淬火介质对7050铝合金热锻件组织和性能的影响  

Effect of quenching medium on microstructure and properties of 7050 aluminum alloy hot forgings

作　　者：石佩斐 张辉 Shi Peifei;Zhang Hui(School of Mechanical Engineering,Zhengzhou University of Science and Technology,Zhengzhou Henan 450064,China;Hi-Tech Heavy Industry Co.,Ltd.,Zhengzhou Henan 450001,China)

机构地区：[1]郑州科技学院机械工程学院,河南郑州450064 [2]恒天重工股份有限公司,河南郑州450001

出　　处：《金属热处理》2024年第1期290-295,共6页Heat Treatment of Metals

基　　金：河南省科技重点科技攻关项目(212102210348)。

摘　　要：选用某汽车用7050铝合金热锻件,以20 K/min的速率将试样快速加热至746 K并保温1 h,然后将试样快速转移到浓度分别为0%(水)、5%、10%、20%、30%的PAG聚合物溶液和空气中淬火,再采用T74工艺(393 K保温6 h, 436 K保温12 h)进行时效处理,分析不同PAG淬火剂浓度对7050铝合金试样残余应力、第二相粒子、抗拉强度和屈服强度的影响规律。结果表明,随着PAG淬火剂浓度的增加,该铝合金试样的残余应力逐渐减弱,第二相体积分数逐渐上升,抗拉强度和屈服强度逐渐下降。综合考虑,PAG淬火剂浓度设为10%~20%时,7050铝合金淬火试样具有相对较低的残余应力,其抗拉强度为512~519 MPa,屈服强度为472~478 MPa,能够满足抗拉强度大于510 MPa、屈服强度大于455 MPa的力学性能要求。A 7050 aluminum alloy hot forging for automobile was selected,and the specimens were rapidly heated to 746 K with a rate of 20 K/min and held for 1 h.Then the specimens were rapidly transferred to the PAG polymer solution with concentrations of 0%(water),5%,10%,20%,30%and air to quench respectively,and finally the aging treatment was carried out using the T74 process(393 K for 6 h and 436 K for 12 h).The effects of different PAG quenchant concentrations on the residual stress,second⁃phase particles,tensile strength and yield strength of the 7050 aluminum alloy specimens were analyzed.The results show that with the increase of PAG quenchant concentration,the residual stress of the aluminum alloy specimens gradually weakens,the volume fraction of the second phase gradually increases,and the tensile strength and yield strength gradually decrease.Considering comprehensively,the PAG quenchant concentration of 10%⁃20%can meet the technical requirements,with which the quenched specimens of the 7050 aluminum alloy have relatively low residual stress,the tensile strength is 512⁃519 MPa and the yield strength is 472⁃478 MPa,and meeting the mechanical properties requirements of tensile strength greater than 510 MPa and yield strength greater than 455 MPa.

关 键 词：PAG淬火介质 7050铝合金 微观组织 力学性能 

分 类 号：TG166.3[金属学及工艺—热处理]