Abstract

In this paper, Cr12 steel was taken as the research object, and laser micro melting model was established in comsol software based on physical equations such as laser heat source, convection heat transfer, evaporation mobility, recoil pressure, Marangoni effect. The forming mechanism and evolution law of concave–convex microtexture morphology were studied by numerical simulation. The research reveals the changing process of the velocity of the flow field inside the material during the surface deformation. In addition, it can be found from the temperature field changes under different power that the higher the power is, the faster the surface temperature of Cr12 material increases in the process of thermal deformation. And the hardness of the microtexture was greatly improved after the material experienced sudden heat and cold in a very short time. By comparing the numerical simulation results and the experimental results, it can be found that with the increase of power, the height, depth and diameter of the concave–convex microtexture morphology all show an increasing trend, and the surface geometry obtained through numerical simulation matches well with the experimental results. It indicates that the numerical simulation has high feasibility and can effectively reflect the forming process and morphology of concave-convex microtexture.

Graphic Abstract

中文翻译：

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Cr12钢表面激光凹-凸显微组织流场形成的数值模拟和实验研究

摘要

本文以Cr12钢为研究对象，基于激光热源，对流换热，蒸发迁移率，反冲压力，马兰戈尼效应等物理方程，在comsol软件中建立了激光微熔模型。通过数值模拟研究了凹凸微观结构的形成机理和演化规律。研究揭示了表面变形过程中材料内部流场速度的变化过程。另外，从不同功率下的温度场变化可以发现，功率越高，Cr12材料的表面温度在热变形过程中升高得越快。在很短的时间内突然经历热和冷后，显微组织的硬度大大提高。通过比较数值模拟结果和实验结果，可以发现，随着功率的增加，凹凸微纹理形态的高度，深度和直径都呈现增加趋势，并且通过数值模拟获得的表面几何形状匹配。实验结果很好。结果表明，数值模拟具有较高的可行性，可以有效地反映出凹凸形微观纹理的形成过程和形貌。

图形摘要