热成形加热速率对22MnB5钢组织和性能的影响  

EFFECT OF HOT FORMING HEATING RATE ON MICROSTRUCTURE AND PROPERTIES OF 22MnB5 STEEL

作　　者：王学慧 花福安[2] 周泽宇 孙中华 罗扬 冯小雷 Wang Xuehui;Hua Fuan;Zhou Zeyu;Sun Zhonghua;Luo Yang;Feng Xiaolei(HBIS Materials Technology Research Institute,Shijiazhuang 050023,Hebei;State Key Laboratory of Rolling Technology and Continuous Rolling Automation,Northeastern University,Shenyang 110819,Liaoning)

机构地区：[1]河钢材料技术研究院,河北石家庄050023 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《河北冶金》2023年第10期25-29,共5页Hebei Metallurgy

摘　　要：22MnB5是常见的热成形高强钢,广泛应用于汽车车身,可减轻车身质量,提高汽车抗冲击和防温性。随着用户对热成形零件生产效率要求的不断提高,特别是感应力加热,火焰直燃加热等快速加热技术的推广应用,热减形加热速率快速提升到120℃/s。为了考察不同加热速率对22MnB5钢热成形后的组织和性能的影响规律,利用淬火膨胀仪、扫描电子显微镜(SEM)和拉伸试验机,分别对加热冷却过程中的热膨胀曲线、热成形后的微观组织和力学性能进行了测定。结果表明,随加热温度升高,试样冷却组织由铁素体向马氏体、贝氏体转变,且150℃/s加热速率下组织中贝氏体和铁素体含量要高于10℃/s加热速率的试样;且当加热速率从10℃/s提高到150℃/s时,22MnB5钢在950℃仍然能够完全奥氏体化,但是冷却试样的条件屈服强度、抗拉强度、断后伸长率都有所下降,分别降低了334 MPa、56 MPa、0.9%。22MnB5 is a common hot-stamping high-strength steel,which is widely used in automobile body,which can reduce body mass and improve automobile impact resistance and temperature resistance.With the continuous improvement of users'requirements for the production efficiency of hot stamped parts,especially the promotion and application of rapid heating technologies such as induction heating and flame direct combustion heating,the heating rate of thermal reduction has rapidly increased to 120℃/s.To investigate the influence of different heating rates on the microstructure and properties of 22MnB5 steel after hot forming,the thermal expansion curve,microstructure and mechanical properties after hot forming were measured by quenching expander,scanning electron microscope(SEM)and tensile testing machine.The results showed that with the increase of heating temperature,the cooling tissue of the sample changed from ferrite to martensite and bainite,and the content of bainite and ferrite in the tissue at a heating rate of 150℃/s was higher than that of the specimen with a heating rate of 10℃/s.And when the heating rate is increased from 10℃/s to 150℃/s,22MnB5 steel can still be completely austenitized at 950℃,but the yield strength,tensile strength and elongation after breaking of the cooling specimen are reduced,which are reduced by 334 MPa,56 MPa and 0.9%,respectively.

关 键 词：22MnB5 加热速率 热成形 贝氏体 铁素体 抗拉强度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]