【摘要】 本文用扫描电镜、电子探针、俄歇电子能谱和X射线方法对激光表面合金化层出现的一条抗腐蚀性能良好的"白亮带"进行了全面的分析和讨论。结果表明"白亮带"是由于熔体开始凝固时温度梯度对凝固速度比值G/R达到平面状向前推移的条件下形成的。结晶相是单相固溶体时,"白亮带的宽度随溶质浓度Coo的增加而变窄,而且与基体晶粒相连。由于某些组元存在着成分梯度,致使合金化层的相组成在定量分配上存在着一定的梯度。更多还原

【Abstract】 The bright zone with high corrosion resistance appeared in the laser melting alloying layer has been studied by means of SEM, EP, AE and X-ray analyses. The obtained result shows that the bright zone forms when the ratio of temperature gradient to solidification rate, i. e. G/R, for crystal planefront growth is satisfied as the solidification of the. layer is started. The bright zone is a single phase solid solution which grows continously from matrix grains,and its width becomes as the solution concentration (Coo) increases.Due to the gradient of alloy concentration, the phase constitution of the laser alloying layer exhibits also certain gradient in its quantitative distribution.更多还原