近终形连铸镍铜铸铁空心型材及其在耐磨镶圈上的应用

Hollow Cu-Ni Cast Iron Profiles Produced by Near Net-shape Continuous Casting and Its Application in Wear Rings

用垂直连续铸造方法拉制的近终形镍铜铸铁空心型材,较之传统铸造的环坯,其共晶团体积缩小了8~10倍,故在随后与铝合金熔液的浸渗熔接时,作为原子扩散通道的晶界面积成倍增加,使得浸渗速度显著加快,获得了较厚的铝铁化合物层;连铸型材断面上的石墨裸露面积仅有6.5%,大大减少了无效熔接面积。这些因素都使铝铁界面上的熔接强度成倍提高。此外,将空心型材的外圆拉制成花键形,可以使材料利用率由传统的不足40%提高到70%以上。

The dimension of eutectic cell in the hollow near-net shape Cu-Ni cast ion produced by a vertical continuous casting is 8-10 times smaller than that in hollow Cu-Ni cast iron produced by a conventional casting, so their grain boundary area, which is channels for the atom to diffuse, will be multiplied and then the rate of A1 atom diffusing through these channels will be increased greatly, thus the layer of A1-Fe compounds will be thickened when they are welded with A1 alloy molten via infiltration. At the same time, the exposed area of the graphite in their section is only 6.5% of the whole section, which will decrease greatly invalid welding area. The thick layer of A1-Fe compounds and the low invalid-welding area will make the welding strength of A1-Fe interface grow exponentially. Besides these, when external circle of the hollow profiles were made into a spline, the material utilization of the hollow profiles can exceed 70%, while the material utilization is below 40% when the splines were made from the profiles produced by a conventional casting.