NUMERICAL SIMULATION OF TEMPERATURE FIELDS FOR WELD METAL SOLIDIFICATION CRACKING IN STAINLESS STEELS

This paper has analyzed the influences of the heat input of welding arc, the latent heat of solidifica- tion,fluid flow of liquid metal on the heat conductivity pertaining to welding solidification crack of stainless steels. As a result,two - dimensional heat conduction models with prescribed heat flux mov- ing along the the have been developed that can simulate welding arc, convection and radiation heat loss from top and bottom surfaces of the workpiece. Finally, the finite element model was used to ana- lyze and calculate the temperature field.

Numerical simulation of temperature fields for weld metal solidification cracking in stainless steels

This paper has analyzed the influences of the heat input of the welding arc, the latent heat of solidification, the fluid flow of liquid metal on the heat conductivity pertaining to the welding solidification crack of stainless steels. As a result, two dimensional heat conduction models with the prescribed heat flux moving along the weld have been developed that can simulate welding arc, convection and radiation heat loss from top and bottom surfaces of the workpiece. Finally, the finite element model was used to analyze and calculate the temperature fields.

不锈钢焊接凝固裂纹温度场的数值模拟

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。

C45Cr钢连铸大断面圆坯凝固过程数学模拟

通过控制大断面圆坯的凝固过程控制最终连铸坯质量,基于薄片移动边界法建立了连铸大断面圆坯的凝固传热数学模型。应用Pro CAST软件对C45Cr钢、直径为准650 mm连铸圆坯凝固过程进行了数学模拟,计算出大断面圆坯凝固过程的温度场,并且得到铸坯的固相率分数与液芯长度。模拟结果表明,铸坯表面温度模型预测结果与工业试验测温结果吻合很好,所以此数学模型计算结果能够准确地反映实际情况。讨论了过热度、拉速、二冷强度等因素对大断面圆坯表面温度、中心温度、固相率分数以及液芯长度的影响,为连铸工艺参数的优化及凝固末端电磁搅拌位置的确定提供了有效指导。

齿轮钢20CrMnTi方坯凝固过程传热数值模拟

基于薄片移动边界法建立200 mm×200 mm方坯凝固过程传热数学模型,通过商业软件ProCAST对方坯20CrMnTi的温度场进行数值模拟,计算出了热物性参数。将工业现场实测的铸坯表面温度与模拟结果进行比对分析,其误差在工程误差允许范围(5%)内,因此,本数学模型能够较准确地反映现场的实际生产情况。在此模型的基础上讨论了不同过热度、拉速、二冷水量对方坯表面温度、中心温度、中心固相率及液芯长度的影响,对连铸工艺参数的优化提供有效指导。