Simultaneous increase of ultimate tensile strength and uniform elongation of 30Si2MnCrMoVE ultra-high strength steel by hot deformation direct quenching and partitioning

Journal of Materials Research and Technology

Yanhui Yang¹  Haiping Wang²  Dong Liu²  Jungang Nan²  Jianguo Wang³  Hai Wang³  Nan Lv³ 

[1] Chongqing Innovation Center of Northwestern Polytechnical University, Chongqing 401120, China;National Innovation Center of Defense Industry for Precise Forging and RingRolling, Xi'an 710072, Shaanxi, China;School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, China;

关键词: 30Si2MnCrMoVE ultra-high strength steel (UHSS);    Thermomechanical treatment;    Microstructure evolution;    Mechanical properties;   

DOI  :  

来源: DOAJ

【 摘 要 】

In order to further improve the combination of strength and ductility for 30Si2MnCrMoVE ultra-high strength steel (UHSS), a thermomechanical treatment, named deformation direct quenching and partitioning (DQ&P), was carried out on it. The microstructure evolutions and mechanical properties of 30Si2MnCrMoVE UHSS treated by DQ&P were compared with those treated by conventional off-line quenching and tempering (Q&T) through various microscopic characterization methods and uniaxial tensile tests. Moreover, the effects of austempering temperature on the microstructure evolutions and mechanical properties of the studied steel after DQ&P process were also investigated. The results show that the DQ&P samples, although lower or slightly lower yield strength, possess significantly higher ultimate tensile strength due to higher work-hardening rate caused by high density dislocations and fine dispersed carbides. Moreover, DQ&P310 sample exhibit apparently higher uniform elongation than Q&T sample despite of comparable content of retained austenite due to more prone to transformation induced plasticity (TRIP) effect. The DQ&P process can increase the ultimate tensile strength by 267 MPã423 MPa and the uniform elongation by 78%∼85%, respectively, as compared to Q&T process, which indicates that DQ&P process may be a promising thermomechanical treatment method to improve the comprehensive mechanical properties of the studied steel. The strengths and elongations of DQ&P samples do not vary monotonously with the increase of austempering temperature, which are both closely related to the content of retained austenite.

【 授权许可】

Unknown