高温焊接对1.25Cr0.5Mo焊接构件疲劳寿命的影响

选取不同的温度(550,650,750,850℃)对1.25Cr0.5Mo钢进行高温焊接,在高温焊接及常温焊接后对焊件进行残余应力测试和疲劳试验.结果表明,550,650,750,850℃高温下焊接的试件,其焊缝热影响区的残余应力最大值(纵向、横向)比常温下焊接焊缝热影响区残余应力最大值(纵向、横向)都显著降低:纵向和横向降低幅度分为50.1%,48.9%;74.8%,67.4%;83.9%,79.4%;91%,89.7%.高温焊接试件的疲劳寿命的平均值比常温下焊接试件疲劳寿命的平均值分别提高31.02%,38.84%,47.23%和62.28%.结果表明,高温焊接能明显降低焊件的残余应力和提高焊件的疲劳寿命.

Effect of high-temperature welding on fatigue life of 2.25Cr1Mo steel joint

High-temperature welding of 1.25Cr0.5Mo steel at different temperatures (550℃, 650℃, 750℃ and 850℃) was carried out. Residual stress measurement and fatigue experiments were done after welding at room and high temperatures, respectively. The maximum longitudinal and transverse residual stresses in heat-affected zone of high-temperature welded specimens were significantly reduced, comparing to those at room temperature, the reduction rate for longitudinal and transverse residual stress was 50.1%, 48.9%, 74.8%, 67.4%, 83.9%, 79.4%, 91% and 89.7%, respectively. The average fatigue life was improved 31.02%, 38.84%, 47.23% and 62.28%, respectively. The results show that high- temperature welding can significantly reduce residual stress and improve the fatigue life of the welded joint.