2219T87 鋁合金焊接接頭的常溫蠕變行為及其預測Creep behavior and forecast of welded joint for 2219T87 aluminum alloy at room temperature

研究FSW 和TIG 焊兩種連接態2219T87 鋁合金焊接接頭的常溫蠕變行為，分析焊接工藝和蠕變應力條件對蠕變行為的影響。采用蠕變試驗機考察試件300 h 內的拉伸蠕變和壓縮蠕變性能，并通過實驗數據曲線擬合預測焊接件在1×10⁵h 內相應的蠕變量。結果表明：相同應力水平下，壓縮蠕變量比拉伸蠕變量小。相對于TIG焊，FSW 接頭的質量更好(屈服強度更高)，其顯微組織均勻細小且沒有氣孔缺陷，因此表現出的抗蠕變能力更好。當服役應力低于其屈服強度時，FSW 和TIG 焊接態2219T87 鋁銅合金的1×10⁵ h 蠕變量均不超過1%。

The room temperature creep behavior of 2219T87 aluminum alloy welded joints processed by friction stir welding (FSW) or tungsten inert gas welding (TIG) arc welding was investigated. The effects of welding process and creep stress condition on the creep deformation were analyzed. The tensile and compressive creep properties of the joints in 300 h were real-time measured by the creep machine. Based on the measured data,the creep strain of the joints after 1×10⁵ h was calculated by curve-fitting method. The results show the creep strain of the samples in compressive test is smaller than that in tensile state under the same stress level. In comparison to TIG arc welding,friction stir welding generates better quality joints (with higher yield strength),which possess a fine,homogenous and no pores defect microstructure. Therefore,the FSW joint has a better creep resistance. In addition,when the creep stress is lower than the yield strength,the creep values of the 2219T78 aluminum alloy welded joints processed by FSW and TIG after 1×10⁵ h are less than 1%.

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