超声冲击处理对大厚度高强钢焊接接头抗拉强度的影响

摘要

Firstly,two EQ56 high strength steel plates with 45 mm thickness were welded by butt welding, and then ultrasonic impact treatment (UIT)was carried out on the top and bottom surfaces of the welded joint.At last,tensile strength of the welded joint in different positions was measured with the small shear punch method,and the effect of UIT on tensile strength of the welded joint was investigated.Research results show that,the tensile strength distribution within the large-thickness high-strength steel welded joint are not uniform along the thickness and transverse directions;after UIT,the tensile strength of the treated region decreased within a depth of about 3-1 8 mm distance from the top and bottom surfaces,this is due to the internal material softening caused by UIT;in addition,with the increase of the depth from the surfaces,the softening effect decreased.%首先将两块45 mm厚EQ56高强钢板进行对接焊，然后对焊接接头的上下表面进行超声冲击处理，最后采用微冲剪方法对接头不同位置的抗拉强度进行测试，研究了超声冲击处理对接头抗拉强度的影响。结果表明：大厚度高强钢焊接接头的抗拉强度在横向和厚度方向都分布不均匀；超声冲击处理可使内部材料发生软化，造成冲击区域距上下表面3~18 mm深度范围内材料的抗拉强度降低，并且距表面深度越大，软化效应越不明显。