含Nb不锈钢中厚板中间裂纹分层原因分析及控制  

Cracking analysis and improved measures of intermediate crack in hot rolled medium plate of niobium-bearing stainless steel

作　　者：冯翰秋 郎宇平[1] 屈华鹏[1] 陈海涛[1] FENG Han-qiu;LANG Yu-ping;QU Hua-peng;CHEN Hai-tao(Research Institute of Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《中国冶金》2022年第6期147-154,共8页China Metallurgy

摘　　要：针对含Nb不锈钢热轧中厚板出现的中间裂纹分层以及力学性能不合问题,通过金相观察、扫描电镜、相分析和力学性能检测等手段对中间裂纹分层以及力学性能不合原因进行研究。结果表明,Mo、Nb在凝固过程中偏析严重、形成σ相和Z相(CrNbN)是产生热轧中厚板中间裂纹分层以及力学性能不合的主要原因。通过降低Nb含量,优化热处理制度,降低钢液过热度,确定合理冷却制度,添加电磁搅拌工艺,可以有效地减小中间裂纹分层的发生并提高低温冲击韧性。Aiming at the problems of intermediate crack delamination and unqualified mechanical properties in hot rolled medium plate of niobium-bearing stainless steel,the causes of intermediate crack delamination and unqualified mechanical properties were studied by means of metallographic observation,scanning electron microscope,phase analysis and mechanical property detection.The results show thatσphase and Z phase(CrNbN)which formed by the serious segregation of Mo and Nb are the main causes of the intermediate crack delamination and unqualified mechanical properties in hot rolled medium plate.By reducing Nb content,optimizing heat treatment system,reducing liquid steel superheat,determining reasonable cooling system and adding electromagnetic stirring process,the occurrence of intermediate crack can be effectively reduced and low temperature impact toughness can be improved.

关 键 词：铌 中厚板 中间裂纹 偏析 成分控制 不锈钢 

分 类 号：TG142.71[一般工业技术—材料科学与工程]