Q235B焊接接头超高周疲劳性能  

Super High Cycle Fatigue Properties of Q235B Steel Welded Joint

作　　者：吴良晨[1] 王东坡[1] 王康[1] 邓彩艳[1] 刘哲[2] 

机构地区：[1]天津大学材料科学与工程学院,天津300072 [2]中国石油管道研究中心,廊坊065000

出　　处：《天津大学学报》2008年第12期1480-1484,共5页Journal of Tianjin University(Science and Technology)

基　　金：国家自然科学基金资助项目(50405019);天津大学博士后基金资助项目(20070420696)

摘　　要：用超声疲劳试验装置对Q235B母材及焊接接头试件进行超声疲劳试验,研究其在超高周疲劳寿命区间的疲劳性能.加载频率为20 kHz,应力比R=-1.采用国际焊接学会制定的统计方法处理试验数据.试验结果表明,在107～109循环周次内,Q235B母材和焊接接头仍然发生断裂,其S-N曲线都是连续下降的;传统疲劳概念上的疲劳极限并不存在.研究结果表明,使用5×106循环周次下的疲劳数据去设计超高周疲劳寿命的焊接结构是很危险的.Ultrasonic fatigue tests were carried out on Q235B base metal and welded joints by an ultrasonic fatigue test equipment in order to investigate their super high cycle fatigue properties. The cycling frequency was 20 kHz and the stress ratio R is -1. Statistical method established by International Institute of Welding was used to process test data. The results show that during 10^7-10^9 cycles, fracture can still happen on Q235B base metal and welded joints, and the S-N curves descend continuously; there is no fatigue limit as the traditional fatigue conception describes. Consequently, as for Q235B structures, it is dangerous to use the data under 5×10^6 cycles for their super high cycle fatigue design.

关 键 词：超高周疲劳 焊接接头 超声疲劳试验 

分 类 号：TG404[金属学及工艺—焊接]