破碎锤钎杆锥头劈裂原因分析  

Analysis of the cause of splitting of rod cone

作　　者：王小忠 WANG Xiaozhong(Zenith Steel Group Company Limited,Changzhou 213011,Jiangsu,China)

机构地区：[1]中天钢铁集团有限公司,江苏常州213011

出　　处：《四川冶金》2023年第4期61-65,共5页Sichuan Metallurgy

摘　　要：42CrMo钢Φ180 mm热轧圆钢制造的破碎锤钎杆,某客户在使用不久便产生钎杆锥头纵向劈裂现象。经对劈裂钎杆进行断口形貌、金相组织等理化分析。结果表明:钎杆锥头纵向劈裂属于疲劳断裂,引起疲劳断裂的主要因素是钎杆心部存在沿纵向贯通性裂纹,而贯通性裂纹则来源于原材料圆钢,其原因是连铸坯中心缩孔在轧制时未能完全轧合有关。通过试验方案改善连铸坯内部质量,优化轧制工艺,完善入坑缓冷制度,最终解决大规格圆钢心部裂纹的质量问题。The phenomenon of longitudinal splitting of drill rod cone head was found not long after the use of the drill rod made of Q180mm hot rolled round steel of 42CrMo steel.The fracture morphology,metallographic structure and scanning electron microscope were examined and analyzed.The results show that the longitudinal splitting of drill rod cone head belongs to fatigue fracture.The main factor causing fatigue fracture is that there is a longitudinal through crack in the core of drill rod,and the through crack comes from the raw material round steel,the reason is that the central shrinkage cavity of continuous casting billet is not completely rolled.Through improving the internal quality of continuous casting billet,improving the rolling process,improving the slow cooling into the pit and other measures to avoid similar quality problems again.

关 键 词：破碎锤钎杆 42CRMO钢 疲劳断裂 劈裂 

分 类 号：TG142.1[一般工业技术—材料科学与工程]