（中南大学土木工程学院， 长沙 410075）

［摘要］通过对HRB500高强钢筋及其闪光对焊焊接试件开展静力、疲劳性能试验，探索HRB500高强钢筋闪光对焊的适用性，其中试件直径包括16，20，25，32mm，采用现场常规焊接工艺，焊接接头不进行后处理加工。试验结果表明：焊接试件屈服强度随直径的增大而下降，但下降幅度不大，均能满足其屈服强度标准值要求；其塑性性能随直径的增大而有所下降，直径25mm及以下的焊接钢筋试件能满足规范要求，但直径32mm的焊接钢筋试件易出现脆性断裂现象。试件的疲劳强度尺寸效应显著，随直径的增大，疲劳强度明显减小，直径32mm的焊接钢筋试件的1000万次疲劳荷载对应的应力幅仅约为直径16mm焊接钢筋试件的55%。综合考虑延性、疲劳性能等，建议常规工艺水平下，直径32mm及以上的HRB500高强钢筋焊接连接不宜采用闪光对焊连接方式。

［关键词］HRB500高强钢筋； 闪光对焊； 疲劳强度； 力学性能； 适用性

中图分类号：TU511文献标识码：A文章编号：1002-848X(2018)02-0023-04

Study on applicability of flash butt welding of HRB500 high strength steel bars

Sheng Xingwang, Zheng Weiqi, Lei Jizhou, Sheng Sheng

(School of Civil Engineering， Central South University， Changsha 410075， China)

Abstract:The applicability of flash butt welding for HRB500 high strength steel bars was studied by testing the mechanical properties and fatigue performance of the base metal specimens and the flash butt welding specimens. The specimens included four different diameters of 16, 20, 25， 32mm, and the conventional welding procedure was adopted, and the welding joint was not processed. The experimental results show that the welding yield strength of the specimen  decreases with the increase of the diameter, but the decline is not large, and it can meet the requirements of the standard value of yield strength; plastic properties decrease with the increase of the  diameter, and welded steel bar specimens with the diameter of 25mm and below can meet the specification requirements, but the welded steel bar specimens with the diameter of 32mm are prone to brittle fracture phenomenon. The size effect of fatigue strength of the specimen is remarkable, and the fatigue strength decreases with the increase of the diameter. The stress amplitude corresponding to the 10 million fatigue load of the welded specimen with diameter of 32mm is only about 55% of that of the welded steel bar specimen with diameter of the 16mm. Considering the ductility and fatigue properties, it is suggested that the flash butt welding should not be used in HRB500 high strength steel bars of diameter 32mm and above in conventional welding process.

Keywords:HRB500 high strength steel bar; flash butt welding; fatigue strength; mechanical property; applicability

 *中国铁路总公司科研试验项目（z2014-038），中南大学中央高校基本科研业务费专项基金(2017zzts155)。

作者简介：盛兴旺，博士，教授，博士生导师，Email：shengxingwang@163.com。