Ce-Mg合金加入对GCr15轴承钢夹杂物和凝固组织的影响

研究了加Ce(0～0.32%)-Mg(0～0.04%)合金对GCr15轴承钢的铸态夹杂物和凝固组织的影响。结果表明：添加Ce-Mg合金，能够促使夹杂物改性，生成大量的形状较规则，尺寸细小，分布弥散的Ce、Mg夹杂物；并且当0.016%Ce]、0.002%Mg]时，夹杂物更为细小弥散。在凝固组织方面，随着Ce-Mg合金的增加，钢的铸态组织碳化物分布更为均匀，网状碳化物的网状结构变得更加纤薄，当0.016%Ce]、0.002%Mg]时，珠光体片层更为纤薄，片层间距更小。Ce-Mg合金的添加能够显著减弱钢中C和Cr在枝晶间与枝晶干的合金元素偏析，减少枝晶间距，阻碍枝晶的粗化。

Effect of Adding Ce-Mg Alloy on Inclusion and Solidification Microstructure of GCr15 Bearing Steel

The effects of adding Ce(0-0. 32% ) -Mg(0-0. 04% ) alloy on the as-cast inclusions and solidification organization of GCr15 bearing steel are investigated. The results show that the addition of Ce-Mg alloy can lead to the modification of inclusions and the generation of a large number of Ce-and Mg inclusions with regular shape, fine size and disperssed distribution ；and the inclusions are more fine and diffuse as 0.016% Ce] and 0.002% Mg]. With the increase of the mass fraction of Ce-Mg alloy, the distribution of carbides in the as-cast structure of steel becomes more uniform and the reticular carbide network structure becomes thinner, and as 0.016% Ce] and 0. 002% Mg], the pearlite lamellae is the thinner and the lamellae spacing is the minimized. The addition of Ce-Mg alloy can significantly reduce the segregation of C and Cr elements between dendrites and dendrite stem, and reduce the dendrite spacing to hinder the coarsening of dendrites.