loading980MPa级低碳贝氏体高强钢MAG焊接接头不同试样的
拉伸断裂机理
张晓波;曹睿;彭云;杜挽生;田志凌;陈剑虹
【期刊名称】《机械工程材料》 【年(卷),期】2012(036)002
【摘要】Tensile tests were applied to five kinds of specimens with different shapes and notch poisitions in the MAG welded joint of 980 MPa low-carbon bainite high strength steel used for deep-sea.The dynamic fracture process of every kind of specimens was in-situ observed to analyze the fracture mechanism,and to determine the week part of joint.The results show that the fracture of straight notch specimens
suffered
the
process
of
plastic
deformation,initiating,propogation,blunting and fracture of cracks.The crack tip repeatedly blunted,prapogated,new cracks initiated,re-blunted,re-propagated during crack propogation.The arc and flat specimens fractured in a shear mode and suffered the process of plastic deformation,necking,initiation,propagation
and
fracture
of
microracks.The weak part of all specimens was the weld metal.%在980MPa级深海用低碳贝氏体高强钢MAG焊接接头上,制取5种不同形状和缺口位置的试样进行拉伸试验,原位观察了每种试样的动态断裂过程,并对其断裂机理进行了分析,确定了焊接接头的薄弱部位。结果表明：直缺口试样的断裂经历了塑性变形、裂纹起裂、裂纹扩展、裂纹尖端钝化,直至断裂的过程,并且在裂纹