论文部分内容阅读
通过对焊接熔池流体流动与传热过程控制方程组、合金元素气化方程、Ｍａｒａｎｇｏｎｉ力方程以及其他辅助方程的耦合求解，定量计算了ＦｅＣｒＮｉＳ合金系中具有不同Ｓ含量时焊接熔池的表面温度分布和浮力、电磁力、Ｍａｒａｎｇｏｎｉ力共同作用下的表面速度分布．结果表明，在微量的Ｓ含量条件下，熔池表面上的Ｍａｒａｎｇｏｎｉ力会出现一个最大值．随Ｓ含量增大，Ｍａｒａｎｇｏｎｉ力减小，Ｍａｒａｎｇｏｎｉ力的最大值对应的温度增大．在Ｍａｒａｎｇｏｎｉ力诱导下，熔池内会形成两个方向相反的涡流环路，它们具有不同的温度，并在熔池表面上逆向而流，相遇处产生很大的温度梯度，从而在该部位引发表面速度奇异峰值．当Ｓ含量较小时，表面速度奇异峰值发生在液相线前沿，当ｗ（Ｓ）大于０．０３％时，速度奇异性消失．
Through the coupled solution to the control equations of fluid flow and heat transfer process in weld pool, the alloying element gasification equation, the Marangoni force equation and other auxiliary equations, the content of S in the FeCrNiS alloy system is calculated quantitatively Surface temperature distribution of weld pool and surface velocity distribution under combined action of buoyancy, electromagnetic force and Marangoni force. The results show that there is a maximum of Marangoni force on the surface of molten pool under the condition of trace S content. As the content of S increases, the Marangoni force decreases and the maximum temperature of Marangoni force increases. Under Marangoni force induction, two vortex loops of opposite directions are formed in the weld pool, which have different temperatures and reversely flow on the surface of the weld pool, resulting in a large temperature gradient at the weld, causing the surface at this site Fantastic speed of the peak. When the content of S is small, the singular peak of surface velocity occurs on the front of the liquidus. When w (S) is more than 0.03%, the velocity singularity disappears.