第三类边界条件下大型圆柱体钢锭加热的应力模型

Stress model of large cylindrical ingot heating under third boundary condition

根据传热学原理,从钢锭在第三类边界边界条件下的温度计算模型出发,结合钢锭的弹性模量、泊松比和线膨胀系数建立了钢锭加热过程的热应力变化模型,模型计算表明:在钢锭的表面与中心温差达到最大时,轴向应力峰值在钢锭表面达到最大正值,在钢锭中心达到最大负值,随后逐渐减小;切向应力和径向应力在钢锭的表面有最大应力峰值生成,从表面到中心,应力逐渐减小,在中心处,应力值为0。随加热时间的延长和表面温度的升高,钢锭表面与中心温差值的减小,轴向应力、切向应力和径向应力都变为0。模型为常温钢锭安全加热过程的炉温参数设置提供了理论依据。

According to the principle of heat transfer, starting from the ingot in the third boundary conditions of temperature calculation model, combined with the ingot elastic modulus, Poissons ratio and the coefficient of linear expansion of the heating process of ingots, the thermal stress change model was set up. The model calculation shows that when the temperature difference in the surface and the center of the ingot reaches the maximum, the axial stress reaches the maximum positive value in the ingot surface, reaches the maximum negative value in the ingot center, and then decreases gradually; the tangential stress and radial stress reach the maximum peak in the ingot surface, from the surface to the center, stress reduces to 0 gradually. With the increase of elongation of the heating time and surface temperature, the ingot surface and center temperature difference are reduced, and the axial stress, circumferential stress and radial stress are changed to 0. The model provides theoretical basis for the parameters setting in ingot safely heating process at room temperature.