Simulation Of The Slab Thermal Stress Research And Application In Furnace Control System On Shougang 2250

The slab heating quality has a crucial effecton the subsequent rolling process. The 4 heating furnaces of Jing tang hot rolling 2250 production line arerely on manual operation, so the slab heating quality has large fluctuations.At the same time, this operation also causes high energy-consumption and high scaling loss.After reheating, some slabs appear camber which hasadverse effects to the stability of the rolling.It may cause serious HRC quality problems. The thinner rolling specifications is, the more sensitive to the camberissues.The main reason of the camber is that the temperature gradient in the slab width direction cause internal thermal stress. The relief of thermal stress causes the slab appear camber.Based on this quality problem, this paper carries out the simulation of temperature field and stress field of the slabreheating furnace.Under the condition of setting, this paperanalysis the law of the slab shape changing after heating.Combining with the combustion control system, we set the temperature system and control on the slab heating quality.First of all, the heat transfer model in furnace and the stress field model are established. The software of Abaqus finite element simulation method is used.Then the boundary conditions and thermal physical property parameters are selected.The process of slab reheating furnace temperature and slab tapping temperature are tested by Black box test and compared with simulation results..It is show that measured results and simulation results are in good agreement which verifies the accuracy of this model. The temperature field and the changes in thermal stress of the slab heating process is calculated by the finite element software, andthe source of slab camber is found to be the unreasonable heating system.Finally, the calculated results are appliedon the heating furnace combustion control system,and it improvesthe slab heating quality.According to the temperature of the system determined by the model, the reasonable air-fuel ratio is determined. The combustion of fossil fuels and the process of furnace temperatureare also controlled.Through the furnacetechnical improvement,the heatingquality of slabis better.Also, it brings economic benefits. The furnace oxide scale is significantly reduced. Slab oxidation loss rate is 1.41% in early 2011, which reduced to 1.01% in June 2012.The production of hot rolling 2250 line is about4.05 million tons in 2011,therefore the economic benefits more than ten million yuan to the company.