根据合金固液相变多区域性特点（液相区、固相区和糊状区共存），用数值方法求解了适合于多区域相变的单相统一控制方程组，并据此对ｌＣｒ１８ＮｉｇＴｉ不锈钢激光表面重熔熔池的快速凝固过程进行了理论分析．结果表明，凝固过程中液相线的推移速率大大固相线的推移速率，糊状区逐渐扩大；在凝固后期会出现糊状区与团相区共存阶段。 According to the multi-regional characteristics of solid-liquid phase transition (the coexistence of liquid zone, solid zone and mushy zone), the single-phase unified control equations suitable for multi-zone phase transition are solved numerically and the results show that the lCr18NigTi stainless steel The rapid solidification process of laser remelting pool is analyzed theoretically. The results show that during the solidification process, the passing rate of the liquidus greatly changes at the solidus and the mushy zone expands gradually. In the late stage of solidification, the coexistence phase of the mushy zone and the coherent zone occurs.