基于边界效应理论的对接焊缝金属断裂特性试验  

Experimental Research on Fracture Properties of Butt-Weldedmetal Based on Boundary Effect Theory

作　　者：李瑶 吕彭民[1] 王斌华[1] 宋绪丁[1] 向清怡 HU Xiaozhi LI Yao;LU Pengmin;WANG Binhua;SONG Xuding;XIANG Qingyi;HU Xiaozhi(Key Laboratory of Road Construction Technology and Equipment,Ministry of Education School of Construction Machinery,Chang'an University,Xi'an 710064,China;School of Mechanical and Chemical Engineering,University of Western Australia,Perth,WA 6009,Australia)

机构地区：[1]长安大学道路施工技术与装备教育部重点实验室,西安710064 [2]西澳大学机械与化学工程学院,澳大利亚珀斯WA6009

出　　处：《机械设计与研究》2022年第5期185-188,194,共5页Machine Design And Research

基　　金：国家科技支撑计划(2015BAF07B02);国家自然科学基金(11902046)资助项目;中央高校基本科研业务费专项资金项目(300102259305)。

摘　　要：焊接作为一种金属连接技术广泛应用于航空、航天、建筑、机械等制造部门。然而在生产过程中,材料化学成分和焊接温度的变化会导致焊缝区城组织的非均质性、非均匀性。焊接完成后,接头处也不可避免.地出现宏微观缺陷,进而造成局部的不连续性。这些特点会直接影响工程结构的使用寿命,其韧脆混合的特性也易导致结构的断裂失效。因此,为探究焊缝金属的断裂特性,文章以Q235B对接焊缝金属为研究对象,通过单边切口三点弯曲试验测得屈服荷载,基于边界效应理论模型确定了对接焊缝金属的断裂韧性K_(IC)及屈服强度σ_(y)。所提模型及方法只需小尺寸对接焊缝金属的三点弯曲试样,研究结果可为确定焊接区域金属材料参数及预测金属结构破坏提供新的参考。Welding as a metal joining technique is widely used in industry such as aviation,aerospace,construction,as well as mechanical engineering.However,during the manufacturing process,the changes in the chemical composition of the material as well as welding temperature can lead to non-homogeneity and heterogeneity in the welded region.Besides,the macro and micro welding defects inevitably appear at welded joints after welding,which leads to geometrical discontinuities in the welded structure.The above characteristics may affect the service life of the structure,and its mixed ductile-britle properties can result in the fracture failure of engineering structures.Therefore,in order to investigate the fracture properties of the weld metal,the hot-rolled carbon steel Q235B buttwelded metal is taken as an example.The material parameters such as fracture toughness K_(IC) and yield strength σ_(y) are determined via the single-sided notched three-point bending(3-p-b)test based on the boundary effect model(BEM).The proposed model and method require only three-point bending specimens of small-size butt-welded metals.The results can provide a reference for determining metal parameters in the weld area and predicting the failure of metal structures.

关 键 词：边界效应模型 对接焊接头 焊缝金属 断裂韧度 屈服强度 

分 类 号：TH140.7[一般工业技术—材料科学与工程]