β相控制法改进黄铜合金的热加工性能  

Improving hot working properties of brass alloy byβphase control method

作　　者：杨春秀 娄花芬 陈忠平 向朝建 张曦 王苗苗 YANG Chun-xiu;LOU Hua-fen;CHEN Zhong-ping;XIANG Chao-jian;ZHANG Xi;WANG Miao-miao(Chinalco Research Institute of Science and Technology Co Ltd,Beijing 102209,China;Kunming Metallurgical Research Institute Co Ltd Beijing Branch,Beijing 102209,China)

机构地区：[1]中铝科学技术研究院有限公司,北京102209 [2]昆明冶金研究院有限公司北京分公司,北京102209

出　　处：《材料热处理学报》2023年第12期160-167,共8页Transactions of Materials and Heat Treatment

摘　　要：通过立式半连铸方法制备了Cu-40Zn-1Pb-0.15Fe-0.03Ni双相黄铜合金,针对热轧开裂问题,采用Gleeble-3500热模拟机对合金进行圆柱体压缩试验和扁平压缩试验,研究了双相黄铜合金在变形温度为600~780℃及应变速率为0.01~10 s^(-1)的条件下的热变形行为和热轧工艺性能。通过应力-应变曲线分析得到了合金的本构方程,计算绘制了热加工图,分析了热机械加工(TMP)诱导的α-β相变对α和β相的形成和铅颗粒分布的影响,利用热加工图结合显微组织确定了合金的热变形的流变失稳区和最佳变形参数。结果表明:双相黄铜合金加工过程主要存在两个失稳区:1)变形温度为670~710℃,应变速率为2.5~10 s^(-1)的区域;2)变形温度为750~780℃,应变速率为5~10 s^(-1)的区域。在较低温区(690℃以下),合金为α+β双相组织,且随着温度升高合金中β相占比逐渐增大、α相逐渐球化;在中温区(700~750℃),合金基本为β单相组织,利于热轧加工;在高温区(750℃以上),从β相组织的晶界处生长出针状α相,容易造成合金热轧开裂。Cu-40Zn-1Pb-0.15Fe-0.03Ni dual phase brass alloy was prepared by vertical semi continuous casting method.In response to the problem of hot rolling cracking,cylindrical compression tests and flat compression tests were conducted on the alloy using a Gleeble-3500 thermal simulator.The hot deformation behavior and hot rolling process performance of the dual phase brass alloy were studied under deformation temperature of 600-780℃and strain rate of 0.01-10 s^(-1).The constitutive equation of the alloy was obtained through stressstrain curve analysis,and the hot working diagram was calculated and drawn.The influences ofα-βphase transformation induced by thermomechanical processing(TMP)on the formation ofαandβphases and the distribution of Pb particles were analyzed,and the flow instability zone and optimal deformation parameters for thermal deformation of the alloy were determined using hot working diagram combined with microstructure.The results show that there are mainly two instability zones during the processing of the dual phase brass alloy:1)the deformation temperature is 670-710℃,and the strain rate is 2.5-10 s^(-1);2)the deformation temperature is 750-780℃,and the strain rate is 5-10 s^(-1).In the lower temperature range(below 690℃),the microstructure of the alloy is mainlyα+βdual phase,and as the temperature increases,the proportion ofβphase in the alloy gradually increases and theαphase gradually spheroidized.In the medium temperature range(700-750℃),the microstructure of the alloy is basicallyβsingle phase,which is conducive to hot rolling processing.In high temperature range(above 750℃),needle-likeαphase grows from the grain boundaries of theβphase structure,resulting in an increase in the tendency of hot rolling cracking of the alloy.

关 键 词：铅黄铜 热加工 Α相 Β相 组织演变 力学性能 

分 类 号：TG146.1[一般工业技术—材料科学与工程]