不锈钢重熔工艺瞬态热物理性能数值模拟

Numerical Simulation of Transient Thermal Features in the Remelting Processing of Stainless Steel

应用有限元方法对层流等离子体射流不锈钢表面重熔工艺中的瞬态热物理现象进行了数值模拟研究.针对不同加热距离,确定了材料熔化和凝固过程中的瞬态温度场、温度梯度和凝固率的时间和空间分布特征.通过引入等效温度面积密度概念,研究了不锈钢重熔热处理的适合条件.结果表明,9～13 mm的范围是较为适宜的加热距离,该结果与试验观察基本符合.

A two-dimension model was established based on the experimental results of the laminar plasma remelting processing on the stainless steel.The main purpose is to determine the proper processing conditions of material surface heat treatment through the finite element simulation.The related results include the determination of the variations of the temperature,the temperature gradients and the cooling rates of the pool substances with time.A criterion based on the concept of the equivalent temperature area density （ETAD） is established to predict the proper processing conditions for the situation of the stainless steel remelting.Theoretically,the method can be used to determine the optimum processing condition of heat treatments and equally generalized to the cladding treatment situations of both the plasma processing and the laser technology.The simulating results show that the appropriate heating distances should be in the region of 9-13 mm for the laminar plasma processing,which is in agreement with the experimental observation.