摘要
介绍了UNS N08810管冷扩外径的工艺路线及主要工艺参数,通过光学显微镜、扫描电子显微镜、能谱分析仪并结合热力学曲线分析冷扩裂纹产生的原因.分析认为:管坯固溶温度较高,晶粒度级差大,非正常混晶,降低了钢的机械性能;脆性TiC在晶界形成大尺寸的TiC薄膜,给裂纹提供了一个低能扩展的通道,增加了裂纹产生的倾向.采用多道次大变形量冷轧,以及控制热处理工艺和冷却方式,可以有效地细化组织晶粒,减少扩拔裂纹的产生.
Described in the paper are the process path and major technological parameters of the cold-(OD) expansion process for the UNS N08810 seamless steel tube. Analyzed are the causes for cracks of the said tube as occurring during the cold-expansion process by means of optical metallographic microscopy, SEM , EDS and the thermodynamic curve. The analysis result reveals the facts as follows. The mechanical properties of the tube are weakened due to such factors as rather high solid solution temperature of the mother tube, big grain size differential, and abnormal mixed grain, etc. Large-sized TiC films are formed by brittle TiC particles in the grain boundary, which provides a channel for low-energy expansion, and thus increases the tendency of the cracking Accordingly taking such measures as multi-pass/large deformation cold-rolling, and well-controlled heat treatment process, and proper cooling method will get the microstructure grains refined so as to reduce the occurrence of the crack during the cold-expansion (drawing) process.
作者
郭玲
赵明
庞于思
刘富强
王连华
刘静
GUO Ling;ZHAO Ming;PANG Yusi;LIU Fuqiang;WANG Uanhua;LIU Jing(Xinxing Ductile Iron Pipes Co., Ltd., Handan 560460, China)
出处
《钢管》
CAS
2019年第5期52-55,共4页
Steel Pipe
关键词
无缝钢管
N08810
冷轧
扩拔
裂纹
热处理
晶粒度
seamless steel tube
N08810
cold-rolling
expansion ( drawing)
crack
heat treatment
grain size
