利用低相变点焊条熔修方法改善焊接接头疲劳强度的试验

Experiment on dressing for improving fatigue strengths of welded joints with low transformation temperature electrode

摘要: 焊趾部位存在应力集中和残余拉伸应力,使得接头处的疲劳强度远低于基体金属。通过对纵向环绕焊接接头和横向角接焊接接头试样的疲劳试验表明,低相变点焊条(low transformation temperature electrode,LTTE)熔修是提高焊接接头疲劳强度的有效方法。具体结果是,LTTE熔修的上述两种焊接接头在2×10⁶循环周期下其疲劳强度试验结果分别为154.7 MPa和173.9 MPa,而TIG熔修处理的则分别为152.6 MPa和173.3 MPa,前者分别是后者的101.4%和100.3%。这表明,LTTE熔修方法与TIG熔修方法相当,但前者较后者简单得多,因此LTTE熔修具有极大的推广应用价值。

Abstract: The fatigue strengths of welded joints in welded structures are much lower than those of the base metal because there are stress concentrations and tensile residual stresses at weld toe.Low transformation temperature electrodes(LTTE) dressing is an useful method for improving the fatigue strengths of welded joint.The fatigue tests of LTTE dressing were carried out on both transverse and longitudinal fillet welded joints.At cycles of 2×10⁶,the fatigue strengths of LTTE dressing are 154.7 MPa and 173.9 MPa,respectively,which is 101.4% and(100.3% of) those of TIG dressing.This shows that LTTE dressing in improving fatigue strength is useful or better than TIG dressing,while,LTTE dressing is easier than TIG dressing and it can deal with different position of weld beams.