PMO作用对连铸轴承钢凝固组织及碳化物的影响

Influence of pulse magneto-oscillation on solidification structure and carbides in bearing steel billet

将脉冲磁致振荡(Pulse Magneto—Oscillation,简称PMO)凝固细晶技术应用于中天钢铁集团有限公司钢铁企业轴承钢的连铸生产中,对其铸坯及轧材进行连续取样,并对低倍组织及碳化物进行了检测。实验结果表明,经PMO处理后,铸坯中等轴晶占比明显增加,最高增加率达28.8%,且中心缩孔和缩松有明显改善。带状碳化物和液析碳化物的尺寸和分布也得到了明显改善,尺寸减小率最高分别达到81.9%和86.3%,这将对轴承钢的疲劳寿命起到积极的作用。

Pulse magneto oscillation (PMO)homogenization technique has been applied to improve the quality of bearing steel billet in Zenith Steel Group Company Limited.The solidified structure and carbides of produced bearing steel billet treated by PMO were investigated.The measured results showed that the area rate of equiaxed grain was significantly increased by a rate of 28.8%.In addition,the central shrinkage cavity and porosity were remarkably eliminated.It was found that the size and distribution of banded carbides and hydro carbides were obviously relieved.The size of carbides was reduced by a rate of 81.9% and 86.3%,respectively.The results suggested that the fatigue life of bearing steel treated by PMO could be extended.