【摘要】 利用轧后余热对H型钢进行在线热处理,既能提高强度,又可以节约能源。但是由于H型钢结构复杂,导致其轧制后冷却不均匀,从而产生过大的残余热应力。喷嘴位置固定,采用Fluent软件数值仿真,研究了气雾冷却过程中700×350 H型钢不同部位的表面换热系数,得出,随着气压的增大,换热系数增大,但喷嘴流量和直径对换热效果的影响没有一定规律。在此基础上,又优化了气雾喷射参数,分析了几种工况下的温度场,最终得出,在水流量L1=0. 05 kg/s、L2=0. 1 kg/s、L3=0 kg/s,喷嘴气压为0. 3 MPa的条件下,700×350 H型钢的温度场最为均匀。更多还原

【Abstract】 The on-line heat treatment of H-beam steel by using residual heat after rolling can not only increase the strength,but also save energy. However,complex configuration of the Hbeam steel will result in its uneven cooling and therefore development of excessive residual thermal stress after rolling. Surface heat transfer coefficients of different parts of one type of 700 × 350 Hbeam steel were numerically simulated by a Fluent software under the condition that the nozzle position was fixed. The results indicated that as air pressure increased,the heat transfer coefficient increased,but no regular effect of flow rate and diameter of the nozzle on the heat transfer was found.On the basis of the above,the air-vapour injection parameters were optimized,and the temperature fields under several working conditions were analyzed. Finally,it was determined that the temperature field of the 700 × 350 H-beam steel was the most uniform under the condition that water flow L1,L2 and L3 were 0. 05 kg/s,0. 1 kg/s and 0 kg/s respectively,and the nozzle air pressure was 0. 3 MPa.更多还原