焊趾TIG熔修对10Ni5CrMoV钢焊接节点疲劳性能的影响

对焊趾氩弧(tungsten-arc inert-gas welding,TIG)熔修与否的10Ni5CrMoV钢大角度焊接节点进行了疲劳试验,比较了相同加载条件下的疲劳寿命、载荷与位移关系及疲劳裂纹启裂位置,同时测量了焊接接头残余应力,并采用有限元计算方法对承载条件下焊接节点的应力应变场进行了分析.结果表明,焊趾TIG熔修显著提高了10Ni5CrMoV钢焊接节点的疲劳性能,在相同承载条件下使焊接节点的疲劳寿命提高了34%.其主要原因在于TIG熔修能有效改善焊趾处的几何形状、降低应力集中程度,从而降低焊趾在承载条件下的应力应变水平,使焊接接头疲劳性能得到提高.

Influence of TIGdressing on fatigue property of 10Ni5CrMoV steel welded joints

The fatigue tests were taken on the large angle welded joints of 10Ni5CrMoV steel with and without tangsten inert gas welding(TIG) dressing treatment on the toe.The fatigue life, the relation of load and stroke and the fatigue crack initiation at the same loading condition were analyzed comparatively.The welding residual stress was also measured.The stress field and the strain field of welded joints with and without TIG dressing treatment were calculated by the finite element method.The results indicate that the TIG dressing treatment can improve the fatigue property of the large angle welded joints of 10Ni5CrMoV steel.The fatigue life of the welded joints is increased 34% by TIG dressing on the toe at the same loading condition.The primary cause is that the TIG dressing treatment can improve the weld geometry and reduce the stress concentration on the weld toe.So the stress value in the toe is reduced at the same loading condition and the fatigue ability of the welded joints is increased.