气弹簧活塞杆表面裂纹形成原因及改进措施  

Causes and improvement measures of surface crack of gas spring piston rod

作　　者：刘金庆 朱帅 代芳音 曹长法 马春雨 Liu Jinqing;Zhu Shuai;Dai Fangyin;Cao Changfa;Ma Chunyu(Research Institute of Wire Materials,Qingdao Special Iron&Steel Co.,Ltd.,Qingdao 266043,China)

机构地区：[1]青岛特殊钢铁有限公司线材研究所,山东青岛266043

出　　处：《金属制品》2025年第1期36-39,45,共5页Metal Products

摘　　要：气弹簧活塞杆在制造过程中出现表面横向裂纹,对横向裂纹处的组织区域特征相进行了分析。结果表明:气弹簧活塞杆表面裂纹位置存在增碳和网状渗碳体,降低塑性,造成S45C盘条拉拔过程产生裂纹。分析认为,连铸坯局部增碳,轧制后控冷过程在该位置形成网状渗碳体。将拉速降低至1.03 m/min,浸入式水口插入深度提高到130~150 mm,结晶器电磁搅拌参数降低至220 A,3.5 Hz,消除了结晶器液面异常波动引起的铸坯局部增碳,避免了盘条出现网状渗碳体而导致的气弹簧活塞杆表面裂纹现象。Surface transverse crack of gas spring piston rod appeared in manufacturing process.The characteristic phases of microstructure region at transverse crack were analyzed.Results show that there are carburization and network cementite on surface crack of gas spring piston rod,which reduces plasticity and causes cracks in drawing process of S45C wire rod.Analysis shows that continuous casting billet is locally carburized,and network cementite is formed at this position during controlled cooling process after rolling.Casting speed was reduced to 1.03 m/min,immersion nozzle insertion depth was increased to 130~150 mm,and mold electromagnetic stirring parameter was reduced to 220 A,3.5 Hz,which eliminated local carburization of billet caused by abnormal fluctuation of mold liquid level,and avoided surface crack of gas spring piston rod caused by network cementite in wire rod.

关 键 词：气弹簧 活塞杆 增碳 网状渗碳体 横向裂纹 

分 类 号：TG156[金属学及工艺—热处理]