HG80钢及其焊接接头的疲劳裂纹扩展

Fatigue Crack Growth of a High Strength Low Alloy Steel HG80 and Welded Joint

为适应大型工程机械焊接用钢需要,对低合金高强度钢HG80及其焊接接头的疲劳裂纹扩展速率进行了研究。结果表明,疲劳裂纹扩展速率对钢板的轧制方向不敏感,焊缝及热影响区疲劳裂纹扩展速率明显低于基材。在排除焊接残余应力导致的裂纹闭合效应后,焊缝及热影响区疲劳裂纹扩展速率与基材相当。

To meet the development of steels used for the large engineering machinery, fatigue crack growth rates of a high strength low alloy steel HG80 and welded joint were investigated. It was found that the fatigue crack growth rates are not sensitive to the rolling direction. Moreover, the fatigue crack growth rates of the weld metal and heat affected zone are lower than those of the base metal. Having excluded the effect of welding residual tresses on crack closure, fatigue crack growth rates of the welded joints are equivalent to those of the base metal.