SCM440钢表面脱碳与开裂  

Surface decarburization and cracking behavior of SCM440 steel

作　　者：孔祥华[1] 唐晋[1] 孙瑞虹[1] 赵广宏[1] 孙彦辉[2] 袁国华 孙华 李翔 

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]北京科技大学冶金与生态工程学院,北京100083 [3]南京钢铁公司,江苏南京210035

出　　处：《材料热处理学报》2012年第3期142-145,共4页Transactions of Materials and Heat Treatment

基　　金：南京钢铁公司资助

摘　　要：研究了SCM440钢的开裂敏感性与轧后冷却过程中的温度、脱碳程度的关系。结果表明,轧后冷却过程中SCM440大盘条在表层以下30μm以内的区域产生的微裂纹引起了冷镦开裂。在轧后冷却过程SCM440盘卷表面发生脱碳。微裂纹主要在750～800℃范围内产生,由于在这个温度范围内SCM440钢处于两相区,发生了铁素体相变,在表层形成铁素体全脱碳层,最后由于组织应力形成了沿铁素体晶界扩展的微裂纹。Effects of decarburization and temperature in the cooling process after rolling on cracking sensitivity of SCM440 steel were studied.The results show that the micro-cracks occurred in surface layer less than 30 μm of the SCM440 steel coil caused the cold heading cracking.Surface decarburization of SCM440 steel coils occurs in the cooling process after rolling,and micro-cracks were formed mainly at 750-800℃.In this temperature range,ferrite forms in the fully decarburized layer on surface of SCM440 steel.As a result of microstructure stress,the micro-cracks are generated along ferrite grain boundaries finally.

关 键 词：开裂敏感性 脱碳 组织应力 

分 类 号：TG142.33[一般工业技术—材料科学与工程]