La和Ag对石油钻杆用Weldalite049铝合金热稳定性的影响

Effects of La and Ag on Thermal Stability of Weldalite049 Alloy used forOil Drilling Rod

摘要:

通过对Weldalite049铝合金挤压棒材采用T6峰时效处理,利用SEM、TEM及拉伸性能检测,研究稀土元素La和Ag的不同配比在热处理后以及不同的热暴露条件下对Weldalite049铝合金石油钻杆的显微组织和拉伸性能的影响。其目的是研究在满足力学要求的前提下,用少量稀土La替代价格较高Ag的方法。实验结果表明,用0.05wt.%La取代0.2wt.%Ag的049合金经T6处理后其抗拉强度为615.5MPa,高于Weldalite049合金611.1MPa的抗拉强度；添加0.1wt.%La而无Ag的049合金在175℃/60h的热暴露条件下的力学性能仍能保持在一个较高的水平(σ_b≥530MPa、σ_0.2≥480MPa、δ≥7％)。

Abstract:

The influence of different ratios of La and Ag under the condition of T6 peak aging treatment and different thermal exposure were investigated. The microstructures and tensile properties of Weldalite049 aluminum alloy were analyzed by SEM, TEM and tensile properties testing. The aim is to investigate the method of substituting a small amount of rare earth La for higher price Ag in precondition of satisfying mechanical requirements. It is proved that the tensile strength of Weldalite 049 alloy with 0.05wt.% La instead of 0.2wt.% Ag is 615.5MPa after T6 treatment, which is higher than that of Weldalite 049 alloy 611.1MPa. The mechanical properties of Weldalite 049 alloy with 0.1wt.% La but without Ag remain at a high level under thermal exposure at 175 C/60h.