热轧大型H型钢残余应力相关研究

在全轧程热力耦合计算结果的基础上,对大型H型钢冷却后的残余应力场进行仿真分析。得到了沿着长度方向大型H型钢腿腰连接部位及翼缘整体表现为拉应力、腹板为压应力的残余应力场计算结果。H型钢冷却过程中,腹板的残余压应力有可能导致腹板冷却波浪的产生。对使用过程中切割翼缘时残余应力场的转变过程进行仿真分析,得到当切口到达H型钢腿腰连接部位时,切口处拉应力突然增大的结果。切口处应力场的突然变化与腹板开裂直接相关,H型钢腹板的开裂属于脆性断裂。对控制大型H型钢残余应力的方法进行仿真研究,得到了通过翼缘外侧强制冷却改善残余应力分布的结果。

Research of residual stress in hot rolled large size H-beams

Due to the complexity of cross-section,the finish rolling temperature distribution is uneven and causes complex residual stress distribution in hot rolled large size H-beam.3D numerical simulation of the residual stress distribution of hot rolled H-beams after cooling and the residual stress transformation during flange cutting had been accomplished,with the simulation result of the whole rolling process being used as the initial thermal field.The residual stress appeared as tensile stress in connection area and flange and as compressive stress in web along the length direction.During the flame cutting process,tensile stress increased suddenly when the kerf arrived at the position of leg-waist connection that may cause brittle fracture of the H-beam web.The method of controlling the residual stress had been achieved through numerical simulation.The simulation results show that the distribution of residual stress could be improved with forced cooling on the out side of the flange,significant effects have been derived in the practical application.