重型异形坯铸坯表面横裂纹的成因分析与控制  

Cause Analysis and Control of Transverse Cracks on the Surface of Beam Blank

作　　者：胡林梅 沈昶[1] 王猛 HU Linmei;SHEN Chang;WANG Meng(Maanshan Iron and Steel Co.,Ltd.,Maanshan,Anhui 243000,China)

机构地区：[1]马鞍山钢铁股份有限公司,安徽马鞍山243000

出　　处：《冶金动力》2024年第1期86-89,共4页Metallurgical Power

摘　　要：针对国内某钢厂生产Q355级和Q420级异形坯低合金钢时产生铸坯表面横裂纹的现状,解析了连铸坯翼缘顶端横裂纹产生的机理和主要影响因素之间的对应关系,以降低重型异形坯铸坯横裂纹的发生率。研究结果表明铸坯表面横裂纹沿粗大的奥氏体晶粒开裂,Q355级钢低塑性区的温度范围为600~620℃和740~920℃,Q420级钢低塑性区的温度范围为600~950℃,通过提高铸机拉速、降低冷却水强度、降低钢种铝含量等工艺措施能有效控制重型异形坯铸坯翼缘表面横裂纹的产生。Aiming at the current situation of transverse cracks on the surface of billet casting produced by a domestic steel plant during the production of Q355 grade and Q420grade shaped billet low-alloy steel,the mechanism of transverse cracks at the flange tip of continuous casting billet and the corresponding relationship between the main influencing factors have been analyzed,so as to reduce the incidence of transverse cracks on the beam blank.The results show that the cast billet surface transverse cracks along the coarse austenite grain,the temperature range of Q355 grade steel low-plasticity zone is 600~620 ℃and 740~920 ℃,the temperature range of Q420 grade steel low-plasticity zone is 600~950 ℃.The process measures such as increasing the casting speed of the caster,reducing the intensity of cooling water,and reducing the aluminum content of the steel grade can effectively control the generation of transverse cracks on the surface of the flange tip of beam blanks.

关 键 词：重异连铸坯 翼缘顶端 横裂纹 

分 类 号：TG333[金属学及工艺—金属压力加工]