中厚板表面爪型裂纹成因分析  

Analysis on Cause of Claw Type Surface Crack of Heavy and Medium Plate

作　　者：郭永民[1] 李龙[1] 

机构地区：[1]天津钢铁集团有限公司炼钢厂,天津300301

出　　处：《天津冶金》2013年第A01期47-50,共4页Tianjin Metallurgy

摘　　要：采用扫描电镜及高倍金相分析了具有爪型裂纹板材的成分及金相组织。结合定性分析及对照实验的方法,确定了查找问题原因的方向。通过分析铸坯热送时间与板材爪裂的对应关系,发现了板材爪裂的形成规律。指出在铸坯热送过程中,过饱和碳化物或氮化物的析出,恶化了铸坯的热塑性,最终导致钢板表面形成爪型裂纹缺陷。提出了通过铸坯下线堆冷或适当延长铸坯热送时间来消除此类缺陷的方法。The study direction for claw type surface crack is defined by analyzing the component and metallographic structure of the above defect with scanning electron microscope and metallographic microscope via qualitative analysis and comparison experiment method. Analysis and statistics of the corresponding relationship of hot charging time and claw crack find the regularity of crack formation. It is further analyzed that the precipitation of carbide and nitride in oversaturated state in hot charging degrades the hot plasticity of the slab, which eventually causes claw crack on plate surface. This defect is eliminated by adopting offline stack cooling and prolonging hot charging time.

关 键 词：爪型裂纹 氩气泡 铸坯 热送时间 

分 类 号：TG245[金属学及工艺—铸造]