结晶器振动对2Cr13不锈钢铸坯及轧制质量的影响

Influence of crystallizer vibration on quality of casting billet and rolling for 2Cr13 stainless steel

针对某钢厂生产的规格为150 mm×150 mm的2Cr13不锈钢铸坯出现的凹陷状、钩状振痕及轧制线材结疤、裂纹等质量问题,分析了铸坯表面缺陷的产生机理,提出了铸坯连铸生产的结晶器振动优化方案,并进行了工业验证。结果表明:2Cr13不锈钢铸坯的表面缺陷是由结晶器负滑脱时间偏长造成的;在常规拉坯速度(1.2 m·min^(-1))下,相对于结晶器正弦振动,采用结晶器非正弦振动的优化方案,负滑脱时间和负滑脱率分别从0.18 s和38%降低至0.12 s和33%;通过适当降低负滑脱时间和负滑脱率,有效地改善了2Cr13不锈钢铸坯的表面质量,轧制线材的表面质量不良率也由4.5%降低至0.8%,表面裂纹的最大深度由327.89μm降低至94.34μm。

In response to the quality issues such as concave and hooked vibration marks,as well as rolling wire scars and cracks in the production of 150 mm×150 mm 2Cr13 stainless steel casting billets by a certain steel plant,the production mechanism of surface defects on the casting billets was analyzed,and an optimization scheme for crystallizer vibration in the continuous casting production of casting billet was proposed and verified in industry.The results indicate that the surface defects of 2Cr13 stainless steel casting billets are caused by the prolonged negative slip time of crystallizer.At a conventional casting speed of 1.2 m· min^(-1),compared to the sinusoidal vibration of crystallizer,a non-sinusoidal vibration optimization scheme is adopted for the crystallizer vibration.The negative slip time and negative slip rate are reduced from 0.18 s and 38% to 0.12 s and 33%,respectively.By appropriately reducing the negative slip time and negative slip rate,the surface quality of 2Cr13 stainless steel casting billets is effectively improved.The surface quality defect rate of rolled wire is reduced from 4.5% to 0.8%,and the maximum depth of surface cracks is decreased from 327.89 μm to 94.34 μm.