轴承钢不同连铸工艺偏析程度对比研究

Comparative Study on Segregation Degree of Bearing Steel Under Different Continuous Casting Processes

采用淬火+回火方法,研究了不同连铸工艺下轴承钢钢坯的偏析情况。结果表明,不同工艺下连铸坯边部偏析均较轻,混晶区和中心区域差别较大。低拉速和轻压下的采用对轴承钢连铸坯偏析影响大,低过热度相对没有表现出明显的影响。从混晶区到铸坯中心,偏析严重区域出现了一次共晶碳化物,并伴随着Ti N、Mn S等夹杂物,对产品疲劳寿命造成了影响。

By using the method of quenching and tempering, the segregation of bearing steel blank under different continuous casting technologies was investigated. The results show that, slight segregation appears on the edges of continuous casting blank under different technologies, but there is great difference in mixed zone and center zone. The low drawing speed and soft-reduction technology has more effect on segregation of continuous casting bearing steel blank, while the low superheat degree has no obvious effect. From mixed zone to center zone of blank, primary eutectic carbide with some impurities like TiN, MnS appears in the zone of serious segregation, which has bad influence to fatigue life of products.