1Cr18Ni9Ti不锈钢焊接熔池的组织模拟

Microstructure simulation in welding lCrl8Ni9Ti steel

运用晶界演化Grain boundary evolution模型,利用PHOENICS软件计算在不同焊接参数下1Cr18Ni9Ti不锈钢TIG焊接温度场,采用VB语言编制程序模拟了焊缝中柱状晶的生长。结果表明,熔池形状和尺寸影响了柱状晶的生长方向,熔池长宽比越大,晶粒的生长方向越垂直于焊缝中心,晶粒短而直;长宽比越小,熔池形状越接近圆形,晶粒的弯曲程度越大,晶粒长而弯。Grain boundary evolution模型能准确地模拟不锈钢焊缝中柱状晶的生长形态,与试验结果中的柱状晶的生长形态吻合较好。

The growth of columnar grain during the solidification of the 1Cr18Ni9Ti stainless steel weld metal for different welding parameters is simulated using the grain boundary evolution (GBE) modeling method. The shape and the size of the weld pool under different welding parameters are calculated using PHOENICS software. The simulated results show that the growing direction of the columnar grains is dependent on the shape of the weld pool. The straight and short grains tend to grow in direction perpendicular to the weld cen-terline if the length/width (L/W) of the weld pool is large and the curving and long grains grow toward the welding direction if the L/W ratio is small. The experimental results are found to be in good qualitative agreement with the simulated results.