes a significant difference in strength, which is mainly attributed to different precipitation hardening increment contributions. When the CT is 600 ℃, the experimental steel has the best mechanical properties： ultimate tensile strength （UTS） 1000 MPa, yield strength （YS） 955 MPa and elongation （EL） 17%. Moreover, about 82 wt% of the total precipitates are nano-sized carbide particles with diameter of 1-10 nm, which is randomly dispersed in the ferrite matrix. The nano-sized carbide particles led to a strong precipitation hardening increment up to 310 MPa.A new Ti-V-Mo complex microalloyed hot-rolled high-strength steel sheet was developed by controlling a thermo-mechanical controlled processing （TMCP） schedule, in particular with variants in coiling temperature. The effects of coiling temperature （CT） on various hardening mechanisms and mechanical properties of Ti-V-Mo complex mi- croalloyed high-strength low-alloy steels were investigated. The results revealed that the steels are mainly strengthened by a combined effect of ferrite grain refinement hardening and precipitation hardening. The variation in simulated coiling temperature causes a significant difference in strength, which is mainly attributed to different precipitation hardening increment contributions. When the CT is 600 ℃, the experimental steel has the best mechanical properties： ultimate tensile strength （UTS） 1000 MPa, yield strength （YS） 955 MPa and elongation （EL） 17%. Moreover, about 82 wt% of the total precipitates are nano-sized carbide particles with diameter of 1-10 nm, which is randomly dispersed in the ferrite matrix. The nano-sized carbide particles led to a strong precipitation hardening increment up to 310 MPa.

关 键 词：Hot-rolled high-strength steel Strengthening mechanism Nano-sized carbide Precipitationhardening Coiling temperature 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG335[金属学及工艺—金属材料]