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（中南大學(xué)土木工程學(xué)院， 長沙 410075）
［摘要］通過對HRB500高強鋼筋及其閃光對焊焊接試件開展靜力、疲勞性能試驗，探索HRB500高強鋼筋閃光對焊的適用性，其中試件直徑包括16，20，25，32mm，采用現(xiàn)場常規(guī)焊接工藝，焊接接頭不進行后處理加工。試驗結(jié)果表明：焊接試件屈服強度隨直徑的增大而下降，但下降幅度不大，均能滿足其屈服強度標(biāo)準值要求；其塑性性能隨直徑的增大而有所下降，直徑25mm及以下的焊接鋼筋試件能滿足規(guī)范要求，但直徑32mm的焊接鋼筋試件易出現(xiàn)脆性斷裂現(xiàn)象。試件的疲勞強度尺寸效應(yīng)顯著，隨直徑的增大，疲勞強度明顯減小，直徑32mm的焊接鋼筋試件的1000萬次疲勞荷載對應(yīng)的應(yīng)力幅僅約為直徑16mm焊接鋼筋試件的55%。綜合考慮延性、疲勞性能等，建議常規(guī)工藝水平下，直徑32mm及以上的HRB500高強鋼筋焊接連接不宜采用閃光對焊連接方式。
［關(guān)鍵詞］HRB500高強鋼筋； 閃光對焊； 疲勞強度； 力學(xué)性能； 適用性
中圖分類號：TU511文獻標(biāo)識碼：A文章編號：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
*中國鐵路總公司科研試驗項目（z2014-038），中南大學(xué)中央高校基本科研業(yè)務(wù)費專項基金(2017zzts155)。
作者簡介：盛興旺，博士，教授，博士生導(dǎo)師，Email：shengxingwang@163.com。
