510L汽车大梁钢表面横裂纹发生机理及控制措施  

Formation Mechanism and Control Measures of Transverse Crack on the Surface of 510L Automobile Beam Steel

作　　者：李峰[1] 黄财徳 李滨 胡文才 岳尔斌 Li Feng;Hunag Caide;Li Bin;Hu Wencai;Yue Erbin(Shougang Jingtang Iron and Steel United Co.,Ltd.;Jiangsu Metallurgical Technology Research Institute)

机构地区：[1]首钢京唐钢铁联合有限责任公司 [2]江苏冶金技术研究院

出　　处：《宽厚板》2021年第4期23-26,共4页Wide and Heavy Plate

摘　　要：含Nb类510L汽车大梁钢板坯横裂纹发生率较高,无法实现热装热送。针对京唐公司连铸机设备工艺条件,控制钢水N含量至40×10^(-6)以下,减少板坯中AlN、NbN的析出;优化二冷水,将4#~8#扇形段的二冷水流量下调20%,矫直时板坯表面温度避开第Ⅲ脆性区;控制扇形段辊缝精度在±0.5 mm范围内,降低铸坯机械应力。采取以上措施后,板坯横裂纹的发生率由25%下降至0.8%。The Nb-bearing automobile beam steel plate 510L has higher transverse cracking ratio,which is impossible for hot charging and hot delivering.On the basis of the technological conditions of continuous caster of Jingtang Iron and Steel,the segregation of AlN and NbN in slab is reduced by controlling the nitrogen content in molten steel to values below 40×10^(-6),the flowrate of secondary cooling water for segments from No.4 to No.8 is regulated 20%down by optimizing secondary cooling water,the surface temperature of strand being straightened is avoided from the third brittle zone,the mechanical stress of strand is reduced by controlling the roll gap accuracy of segments to the tolerance of±0.5 mm.After the implementation of the above measures,the transverse cracking ratio of slab is decreased from 25%to 0.8%.

关 键 词：横裂纹 510L 二冷水 热装热送 

分 类 号：TF777[冶金工程—钢铁冶金]