Research And Application Of Quenching Controlling System Of Plate Roller Quenching Machine

Based on3800mm plate roller quenching machine project of Xinyu iron&Steel Co.Ltd, this paper aimed at development and application of roller quenching controlling system of carbon steel. Calculation models of plate temperature, water flow and prediction of microstructure and mechanical properties are studied in this paper. The quenching process controlling system is applied to produce XGCF62successfully. The main contents and results are as follows:(1) To meet the need of roller quenching technology of carbon steel, controlling system contains basic automation controlling system and process controlling system. Basic automation could be used to track plate location, regulate water flow and monitor the parameters. Process controlling system can perform the function of calculation of plate cooling temperature and water flow, prediction of microstructure and mechanical properties.(2) According to theneed of roller quenching technology, PID regulator is adopte to regulate water flow. First, make Ti and Td zero, through regulating Kp to watch the response speed and overshoot, then choose the best one. This regulation controlling system lays a good foundation for meeting the need of accuracy and speed of water flow.(3) The heat conduction equations were developed in roller quenching process of the steel plate. Based on the measurement data in the production and the actual roller quenching processing parameters, average heat transfer coefficient of high-pressure-slot section in the cooling process have been gained with inverse heat conduction method. The calculation results were significant for analyzing the temperature field in different roller speeds and controlling the cooling rate during quenching.(4) In need of the flow control in the cooling system of roller quenching machine, the analytical calculation model of spraying water flow was established in the part of high and low pressure. According to the flux and pressure values measured in the production field, the key correction factors of calculation model of spraying water flow were gained in the regression analysis. Compared with the measure value in practice, the result from the calculation model deviated less than10%, so the calculation model could be affirmed as a high accuracy one.(5) Based on steel chemical composition and parameters of quenching process, prediction of microsture and properties is carried out according to the classical model of Maynier, with the interpolation and weighing sum method. Taking vessel plate07MnNiMoVDR of30mm for example, the composition of microstructure and Vickers hardness in the thick direction could be calculated in order to serve the operation in practice.(6) Combined with development of quenching technology, process controlling system is applied to the productive produce. Matured and stable quenching technology is developed successfully.