ASTM A572 Gr65钢焊接接头疲劳断裂表征与评定  

Characterization and Evaluation of Fatigue Fracture of Welded Joints of ASTM A572 Gr65 Steel

作　　者：杨泽源 闫志峰[1] 王树邦 韩明珠 张红霞[1] YANG Zeyuan;YAN Zhifeng;WANG Shubang;HAN Mingzhu;ZHANG Hongxia(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《电焊机》2022年第12期36-42,共7页Electric Welding Machine

摘　　要：ASTM A572 Gr65钢焊接结构件经常要承受动态载荷的作用,接头部位容易发生疲劳失效。在分析ASTM A572 Gr65钢MAG焊接接头力学性能的基础上,结合红外热像法评定了其焊接接头的疲劳性能。结果表明,焊缝区金相组织主要为针状铁素体,其硬度为197~203 HV0.5;焊接接头的屈服强度为350 MPa;在静态载荷和循环载荷下,ASTM A572 Gr65钢焊接接头的表面温度均呈规律性变化,循环载荷下的变形规律与疲劳过程中的温度演化相对应。利用疲劳过程中试件表面的红外温度信息进行评定,疲劳极限为234.18 MPa,与疲劳试验S-N曲线得到的结果(246.60 MPa)相比误差为5.04%;疲劳断裂发生于焊缝区,疲劳裂纹源位于试样内部,呈“鱼眼”状。ASTM A572 Gr65 steel welded structure is often subjected to dynamic loads, and the joints are prone to fatigue failure. Based on the analysis of the mechanical properties of MAG welded joint of ASTM A572 Gr65 steel, the fatigue properties of the welded joint were evaluated by infrared thermography. The results show that the metallographic structure of the weld zone is mainly acicular ferrite, and its hardness is 197~203 HV0.5;the yield strength of welded joints is 350 MPa;the surface temperature of welded joints of ASTM A572 Gr65 steel changes regularly under static load and cyclic load. The deformation law under cyclic load corresponds to the temperature evolution during fatigue. The infrared temperature information on the surface of the specimen during fatigue is evaluated. The fatigue limit is 234.18 MPa, and the error is 5.04% compared with the result of 246.6 MPa obtained from the S-N curve of fatigue test;the fatigue fracture occurs in the weld zone,and the fatigue crack source is located in the interior of the sample, in the shape of "fish eye".

关 键 词：ASTM A572 Gr65钢 MAG焊 红外热像法 S-N曲线 疲劳极限评定 

分 类 号：TG457.11[金属学及工艺—焊接]