无铅易切削Bi白铜连铸工艺的研究

Continuous Casting Process of Free-cutting Bismuth-Bearing Zinc-Copper-Nickel With Pb-free

通过对Bi白铜代替Pb白铜的连铸研究发现,采用传统方式连铸的无Pb易切削Bi白铜芯部晶粒粗大,沿传热方向呈放射状长大,塑性较差。而在水平连铸炉出口处加装了强制加热和冷却装置后,促进了晶粒沿轴向生长,同时细化了晶粒。退火后的Bi白铜切削测试结果表明,无Pb易切削Bi白铜完全可以替代Pb白铜。

The continuous casting for bismuth-bearing zinc-copper-nickel alloy substituted for lead-bearing zinc-copper-nickel alloy was conducted because of the toxicity of the lead element.Experimental results reveal that in the tradintional way,the coarse grains can be observed with radiation growth along heattransferring direction,resulting in the the poor plasticity.After improvements,compulsive heating and cooling equipments were installed at the exit of horizontal continuous casting furnace,and the growth of grain crystal in axial direction was promoted and grain size was refined.The elongation rate of bismuthbearing zinc-copper-nickel alloy continuous casting rod is increased more than 20%,after annealing and cutting detection,it could completely replace lead-bearing zinc-copper-nickel alloy.