低温回火对低碳马氏体超高强钢组织及力学性能的影响  

Effect of Low⁃Temperature Tempering on Microstructure and Mechanical Properties of Low⁃Carbon Martenstic Ultra⁃High Strength Steel

作　　者：史术华 高擎 钱亚军 SHI Shuhua;GAO Qing;QIAN Yajun(Xiangtan Iron&Steel Group Co Ltd,Xiangtan 411101,Hunan,China)

机构地区：[1]湘潭钢铁集团有限公司,湖南湘潭411101

出　　处：《矿冶工程》2023年第6期174-178,共5页Mining and Metallurgical Engineering

基　　金：长株潭国家自主创新示范区专项(2018XK2301)。

摘　　要：研究了低温回火对经过正火+淬火处理的Q1100超高强钢显微组织与力学性能的影响。结果表明,经正火(890℃×40 min)+淬火(890℃×30 min)+回火(185~320℃×90 min)处理的实验钢主要获得回火马氏体组织。不同温度回火后,实验钢抗拉强度均大于1360 MPa、屈服强度均大于1200 MPa、硬度均大于400HV3、延伸率均大于13%、-40℃冲击功均大于35.0 J。随着回火温度升高,实验钢抗拉强度逐渐下降,屈服强度先上升后下降,硬度逐渐降低,断后延伸率先略微下降后逐渐上升,-40℃冲击功先下降后上升。回火温度230℃时,实验钢抗拉强度(1445 MPa)、屈服强度(1238 MPa)、硬度(429HV3)、塑性(13.8%)和-40℃冲击韧性(47.5 J)均表现优异,大幅超过Q1100级工程机械用超高强钢的服役标准。The effects of low temperature tempering on the microstructure and mechanical properties of Q1100 ultra⁃high strength steel after pretreatment of normalizing and quenching were studied.The results show that tempered martensite were obtained after normalizing(890℃×40 min)+quenching(890℃×30 min)+tempering(185-320℃×90 min)processes.After tempering at different temperatures,all tested steels have their tensile strength higher than 1360 MPa,yield strength higher than 1200 MPa,hardness higher than 400HV3,elongation higher than 13%,and impact energy at-40℃higher than 35.2 J.With the rising of tempering temperature,the tensile strength and hardness gradually decrease,the yield strength first increases and then decreases,the elongation after fracturing increases after an initial slight decrease,and the impact energy at-40℃decreases followed by increase.At a tempering temperature of 230℃,the steel in the test has tensile strength of 1445 MPa,yield strength of 1238 MPa,hardness of 429HV3,plasticity of 13.8%,and toughness of 47.5 J,which all largely exceed the service standard of Q1100 ultra⁃high strength steel for construction machinery.

关 键 词：回火 Q1100 超高强钢 马氏体 强度 韧性 冲击功 

分 类 号：TG142.1[一般工业技术—材料科学与工程]