热处理工艺对CuZn_(39)Pb_(3)合金显微组织和应力腐蚀性能的影响  

Effects of Heat Treatment Process on Microstructure and Stress Corrosion Properties of CuZn_(39)Pb_(3)Alloys

作　　者：韦刚 朱志雄 童健 苟国庆[2] WEI Gang;ZHU Zhixiong;TONG Jian;GOU Guoqing(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 611700,China)

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009 [2]西南交通大学材料科学与工程学院,四川成都611700

出　　处：《热加工工艺》2024年第6期14-20,25,共8页Hot Working Technology

基　　金：国家自然科学基金项目(51905143);安徽省自然科学基金项目(1808085QE136);安徽省博士后项目(934269);2020年度材料先进技术教育部重点实验室(西南交通大学)开放基金项目(KLATM202008)。

摘　　要：采用光学显微镜(OM)、扫描电子显微镜(SEM)、应力腐蚀试验机和显微硬度计等研究了热处理工艺对CuZn_(39)Pb_(3)合金微观组织及合金在3.5wt%NaCl溶液中的应力腐蚀开裂敏感性和脱锌腐蚀敏感性的影响。结果表明:合金的应力腐蚀敏感性主要与α相的尺寸和所占比例、β相分布的连续性以及游离态的Pb分布相关。大尺寸的α相+连续分布的β相会导致局部腐蚀;游离态的Pb相倾向聚集在α相和β相界面处,粗大α相和连续分布的β相导致相界面面积减少会引起Pb相在相界面处聚集,降低界面结合力,降低材料的应力腐蚀性能。慢应变速率拉伸(SSRT)试验发现:退火态合金的应力腐蚀性能最差;经450℃时效后,合金中的细小α相对β相存在割裂作用,游离态Pb分布均匀,具有最佳的综合力学性能和应力腐蚀性能。浸没试验发现,退火态合金的脱锌腐蚀敏感性最高,450℃时效态合金脱锌腐蚀敏感性最低,与其应力腐蚀性能表现出一致性。The effects of heat treatment on the microstructure of CuZn_(39)Pb_(3)alloy and the susceptibility to stress corrosion cracking and dezincification corrosion in 3.5wt%NaCl solution were studied by means of optical microscope(OM),scanning electron microscope(SEM),stress corrosion tester and microhardness tester.The results show that the stress corrosion sensitivity of the alloy is mainly related to the size and proportion of theαphase,the continuity of theβphase distribution and the Pb distribution of the free state.Local corrosion is caused by largeαphases and theβphases of the continuous distribution.The Pb phase tends to gather at the interface between theαphase and theβphase.The reduction of phase interface area caused by coarseαphase and continuously distributedβphase will cause the Pb phase to gather at the phase interface,reduce the interfacial adhesion and reduce the stress corrosion performance of the material.A slow strain rate tensile(SSRT)test shows that the stress corrosion performance of the annealing alloy is the worst.The fineαrelativelyβphases in the alloy are separated after 450℃aging,and the free state Pb distributes evenly,which have the best comprehensive mechanical properties and stress corrosion properties.The immersion test shows that the dezincification corrosion sensitivity of the annealing alloy is the highest.The dezincification corrosion sensitivity at 450℃of the aging alloy is the lowest,which is consistent with its stress corrosion performance.

关 键 词：CuZn_(39)Pb_(3)合金 热处理 脱锌腐蚀 应力腐蚀 

分 类 号：TG161[金属学及工艺—热处理]