淬火终冷温度对DQ钢组织和力学性能的影响  

Effects of Quenching Termination Temperature on Microstructure and Mechanical Properties of DQ Steel

作　　者：杨雄 余伟[1] 唐荻[1] 吕德文 王会岭 范佳 YANG Xiong;YU Wei;TANG Di;LYU Dewen;WANG Huiling;FAN Jia(Metallurgical Engineering Research Institute,University of Science and Technology Beijing,Beijing 100083,China;Technology Center,He Steel Limited Company Handan Branch,Handan 056015,China)

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083 [2]河钢集团邯钢分公司技术中心,河北邯郸056015

出　　处：《热加工工艺》2019年第20期125-129,共5页Hot Working Technology

基　　金：长江学者和创新团队发展计划资助项目(IRT1234)

摘　　要：为了采用DQ(直接淬火)工艺开发960 MPa强度级别的超高强钢,测量了Q960D高强钢的动态CCT曲线,并研究了DQ工艺中淬火终冷温度对该高强钢组织和力学性能的影响。结果显示,当冷却速度在1~3℃/s时,淬火冷却过程中高强钢发生B和M相变。随着冷却速度升高至10℃/s时,组织仅发生M相变,Bs和Ms分别为520和440℃。当冷却速度在20℃/s、淬火终冷温度在100~300℃时,高强钢组织主要为M,抗拉强度在1390~1450 MPa,屈服强度为1050~1150 MPa,伸长率为9%~10%,-20℃冲击功为33.1~56.0 J;当淬火终冷温度为400~520℃时,高强钢组织主要为粒状B,抗拉强度为992~1001 MPa,屈服强度为705~752 MPa,伸长率为10.8%~16.8%,-20℃冲击功为16~19 J。In order to develop super high strength steel with 960 MPa strength grade by DQ(direct quenching) process,the dynamic CCT curve of Q960 D high strength steel was measured. The effects of quenching termination temperature in DQ process on the microstructure and mechanical properties of the high strength steel were also studied. The results show that,when the cooling rate is 1-3 ℃/s, the B and M phase transformation of the high strength steel occurs during quenching. With the increase of cooling rate to 10 ℃/s, only M phase transition occurs in the microstructure. Bsand Msare 520 ℃ and 440 ℃,respectively. When the cooling rate is 20 ℃/s and the quenching termination temperature is 100-300 ℃, the microstructure of high strength steel is mainly M, the tensile strength is 1390-1450 MPa, the yield strength is 1050-1150 MPa, the elongation is9%-10%, and the impact work at-20 ℃ is 33.1-56.0 J. When the quenching termination temperature is 400-520 ℃, the microstructure of the high strength steel is mainly granular B, the tensile strength is 992-1001 MPa, the yield strength is 705-752 MPa, the elongation is 10.8%-16.8%, and the impact work at-20 ℃ is 16-19 J.

关 键 词：高强钢 动态CCT曲线 淬火终冷温度 

分 类 号：TG156.31[金属学及工艺—热处理]