A557焊条填充10Ni5CrMoV钢接头熔合区的凝固组织研究

Solidification Structure of Fusion Zone of 10Ni5CrMoV Steel Joints Filled with A557 Electrode

采用光学显微镜、显微硬度计和扫描电镜+X射线能谱仪研究了A557焊条填充10Ni5CrMoV钢接头熔合区的凝固组织。结果表明:只有微分干涉相衬法光学金相才清晰地显示了熔合区扩散过渡层存在白亮、光滑、无胞状柱状凝固特征的"白亮带"和具有胞状凝固特征的后续熔化滞留层。"白亮带"是平面生长形成的"平面晶",它是在温度梯度较大、生长速度较低时出现,其显微组织为单相奥氏体。后续熔化滞留层是胞状生长凝固形成的,且有较多的合金元素扩散进入该层,但没有对流传质,这充分说明该层的后续熔化和滞留行为。

Solidification structure of the fusion zone of the l 0Ni5CrMoV steel joints filled with A557 electrodes was studied by using OM, microhardness tester and SEM additional X-ray energy dispersive spectrometer. The results show that ＂the bright band＂ and ＂follow-up melted stagnant layer＂ are clearly observed only with differential interference contrast and has bright and no cellar-columnar. ＂The bright band＂ is ＂planar crystal＂ which is planar growth forming, its microstructure is single phase austenite.Under big temperature grads and low growth rate, the plane growth comes into being in ＂diffusion transition layer＂ and ＂the bright band＂ forms. Cell growth occurs in ＂follow-up melted stagnant layer＂ and plentiful alloy atoms enter into the layer by diffusion but convection, which explains ＂follow-up melted＂ and ＂stagnant＂ action of the layer adequately.