Laser polishing, as an effective surface finishing process, is significantly affected by ambient gas. Previous studies on the contribution of ambient gas to laser polishing mostly focused on experiments, but rarely on numerical simulations. Given this, this paper proposes an improved model capable of analyzing the effects of ambient gas on the laser-polished surface's morphology evolution mechanisms, by expanding an existing laser polishing model with the influences of mass transfer, solutocapillary forces, and chemical reactions. Argon and air were used as ambient gasses for comparison. Through this model, the surface morphology evolution of laser polishing in air was compared with that in argon in terms of the velocity field, temperature field, concentration field, melt surface velocity, molten pool surface profile, and surface forces. The respective contributions of chemical reaction heat, oxygen mass flux, mass transfer, and surface forces were also presented. Furthermore, the numerical model was verified on 304 stainless steel from the perspectives of polished surface roughness, molten pool depth, and oxygen element distribution.

激光抛光作为一种有效的表面精加工工艺，受环境气体的影响很大。以往关于环境气体对激光抛光的贡献的研究大多集中在实验上，而很少涉及数值模拟。鉴于此，本文提出了一种改进模型，该模型通过扩展现有的具有传质、溶液毛细管力和化学反应影响的激光抛光模型，能够分析环境气体对激光抛光表面形貌演化机制的影响。氩气和空气被用作用于比较的环境气体。通过该模型，从速度场、温度场、浓度场、熔体表面速度、熔池表面轮廓和表面力等方面比较了空气中激光抛光与氩气中激光抛光的表面形貌演变。还介绍了化学反应热、氧气质量通量、传质和表面力的各自贡献。此外，从抛光表面粗糙度、熔池深度和氧元素分布等角度对 304 不锈钢的数值模型进行了验证。