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采用电子束焊接了镍基C-276合金棒,在500~650℃条件下进行了高温拉伸性能测试,并对焊接接头进行了600℃、300h的等温模拟试验及显微组织分析.结果表明:焊接接头的强度随测试温度的升高而逐渐降低,其屈服强度高于或者接近母材的屈服强度,但是最高断裂强度只达到母材的70%,延伸率也大大低于母材;经等温处理后,焊接接头600℃下的屈服强度和断裂强度均明显提高,延伸率略有改善;焊缝熔合区的显微硬度大于母材,且经等温处理后,熔合区的硬度更高;焊缝熔合区中形成的细小板条组织起到硬化作用;600℃等温处理过程中有沉淀相析出,起到沉淀强化的作用.
The Ni-based C-276 alloy rod was welded by electron beam and the tensile test was carried out at 500-650 ℃, and the isothermal simulation test and microstructure analysis of the welded joint at 600 ℃ and 300h were carried out. : The strength of welded joint decreases with the increase of the test temperature, the yield strength is higher than or close to the yield strength of the base metal, but the maximum breaking strength reaches only 70% of the base metal and the elongation is also much lower than the base metal; After isothermal treatment, the yield strength and the rupture strength of the welded joint at 600 ℃ are obviously improved and the elongation is slightly improved; the microhardness of the weld zone is larger than that of the base metal, and the hardness of the welded zone is higher after isothermal treatment; The microstructure of the fine lath formed in the fusion zone of the weld plays a role of hardening; precipitated phase precipitates during the isothermal treatment of 600 ℃, which plays the role of precipitation strengthening.