高强钢的热塑性流动规律  

Thermoplastic flow law of high-strength steel

作　　者：孙福臻 刘子知 张泉达 吉日格勒 Sun Fuzhen;Liu Zizhi;Zhang Quanda;Ji Rigele(State Key Laboratory of Advanced Forming Technology and Equipment,China Academy of Machinery Science and Technology Group,Beijing 100044,China;School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中国机械科学研究总院集团有限公司先进成形技术与装备国家重点实验室,北京100044 [2]北京科技大学机械工程学院,北京100083

出　　处：《锻压技术》2021年第12期216-223,共8页Forging & Stamping Technology

基　　金：国家科技重大专项(2019ZX04004001)。

摘　　要：针对两种应用在汽车的高强硼钢材料,通过力学试验和微观组织试验相结合的方法研究其热塑性流动规律,为高强钢热成形提供工艺参数依据。采用Gleeble-1500热模拟机进行高温热拉伸试验,研究在变形温度为600~800℃、应变速率为0.01~1 s^(-1)条件下两种材料热成形时的热塑性流动性;进行冷却速度试验,并对试验后的板材件进行单向拉伸试验和金相组织分析,进一步研究材料在热环境下的热塑性流动规律。结果表明,随着应变速率的增加,材料的塑性流动应力随之增加,加工硬化现象也越来越明显,变形温度的升高使材料的流动应力水平明显下降;对于Al-Si镀层钢板,提高变形温度,有助于马氏体的形成和材料冷却后强度及硬度的提升。For the two kinds of high-strength boron steel materials used in automobiles,the thermoplastic flow laws were studied by combining with mechanical test and microstructure test to provide a basis of process parameters for thermoforming of high-strength steel.Then,the high temperature thermal tensile tests were conducted by thermal simulator Gleeble-1500,and the plastic flow properties of the two kinds of materials during the thermoforming at deformation temperature of 600-800℃and strain rate of 0.01-1 s^(-1) were studied.Furthermore,the cooling rate test was carried out,and the uniaxial tensile test and the metallographic analysis of tested sheet parts were carried out to further study the thermo plastic flow laws of the material under the thermal environment.The results show that as the strain rate increases,the plastic flow stress of the material increases,the work hardening phenomenon becomes more and more obvious,and the increasing of the deformation temperature makes the flow stress level of the material drop significantly.For Al-Si coated steel sheet,increasing the deformation temperature helps the formation of martensite and the improvement of the strength and hardness after the material is cooled.

关 键 词：硼钢 拉伸试验 热成形 金相组织分析 热塑性流动规律 

分 类 号：TG142.1[一般工业技术—材料科学与工程]