高强钢低匹配焊接接头应用性能研究  

Practicability Research on Low-match Weld Joint of High-Strength Steel

作　　者：张京海[1] 方大鹏[1] 

机构地区：[1]中国船舶重工集团公司第七二五研究所,河南洛阳471023

出　　处：《材料开发与应用》2012年第3期1-6,共6页Development and Application of Materials

摘　　要：本文采用低匹配焊条材料焊接了高强度钢材,对其焊接接头硬度、强度、抗弯性能、韧性和抗爆性能进行了综合试验研究,研究结果表明,对于屈服强度高达1,000 MPa的钢,其低匹配焊接接头如果采用常规焊缝余高控制工艺,将出现以下不利状况:(1)无余高焊缝金属承受横向拉应力,在母材及HAZ拘束下首先屈服时,发生低延性破坏;(2)有余高焊接接头在弯曲应力及弯曲、拉伸复合作用下,焊接接头易出现焊缝首先塑变破裂的低应力失效现象。其根本原因为焊接接头软质焊缝区塑性变形抗力的不足。此类破坏发生时,钢板尚未充分塑性变形,从承受应力水平和吸收能量能力来看,这将导致焊接接头系统的服役能力大为降低,因此提高低匹配焊接接头焊缝区塑性变形抗力变得极为重要。利用第三强度理论分析了低匹配焊接接头变形特点,并进行了此类接头焊缝余高的特殊设计,获得和传统等强匹配等效的焊接接头,即在服役状态下,确保焊缝金属不先于母材发生塑变集中而失效。In this paper,low-match electrode was employed to weld high-strength steel and a series of tests with the welded joints were conducted including hardness,strength,bend,tenacity and antidetonating quality.The result indicated that for the low-match weld joint of steel with yield strength exceeding 1,000MPa,the conventional control processing of excess weld metal would lead to such undesirable situation:firstly,under tention stress,weld joint without excess weld metal would yield prior to base metal with low ductile fracture accompanying its restrainedly strengthened by higher strength HAZ and base metal,secondly,under bending stress or combined tention with bend,low-stress failure with plastic deformation would occur for the joints with excess weld metal.The essential reason of such situation lays to the insufficient plastic deformation resistence of soft weld.The base metal experienced little plastic deformation when the low-stress low ductile failure occurred in the weld metal,resulting relatively low stress bearing and lower energy absorbing ability,which are undesirable for the capacity of weld joint system in service.So it is very important to increase the plastic deformation resistence of soft weld to avoid plastic deformation concentration in joint.One way is to optimize design excess weld metal of this type joint to obtain equivalent weld joint to conventional full-strength or high-strength match joint,according to maximum shearing sress criterion.

关 键 词：900 MPa焊条 低匹配 余高 韧性 

分 类 号：TG457[金属学及工艺—焊接]