超长寿命区间16Mn钢焊接接头疲劳性能  

Fatigue properties of welded joints of 16Mn steel in super long life region

作　　者：吴良晨[1] 王东坡[1] 邓彩艳[1] 王康[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《焊接学报》2008年第3期117-120,共4页Transactions of The China Welding Institution

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

摘　　要：使用自行研制的TJU—HJ—I型超声疲劳试验系统装置进行了16Mn钢母材和焊接接头试件的超声疲劳性能试验，以探索其在超长疲劳寿命区间的疲劳行为。结果表明，无论母材还是焊接接头，其S—N曲线都是一条连续下降的曲线；在10^6～10^7循环周次范围内焊接接头不存在传统概念上的疲劳极限，载荷循环周次超过10^7甚至10^9以后，试件依然发生疲劳断裂。在超长寿命区间，焊接接头疲劳强度远低于母材的疲劳强度。使用现有疲劳极限数据去设计工作在超长寿命区间的焊接结构件是很危险的。Ultrasonic fatigue properties experiments have been performed with base metal and welded joints of 16Mn steel using a home-made ultrasonic fatigue testing system. The objective was to investigate its fatigue behaviors of welded joints in super long life region. The cycling frequency is about 20 kHz and the load ratio is -1.The testing results show that the S-N curves of both base metal and welded joints are not horizontal in super long life region. The specimens still fail over 10 7, even 10 9 stress cycles and there is no fatigue limit between 10 6 and 10 9 cycles. The fatigue strength of welded joist is much less than that of base metal. It is dangerous to design the super long life welded structures by c urrent fatigue data. It is necessary to carry out comprehensive research of welded joints in super long life region with different material and different joint style.

关 键 词：超长寿命 焊接接头 疲劳性能 超声疲劳试验 

分 类 号：TG404[金属学及工艺—焊接]