不锈钢焊接凝固裂纹温度场的数值模拟
Numerical Simulation of Temperature Fields for Weld Metal Solidification Cracking in Stainless Steels
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摘要: 进行了不锈钢焊接凝固裂纹温度场分析与数值模拟。首先将电弧看成辐射状对称并呈高斯分布的二维热流作用于工件表面,解决了电弧产热问题;其次,通过液淬法测试金属的固相分数随温度变化率,得到了凝固潜热释放率;最后采用增大热传导系数的方法,考虑了熔池内流体流动对整个温度场的影响。在此基础上,建立了二维焊接凝固裂纹温度场计算模型。此外,采用有限元方法计算了二维焊接凝固裂纹温度场,并研究了焊接规范参数及材料的热物理性能对温度场的影响,为进一步进行焊缝金属凝固裂纹应力应变场的分析奠定了基础。Abstract: In this paper,the temperature field of weld metal solidification cracking in the stainless steel was analyzed and simulated.Firstly,the heat input from the moving arc is assumed to be a radially symmetric Gaussian distribution which is applied on the surface of a workpiece. Secondly, the released latent fusion heat was obtained through measurement of the fraction of solid during welding by means of liquid quench test. Finally, the fluid flow of the weld pool was taken into account by increasing the heat conduction coefficient at elevated temperature. As a result, a 2-D temperature field model for welding solidification cracking was developed. Furthermore, the temperature fields were calculated with finite element method. At the same time, the paper studied influences of welding parameters and thermophysical properties of steels on the temperature fields which laid a foundation for further analysis of thermal stress/strain distributions involving weld metal solidification crack.