30CrMnMo钢管热处理裂纹原因分析  

Analysis of Causes for Heat Treatment-related Cracking of 30CrMnMo Steel Tube

作　　者：余世杰[1,2] 陈猛[1] 袁鹏斌[1] 

机构地区：[1]上海海隆石油管材研究所,上海200949 [2]西南石油大学,四川成都610500

出　　处：《钢管》2017年第3期40-44,共5页Steel Pipe

摘　　要：某公司一批30CrMnMo原料钢管在调质热处理后的超声波检验中,发现大部分管体存在热处理裂纹缺陷。对带有缺陷的管体和入厂原料管体分批取样,采用直读光谱仪、金相显微镜、扫描电镜等设备分析缺陷样品的化学成分、金相组织、宏观和微观形貌。分析结果表明:该批原料钢管存在轧管折叠、内壁凹凸不平和P元素偏析缺陷;在热处理淬火时,上述缺陷引起应力集中,产生大量淬火裂纹,导致管体开裂。建议钢管原料厂改善轧制工艺,减少轧制折叠、凹坑缺陷;并且提高钢材冶炼质量,严格控制P等有害元素的含量。In a certain domestic company, a batch of 30CrMnMo steel pipes as outside-supplied blanks and having undergone quenching ＆ tempering treatment are tested with the ultrasonic detection process, As a result most of the pipes tested are bearing heat treatment-related defects. Test samples are taken from some defective pipe bodies, and from bodies of some blank pipes as raw materials. The defective samples are analyzed for their chemical composition, metallographic structure, and macro and micro morphologies by means of direct-reading spectrometer, metalloscope, and scanning electron microscope, etc. The results reveal that original defects like folding, uneven inner surface, and P segregation stay with the batch of outside-supplied blank pipes. And when the pipes are quenched, it is these original defects that cause stress concentration which leads to development of lots of quenching cracks, and in turn cracking of the pipe body. Accordingly, it is suggested for the pipe-supplying manufacturer to take such corrective actions as improving the rolling process for eliminating defects like rolled-folding and pit, etc., and further improving the metallurgical quality of the steel, and strictly controlling the contents of hazardous chemical elements like P, and so on.

关 键 词：钢管原料 热处理 淬火裂纹 轧管折叠 元素偏析 

分 类 号：TG161[金属学及工艺—热处理]