基于多指标综合评分方差分析的镍铬合金储能缝焊工艺研究

Study on Condenser Discharge Seam Welding Technology of Nickel-Chrome Based on Variance Analysis of Multi-index Comprehensive Score

以接头的拉剪力、重叠量和焊透率的加权综合评分值为检测质量指标,对0.5 mm厚的Cr20Ni80镍铬合金进行了储能缝焊(CDSEW)试验,采用多指标综合评分方差分析法(ANOVA)研究了焊接速度、放电频率和储能量对缝焊接头质量的影响,并对试样进行了金相观察。结果表明:焊接速度对镍铬合金储能缝焊接头质量影响显著,储能量对其影响比较显著,但影响程度低于焊接速度,而放电频率对接头质量无显著影响,焊接速度越大,失效能量越小,接头的塑性变形能力越差。最优工艺组合下三指标检测量的综合评分值为0.978,对应的拉剪力为4.971 kN,重叠量为45.8%,焊透率为63.7%。镍铬合金在缝焊过程中未发生相变,整个接头全为单相奥氏体固溶组织,焊缝熔核区组织均匀,晶粒以树枝状分布。

The condenser discharge seam welding(CDSEW)experiment of Cr20Ni80 nickel chrome alloy with thickness of 0.5 mm was carried out by taking the weighted comprehensive score of tensile shear force,overlap and penetration rate of the joint as the quality index.The influence of welding speed,discharge frequency and energy storage on the quality of seam welding joint was studied by multi-index comprehensive score analysis of variance(ANOVA),and the specimen was observed by metallography.The results show that the welding speed has a significant impact on the quality of nickel chrome alloy CDSEW joint,and the energy storage has a certain effect on the joint quality,but the discharge frequency has no significant impact on the quality of the joint.The higher the welding speed,the lower the failure energy and the worse the plastic deformation ability of the joint is.Under the optimal process combination,the comprehensive score value of three indicators is 0.978,corresponding tensile shear force is 4.971 kN,overlap is 45.8%,and penetration rate is 63.7%.There is no phase transformation in the weld process of nickel chrome alloy,the whole joint is single-phase austenite solid solution structure,the weld nugget zone is uniform and the grains are distributed in dendrite.