高温合金激光熔覆过程温度场的数值模拟

在考虑高温合金K417G相变潜热、热物性参数随温度变化、对流与辐射总的换热系数随温度变化的条件下，采用有限元软件ANSYS建立了高温合金激光熔覆动态三维温度场模型。结果表明：在激光熔覆的初始阶段和最后阶段温度迅速上升，中间阶段各个节点有基本相同的热循环曲线，只是时间的先后不同；沿激光束扫描方向和与扫描方向垂直的方向都存在极大的温度梯度，温度梯度的存在引起较大的热应力，而热应力的存在是激光熔覆过程易产生裂纹的主要原因。

Numerical Simulation of Temperature Field During Superalloy Laser Cladding

Three-dimension dynamic temperature field of supemlloy laser cladding was created by ANSYS based on phase-change latent heat, physical property parameter changed with temperature, total coefficient of heat transfer varied with temperature. The results show that temperature rises rapidly at the starting and ending of laser cladding, and in every node in the middle of section, there are the same heat circulatory curves, only the time different.There is unlimited temperature gradient in the direction of laser scanning and vertical laser scanning. Heat stress is caused by temperature gradient, and existence of heat stress is the main reason that cracks is created during laser cladding.