废杂铜再生铅黄铜水平连铸异型管材及其显微组织分析  

Production of Abnormal-shape Profile with Pb Brass from Scrap Copper and its Microstructure

作　　者：戴浩[1] 马永存[1] 刘新才[1] 潘晶[1] 王永如 洪燮平 李红卫 张学士 楼春章 黄飞隆[1] 

机构地区：[1]宁波大学材料科学与化学工程学院,宁波市新型功能材料及其制备科学实验室-省部共建国家重点实验室培育基地 [2]宁波金田铜业(集团)股份有限公司

出　　处：《特种铸造及有色合金》2010年第4期382-385,共4页Special Casting & Nonferrous Alloys

基　　金：宁波市重大科技攻关项目(2007B10029);宁波大学王宽诚幸福基金资助项目

摘　　要：再生废杂铜在结晶器冷却水为40℃左右、950℃保温、以180～350mm/min连铸得到无裂纹的十二边形、最小壁厚为5mm的HPb58-2A异型管材;经金相、扫描电镜观察和能谱成分分析,结果表明,当相成分中w(Si)/w(Fe)为0.100以下时,初生相Fe基固溶体具有择优生长方向,形成树枝晶;当w(Si)/w(Fe)为0.178时,Fe-Si相形貌为多边形;α和β相先后凝固析出,两者同时向熔液中析出Pb,因此在后凝固的β相中Pb浓度较大,在α和β相交界处Pb浓度最大。在冷却过程中,Pb在α和β相中弥散长大,且在α和β相中Pb粒尺寸分别小于0.5μm和0.75μm,在两相交界处的β相中,Pb呈花瓣状,尺寸最大为2.5μm;细小的Pb粒使连铸异型管材在具有高的切削性能的同时还具有更高的力学性能。HPb58-2A dodecagon abnormal-shape tubes with 5 mm in the smallest thickness and crack free was produced with recycled scrap cooper by continuous casting at 950℃ and 180~350 mm/min in condition of cooling at 40℃. Microstructure of the tubes was analyzed by optical microscope (OM), SEM (scanning electron microscope) and EDS (energy dispersive spectrum). The results reveal that Fe based solid solution is formed into dendrite due to exhibiting preferred growth with mass ratio of Si via Fe increasing to 0.078, while with mass ratio of Si via Fe of 0.178, Fe-Si phase shows polygonal structure. α phase is solidified ahead to β phase , which results in the higher Pb concentration in latter solidified β phase and the highest ones in interface of α phase and β phase. During cooling process, Pb particles is dispersedly grown in α phase and β phase, and size of Pb particles in both α phase and in β phase are less than 0.5μm and 0.75μm, respectively. In addition, size of Pb particles exhibiting rosette structure in the β phase in interface reaches up to 2.5 μm. Fine Pb particle can not only ensure excellent cutting performance but also increase mechanical properties of continuous casting abnormal-shape tubes.

关 键 词：废杂铜再生 铅黄铜 Fe基固溶体 Pb基固溶体 水平连铸 

分 类 号：TG249.7[金属学及工艺—铸造] TG146.11[一般工业技术—材料科学与工程]