借助于LS-DYNA有限元软件,在H型钢轧制全程有限元分析的基础上,对轧后H型钢空冷过程进行了三维热力耦合有限元分析,分析了不同热定尺情况下H型钢残余热应力的分布.结果表明:该热轧H型钢因轧后断面温度场的分布不均匀导致空冷过程中残余热应力的分布状态复杂,其中沿轧件长度方向上的残余热应力在腹板部位整体表现为压应力,可达160 MPa以上,而翼缘中心和腰腿连接部位表现为拉应力;H型钢宽度方向的残余应力影响长度方向上的应力分布,当采用热锯定尺小于3 m时,随着长度的减小沿长度方向的残余热应力相应减小.

Commercial FEM program LS-DYNA has been used to do the simulation of thermal residual stress in H-beam’s air cooling,with the thermal mechanical coupled method and the whole rolling process simulation result used as the initial thermal field.The residual stress field results of H-beam in different lengthes have been obtained.The simulation results show that the residual stress condition was complicated by the ununiformity of cross section’s thermal field.In the direction of length,the residual stress at the web manifested compressive stress and in the whole could reach 160 MPa,while that at the web center and at the connect position betweeen web and flange manifested tensile stress.The residual stress condition in the direction of width influenced the distribution of the residual stress in the direction of length.While the length was less than 3 m,the residual compressive stress decreased as the hot cut length was shortened.