| Continuous casting holds very important status during steel making, and the high-temperature properties of continuous cast slab are very important for guiding its production process. The high-temperature physical and mechanical properties parameters are also very important during the slab continuous cast process despite improving solidification cooling system, judging cracks in casting slab and establishing parameters of dynamic soft reduction in continuous casting. Paper select steel Q345 and AH36 slab casting in Liuzhou Iron and Steel Company to test part of mechanical behavior and physical property of steel casting blank under high temperature; on the mathematical model of heat transfer and stress variety in slab continuous casting process, MSC.Marc Finite-Element software is adopted to simulate the temperature and stress field of continuous casting process, and the result of simulation is analyzed.The test and measurement on two steel grades temperature expansion and differential thermal analysis are made according to the actual situation. Through these test and analysis the two steels high temperature physical property of casting slab like temperature expansion, heat capacity, latent heat, solidus curve and liquid line etc are achieved. In different speed of heating, we obtained the heat capacity of casting slab in the heating process and cooling process.Mechanical property variations with the temperature changing from 600 degree centigrade to 1300 degree centigrade are gotten through the Tension test t on the Gleeble-1500D and the steel high temperature brittleness zone especial the third one are determined according to the reduction rate of the cross-section. The second brittle zone of AH36 is about between 725 degree centigrade and 850 degree centigrade. The second brittle zone of Q345 is about between 725 degree centigrade and 900 degree centigrade.The two-dimension transfer model of heat transfer in slab continuous casting is built based on the mind of setting slices on the slab along the casting direction by MSC.Marc. With the steel performance parameter and the accurate edge conditions, using MSC.Marc Finite-Element software to dispersion and solve the heat transfer partial differential equation to get the cross-section temperature field of casting slab. Based on the temperature field, the two-dimension thermal elastic tress model is built and simulated by MSC.Marc.The paper apply MSC.Marc calculating AH36 steel and Q345 steel heat transfer and stress during the casing progress in the actual slab caster. The calculating casting blank temperature and the solidified thickness almost correspond with the measure in the production site.Ccomparing the simulation results and production practices, the calculating casting blank temperature and the solidified thickness almost correspond with the measure in the production site. The heat transfer model and stress model disclosures that the biggest temperature gradient and the biggest stress appeared in the casting blank corner and surface layer of casting. So the cracks occur easily in these areas. In the end of solidification, the cracks occur easily in the center of casting slab. |
