Research On Temperature Field During Annealing Process Of Full Hydrogen Bell Furnace

In order to eliminate work-hardening and restore plasticity,cold-rolled strip steel needs to be annealed.Advanced annealing technology is the key to producing high-quality cold-rolled steel products.The full hydrogen bell furnace is widely used in the annealing of cold-rolled strip because of its lower investment cost,suitable for more types of materials,better deep-drawing performance and so on.Putting cold-rolled steel coils into the full hydrogen bell furnace,after heating,insulation,cooling,complete the annealing.The distribution and change of the temperature field of the steel coil during the annealing process determines its annealing quality.There are still some shortcomings in the study of the annealing technology in the bell furnace,especially in the study of the temperature field of the steel coil and the flow state of protective gas.Therefore,this paper focuses on the temperature field and the velocity distribution of protective gas in the annealing process of the full hydrogen bell furnace,and pays attention to the analysis of the distribution and changes of the temperature field of the steel coil during the annealing process,and provides theoretical foundation for the establishment and optimize of the annealing process in enterprise production.The main research contents include:(1)Based on engineering heat transfer,the radial heat conduction model of steel coil,the model of convection heat transfer,this paper establishes the mathematical model of the temperature field during the annealing process of the full hydrogen bell furnace,and analyzes the solution method of the mathematical model.And carries out the temperature field tracking experiment of the steel coil,compares and analyzes the error and the cause of the calculation result of the mathematical model and the measured data,to optimize the mathematical model.Finally,obtains a more accurate mathematical model whose calculation accuracy can meet the production requirements of the enterprise.(2)Based on Bernoulli's equation and flow loss equation,this paper establishes a mathematical model of the flow rate distribution of protective gas in full hydrogen bell furnace,and when the coil specifications,furnace loading conditions and specifications of full hydrogen bell furnace are different,applies CFD simulation technology simulate the flow velocity distribution of the shielding gas everywhere in the furnace.Comparing and analyzing the mathematical model and CFD simulation results,a more accurate mathematical model is obtained,and the calculation error is within the allowable range.(3)Combining the velocity distribution of protective gas and the mathematical model of temperature field,this paper accurately solves the distribution and changes of the temperature field at any position of the steel coil during the annealing process.Considers of the formulation principle of the annealing process,this paper analyzes the strategy of annealing process system optimization,and provides theoretical guidance for the formulation and optimize of annealing process.In addition,this paper develops an evaluation and optimization platform of the annealing process,which can be applied to the production site of the enterprise to help field personnel to evaluate and optimi ze the existing annealing process.