Microstructure and Properties of a Low Carbon Ti-V Microalloyed Steel
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2018年第6期
论文作者：裴新华 LIU Zhenyu WEI Jiao LIU Xuefeng 贾涛 HU Hengfa
文章页码：1491 - 1495
摘 要：Due to the largely inhomogeneous deformation among constituent phases, the advanced high-strength multi-phase steels are always facing challenges when applied to automotive parts where local formability is critically required. In this work, two characteristic microstructures were produced from a low carbon Ti-V microalloyed steel by varying the cooling path. In the ferrite single-phase microstructure resulted from "ultra-fast cooling（UFC） + furnace-cooling（FC）", the hole-expanding ratio of 200% and tensile strength of 647 MPa were achieved. In the ferrite-bainite-martensite（F+B+M） multi-phase microstructure produced by "UFC + air-cooling（AC） + UFC", the ferrite has been strengthened by Ti-V carbides to promote the strain partitioning, which resulted in the tensile strength of ≥780 MPa, a moderate elongation and hole-expanding ratio of 93%. The strengthening contributions of Ti-V carbides were calculated to be 126 MPa and 149 MPa in the ferrite single-phase and F+B+M multi-phase microstructure, respectively.
裴新华1,2，LIU Zhenyu1，WEI Jiao3，LIU Xuefeng1，贾涛1，HU Hengfa2
1. The State Key Lab of Rolling & Automation, Northeastern University2. Meishan Iron & Steel Co., Ltd3. BaoSteel Co., Ltd
摘 要：Due to the largely inhomogeneous deformation among constituent phases, the advanced high-strength multi-phase steels are always facing challenges when applied to automotive parts where local formability is critically required. In this work, two characteristic microstructures were produced from a low carbon Ti-V microalloyed steel by varying the cooling path. In the ferrite single-phase microstructure resulted from "ultra-fast cooling（UFC） + furnace-cooling（FC）", the hole-expanding ratio of 200% and tensile strength of 647 MPa were achieved. In the ferrite-bainite-martensite（F+B+M） multi-phase microstructure produced by "UFC + air-cooling（AC） + UFC", the ferrite has been strengthened by Ti-V carbides to promote the strain partitioning, which resulted in the tensile strength of ≥780 MPa, a moderate elongation and hole-expanding ratio of 93%. The strengthening contributions of Ti-V carbides were calculated to be 126 MPa and 149 MPa in the ferrite single-phase and F+B+M multi-phase microstructure, respectively.
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