装炉温度对大板坯加热过程热应力的影响

A Study of the Effect of Charging Temperature for Thermal Stress of Slab in Heating Process

针对大板坯的加热过程,建立铸坯的热弹塑性模型,研究不同装炉温度条件下铸坯热应力分布的变化规律。研究表明:冷装和400℃装炉的铸坯,表面和心部分别受到压应力和拉应力作用,热应力随加热过程的进行逐渐减小;600,800℃热装铸坯入炉后,表面所受拉应力迅速转变成压应力,峰值最高达37 MPa,心部所受压应力迅速转变为拉应力;出炉之前,热装和冷装铸坯内外的热应力都趋于零。

As to the heating process of slab, thermal elastoplastic mode of the slab was established, thermal stress distribution of the slab were studied under the condition of different charging temperature. Results show that under the condition of cold charge and 400℃ hot charge, the surface and center of slab are effected by the compressive and tensile stress respectively, and the thermal stress decreases with the temperature increase. Under the condition of 600℃ and 800 ℃ hot charge, the tensile stress on the slab surface is quickly converted to the compressive stress with the peak value of 37 MPa, while the compressive stress in the slab center is promptly converted to the tensile stress. Before discharge, the internal and external thermal stresses of the slab are tending to zero both in hot and cold charge.