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以合金相交多区域统一模型为基础，利用数值模拟方法，对脉冲Ｎｄ：ＹＡＧ激光表面熔凝过程的非稳态温度场和熔区内的流场进行了理论分析。能量方程求解中考虑了固液相变潜热的吸收与释放；合金元素气化热损失、自然对流与辐射热损失；动量方程求解中考虑了热表面张力与浮力联合驱动流。结合实验条件计算了１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢在低频脉冲熔凝情况下熔区的形状和尺寸，并与实验解剖进行了比较。结果表明，在占空比较小时，系列脉冲中每一脉冲形成的表面熔区形状和尺寸可用定点轴对称脉冲模型很好地近似。
Based on the unified model of multi-zone alloy intersection, the unsteady temperature field and the flow field in the molten zone of the pulsed Nd: YAG laser surface are theoretically analyzed by numerical simulation. The energy equation solves the absorption and release of the latent heat of solid-liquid phase transformation, the heat loss of gasification of alloying elements, the natural convection and the radiative heat loss. The thermal surface tension and buoyancy-driven flow are considered in the momentum equation. The shape and size of 1Cr18Ni9Ti stainless steel in the condition of low frequency pulse melting were calculated with experimental conditions and compared with experimental anatomy. The results show that at smaller duty cycles, the shape and size of the surface melt zone formed by each pulse in a series of pulses can be well approximated by a fixed-axis symmetrical pulse model.