滚轧直螺纹钢筋接头疲劳试验断裂分析  

Fracture analysis of rolled straight thread reinforced bar joint fatigue test

作　　者：王军[1] 尹亚豪 苏建锋[1] 张龙龙 徐林 Wang Jun;Yin Yahao;Su Jianfeng;Zhang Longlong;Xu Lin(National Quality Supervision and Inspeetion Center for Metal Products,Zhengzhou 450001,China)

机构地区：[1]国家金属制品质量监督检验中心,河南郑州450001

出　　处：《金属制品》2018年第4期58-62,共5页Metal Products

摘　　要：对铁路工程用直螺纹钢筋接头进行质量检测,在疲劳试验过程中发生过早的断裂现象,采用外观缺陷分析、化学成分分析、金相分析及电镜微观分析等方法对断裂原因进行探究。结果表明:A型断口是由于钢筋端头未进行打磨、钢筋丝头无有效螺纹外露及套筒自身缺陷共同作用的结果;B型断口是由于钢筋丝头自身缺陷、套筒与钢筋丝头配合不良以及丝头螺纹加工缺陷共同作用的结果;C型断口是由于钢筋表面有挤压损伤缺陷产生应力集中引起。通过控制钢筋端头质量、控制丝头螺纹长度及加强套筒、钢筋质量检查可有效提高接头的疲劳寿命。The quality inspection of the joint of straight thread reinforced bar for railway engineering is carried out. The early rupture occurs during the fatigue test,and the reasons of the fracture are explored by means of appearance defect analysis,chemical composition analysis,microstructure analysis and microscopic analysis of electron microscope. The results show that the A type fracture is the result of the failure of the end of steel bar,the lack of effective thread and the self defects of the sleeve. The B type fracture is the result of the self defects of the steel wire head,the poor matching of the sleeve and the wire head and the machining defects of the thread head,and the C type fracture is caused by stress concentration on the surface of steel bar due to extrusion damage. The fatigue life of the joints can be effectively improved by controlling the quality of the steel ends,controlling the thread length of the threaded heads and strengthening the inspection of the quality of the sleeves and reinforcing bars.

关 键 词：螺纹钢筋 疲劳断裂 金相组织 表面损伤 非金属夹杂物 

分 类 号：TD532[矿业工程—矿山机电]