Research And Application Of Rolling Quenching Technology For Heavy Plate

Large cross-section,large single heavy-thick steel plate is one of the basic raw materials urgently needed in our country,quenching is to enhance the overall toughness of the key processes.In view of the problems of low cooling speed,poor uniformity of thickness cooling and low production efficiency of the quenched heart of the conventional thick steel plate,the convection heat transfer mechanism of the arrayed array jet was studied around the roll quenching of the steel plate.The jet flow Field on the heat transfer surface heat transfer form and heat distribution area of the law,proposed a three-dimensional non-steady-state temperature analysis method for the quenching of the ultra-thick steel plate,established to improve the heat transfer efficiency of the steel surface and the heart of the cooling rate of heat transfer,Thermal conductivity and multi-field coupled mathematical model.The model was modified to develop a special steel plate roll quenching strategy aimed at improving the cooling rate of the core and the uniformity of thickness cooling.Relevant research results are applied to the first set of special thick steel plate roller quenching equipment technology,developed a thick plate of high strength,high uniformity quenching technology.(1)According to the experiment of two kinds of quenching methods of immersion type and continuous type and the effect of different intermittent tactics on the temperature drop of super-thick steel plate,the paper analyzes the superficial steel plate above 120 mm,Thermal process,analysis of intermittent strategy(water cooling,air cooling interval)on the thickness of the heart rate of the law of the table,compared to come to a better quenching procedures.(2)Based on the three-dimensional unsteady heat transfer equation,the finite element method and the differential solution method were used to establish the model of thermal conductivity of steel plate,the calculation model of surface convection heat transfer coefficient and the prediction model of depth of hardened layer.To meet the high-precision heat treatment process control needs.(3)Based on quenching and cooling model of extra-thick steel plate,the temperature control and shape control of the extra-heavy plate quenching process have been realized through the calculation of the procedure distribution,the calculation of the plate shape control parameters and the automatic quenching control parameters,which meet the industrial production and use requirements.(4)In order to improve the accuracy of the three-dimensional heat conduction equation,this paper studies the calculation formula of thermophysical parameter fitting obtained by measuring the specific heat,thermal conductivity and density of test steel with temperature.The related research is instructive for promoting R&D of thick steel plate roll quenching process,developing new type of special plate hardening equipment and industrialized application.