摘要
研制一种用于提高焊接接头疲劳强度的新型焊条———低相变点焊条 (LTTE) ,其熔敷金属的马氏体相变温度为 191℃ ,在焊态下 ,LTTE接头纵向焊趾部位获得 -2 5MPa的残余压缩应力。而普通焊条E5 0 15接头相同焊趾部位却为95MPa的残余拉伸应力。利用上述两种焊条分别焊接三种类型的纵向焊接接头 ,并进行疲劳试验。结果证明 ,在 2× 10 6循环次数下 ,LTTE焊接接头的疲劳强度分别比E5 0 15的提高 41%、47%和 5 9% ;在 162MPa的应力幅值下 ,LTTE焊接接头的疲劳寿命分别比E5 0 15的提高 9.9倍、9.6倍和 46.8倍。此外 ,低相变点焊条方法不需增加焊后处理工序 。
A low transformation temperature electrode (LTTE) was developed to improve the fatigue behavior of longitudinal welded joints. The transformation starting temperature from austenite to martensite was about 191℃ for the deposited metal of this welding electrode. At as welded condition, the compressive residual stress at about -25 MPa was obtained at longitudinal weld toe of the joint welded with the developed LTTE, however there is the tensile residual stress at about 95 MPa at the same weld toe of the joint welded with the conventional E5015. The fatigue tests were carried on three kinds of longitudinal welded joints by using above two welding electrodes. The results show that the fatigue strength of the joints welded with LTTE at 2×10 6 cycles were respectively improved by 41%, 47% and 59% compared with that of the joints welded with E5015 and their fatigue life at 162 MPa were respectively improved by 9.9 times, 9.6 times and 46.8 times. Furthermore, the LTTE method is not necessary to add other procedure after welding and so that it can be valuable method to improve the fatigue performance of longitudinal welded joints.
出处
《机械强度》
CAS
CSCD
北大核心
2002年第2期273-276,共4页
Journal of Mechanical Strength
基金
国家自然科学基金资助项目 (50 1 750 79)
关键词
低相变点焊条
纵向焊接接头
疲劳性能
残余压缩应力
Low transformation temperature electrodes (LTTE)
Longitudinal welded joints
Fatigue behavior
Compressive residual stress
