层流冷却过程中热轧带钢的应力及计算机仿真

Stress of Hot Rolled Strip Steel in Laminar Cooling Process and Computer Simulation

以Q235B带钢层流冷却过程为研究对象,建立了冷却过程的数学模型。通过FLUENT仿真得到了带钢表面不同位置的对流换热系数。采用ANSYS和MATLAB软件对带钢冷却过程中的温度变化、相变和应力分布进行了仿真。结果表明:水冷过程中,带钢上下表面的温度变化成锯齿状,中心温度基本是线性降低;冷却结束后,主要成分为铁素体,上表面的铁素体含量为93.2wt%;在水冷阶段,带钢应力急剧增加且呈锯齿状,在空冷阶段应力下降,冷却结束后,上下表面和中心的应力基本相等;后段主冷模式与前段主冷模式相比,Q235B带钢上下表面和中心位置的平均应力分别降低了47.6%、29.4%、11.2%。

Taking Q235B strip steel laminar cooling process as the research object, the mathematical model of the cooling process was established. The convective heat transfer coefficients of the strip steel surface in different locations were obtained by FLUENT simulation. The temperature change, phase transformation and stress distribution in cooling process were simulated by using ANSYS and MATLAB software. The results show that, in water cooling process, the temperature change of the strip steel on upper and lower surfaces is toothing, and the central temperature linear decreases basically. The main component after cooling is the ferrite, and the ferrite content on the upper surface is 93.2wt%; in water cooling stage, the stress of the strip steel is sharp increase and jagged. In air cooling stage the stress decreases, and the stresses on the upper and lower surface and the center are nearly equal after cooling; compared with the main cold mode and anterior posterior segment of main cooling mode, the average stresses of Q235B strip steel on upper, lower surfaces and a central location decrease by 47.6%, 29.4% and 11.2% respectively.