弹簧钢轧制过程方坯凝固组织及偏析的遗传性研究

来源期刊：钢铁2010年第9期

论文作者：杨武 陶红标 赵沛 颜慧成 仇圣桃

文章页码：32 - 35

关键词：弹簧钢； 遗传性； 偏析； 凝固组织

Key words：spring steel； heredity； segregation； solidification structure

摘    要：为了分析轧制过程方坯凝固组织及偏析的遗传性,以具有不同等轴晶率和偏析度的60Si2Mn方坯为试验对象,将断面为150 mm×150 mm的铸坯轧制成直径分别为75 mm和25 mm的2种棒材,检测了具有不同等轴晶率铸坯的偏析指数及钢材内部不同位置的力学性能。结果表明,在等轴晶率为42.7%~50.0%的范围内,铸坯距中心21.2 mm以外的偏心区域,碳的偏析指数并未随着等轴晶率的增加而提高;钢材的内部存在疏松和轻微偏析,且中心区域的力学性能相对更差,因此铸坯的中心偏析、疏松等缺陷会遗传至钢材;25 mm圆钢的力学性能及均匀性均优于75 mm圆钢,所以压下量的增加可减轻铸坯中心偏析的遗传性影响。

Abstract: In order to study heredity of solidification structure and segregation of spring steel billet rolled,the 60Si2Mn billets with different equiaxed grain rate and segregation degree were used as experiment objects.The billets with 150mm×150mm section were rolled into 2 round bars with 75mm and 25mm diameter separately.The mechanical properties at interior different position of rolled steel and segregation index of billets with different equiaxed grain rate were measured.The results show that the carbon segregation index in off center area where the distance to billet core exceed 21.2mm does not improved while equiaxed grain rate is increased.Porosity and light segregation existed within rolled steel and the inner mechanical property is poor relatively.Therefore central segregation and porosity of billet would inherit to rolled steel.The mechanical property and its uniformity of round bar whose diameter is 25mm is better than that of round bar whose diameter is 75mm.As a result,adding rolling reduction would lighten heredity effect of billet central segregation.