喷熔修形法提高焊接接头疲劳强度

Modification of Spray Fusing to Improve the Fatigue Strength of Welded Joint

针对工程实际应用的需要,给出了一种提高焊接接头疲劳强度的处理方法.焊接结构中,接头的疲劳强度远远低于母材,其疲劳裂纹主要起源于接头焊趾处.采用Ni60和Fe38两种合金粉末对Q235B钢十字接头焊趾处进行了喷熔修形处理和高频疲劳试验.结果表明,经过喷熔修形处理后,Ni60和Fe38喷熔修形态十字接头的2×106条件疲劳极限分别提高了64.5%和42%.用ANSYS对3种状态接头焊趾处应力集中系数进行计算,结果发现,Ni60和Fe38喷熔修形态十字接头焊趾区的应力集中系数较原始焊态分别减小575.%和37%.

A method was put forward to improve the fatigue strength of welded structure. The fatigue strength of welded joint is far below that of the parent metal and fatigue crack is originated in the weld toe. Two kinds of alloy powder, Ni60 and Fe38, were used to improve the fatigue strength of cruciform joints of Q235B through modification of spray fusing at the weld toe. Results of high cycle fatigue test showed that 2×10^6 offset fatigue strength of the welded joint spray fused by Ni60 and Fe38 increased by 64.5% and 42% respectively compared with that of the aswelded joint. Stress concentration factors were calculated in ANSYS simulation. The results showed that the stress concentration factor of the welded joint spray fused by Ni60 and Fe38 decreased by 57.5% and 37% respectively compared with that of the as-welded joint.