中低强度钢超声冲击处理焊接接头热点应力设计曲线  

Hot spot stress design S-N curve of ultrasonic impact treated welded joints of medium and low strength steel

作　　者：胡会会[1] 王东坡[1] 吴良晨[1] 邓彩艳[1] 

机构地区：[1]天津大学天津市现代连接技术重点实验室,天津300072

出　　处：《焊接学报》2016年第5期124-128,134,共5页Transactions of The China Welding Institution

摘　　要：用ANSYS计算了对接接头、横向非承载十字接头和纵向非承载角接板的热点应力集中系数Khs,根据Q235B和Q345B的超声冲击处理焊接接头的相关疲劳试验数据得出经过应力比、板厚和几何不平度修正后的超声冲击处理焊接接头的热点应力设计S-N曲线.结果表明,经过超声冲击处理后,中低强钢(Rm≤355 MPa)对接接头、横向非承载十字接头和纵向非承载角接板的热点应力S-N曲线的分散性降低,与接头形式无关,可以用一条热点应力设计S-N曲线表达.在采用热点应力法进行疲劳设计时,选取m=10.0,上述三种类型焊接接头在2×106次疲劳强度级别可统一采用FAT135来表示.First,the hot spot stress concentration factor( Khs) of butt joints,transverse non-load-carrying cruciform joints and non-load-carrying longitudinal fillet plate joints are calculated using ANSYS. Then,according to the relevant fatigue tests results of ultrasonic impact treated welded joints of Q235 B and Q345 B,the corrected hot spot stress design S-N curve by stress ratio,thickness and geometric irregularities of ultrasonic impact treated welded joints is obtained. Analysis shows that the dispersion of data points of the hot spot stress design S-N curve of ultrasonic impact treated butt welds,transverse non-load-carrying cruciform joints and non-load-carrying longitudinal fillet welds of medium and low strength steel reduced and can be expressed with one design S-N curve independent of the form of joint. The recommended m = 10. 0 is also applied for hot spot stress fatigue design and the fatigue strength level of the three types of welded joint above-mentioned can uniformly applied to FAT135 at 2 ×106 times.

关 键 词：热点应力 疲劳强度 超声冲击 

分 类 号：TG404[金属学及工艺—焊接]