汽车用QP980钢模拟火灾后的组织与力学性能变化  

Evolution of microstructure and mechanical properties of QP980 steel for automobiles after simulated fire

作　　者：李文通 亓海全 笪仲钟[1,2,3] 万宇 王为民 姚小凤 李欣欣 谢盈盈 LI Wen-tong;QI Hai-quan;DA Zhong-zhong;WAN Yu;WANG Wei-min;YAO Xiao-feng;LI Xin-xin;XIE Ying-ying(School of Materials Science and Engineering,Guilin University of Technology,Guilin 541004,China;Key Laboratory of Nonferrous Metals and Materials Processing New Technology,Ministry of Education,Guilin University of Technology,Guilin 541004,China;Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of Resources,Guilin 541004,China;Sichuan Aviation Industry Chuanxi Machinery Co Ltd,Ya’an 625000,China)

机构地区：[1]桂林理工大学材料科学与工程学院,广西桂林541004 [2]桂林理工大学有色金属及材料加工新技术教育部重点试验室,广西桂林541004 [3]有色金属矿产勘查与资源高效利用省部共建协同创新中心,广西桂林541004 [4]四川航空工业川西机器有限责任公司,四川雅安625000

出　　处：《材料热处理学报》2025年第3期160-170,共11页Transactions of Materials and Heat Treatment

基　　金：广西科技重大专项(桂科AA22067079)。

摘　　要：采用热处理模拟车辆受火的方法,设定不同的受热温度和保温时间及冷却方式,研究了车身结构钢QP980受热后组织及力学性能的变化。结果表明:在100~700℃受热冷却后,QP980钢的组织主要为铁素体和马氏体,铁素体略有长大。高于500℃后,其强度显著下降,伸长率略有提高;800℃加热空冷时,QP980钢的组织由铁素体及马氏体和少量贝氏体组成,马氏体含量略有增加,强度升高,但伸长率下降;水冷时,组织转变为马氏体和铁素体,马氏体体积分数显著升高,故而强度增加,伸长率急剧下降。900~1000℃奥氏体相区加热空冷时,QP980钢的组织主要为铁素体、马氏体以及贝氏体,受晶粒长大的影响,综合力学性能均发生不同程度的下降;水冷后则由马氏体与贝氏体构成,强度较高,伸长率极低。QP980车辆结构件在100~1000℃受火后,性能均将出现不同程度的劣化,无法继续满足车辆服役条件。The method of simulating vehicle fire through heat treatment was adopted,and different heating temperatures,holding time and cooling methods were set to study the evolution of microstructure and mechanical properties of QP980 body structural steel after heating.The results show that after being heated at 100-700℃and cooled,the microstructure of the QP980 steel is mainly composed of ferrite and martensite,with slight growth of ferrite.Above 500℃,its strength significantly decreases and its elongation slightly increases.When heated at 800℃and air-cooled,the microstructure of the QP980 steel is composed of ferrite,martensite and a small amount of bainite,the martensite content slightly increases,and the strength increases,but the elongation decreases.When water-cooled,the microstructure transforms into martensite and ferrite,and the volume fraction of martensite significantly increases,resulting in an increase in strength and a sharp decrease in elongation.When heated at 900-1000℃which is the austenite phase zone and air-cooled,the microstructure of the QP980 steel is mainly composed of ferrite,martensite and bainite.Due to the influence of grain growth,the comprehensive mechanical properties all undergo varying degrees of decline.After water cooling,the microstructure is composed of martensite and bainite,with high strength and extremely low elongation.After being exposed to fire at 100-1000℃,the performance of the QP980 vehicle structural components will deteriorate to varying degrees and cannot continue to meet the service conditions of the vehicle.

关 键 词：QP980钢 先进高强钢 力学性能 显微组织 模拟火灾 

分 类 号：TG142.4[一般工业技术—材料科学与工程]