Study On Optimization Design And Numerical Simulation Of Small Steel Ingot

Compared with continuous casting, ingot casting had incomparable advantages in solving special circumstances, for instance, the small batch, high alloy, large single heavy, et al. Therefore ingot casting still existed widely in the field of special steel,although there were some problems such as the more internal defects, low yield and the mould loss, et al. In the enterprises of special steel making, it was an eternal target to increase the yield and prolong the service life of the mould by optimizing the design of ingot and mould, such as the cross-section shape, mould wall thickness,pre-arch shape, corner radius and other parameters. Over the years, however, the development of continuous casting made the research of ingot casting be far from enough. The technical personnel engaged in research on ingot casting mostly rely on the existing experience, lacking the complete theory support.The wide application of computer numerical simulation technology, provided the possibility for the optimization design of ingot casting industry. The use of numerical simulation method, not only saved the time of modification and validation for the designers, also provided the reference for the parameters setting in production process.This paper combined with the demand of practical production, used the Pro-Engineer software to establish the three-dimensional model of ingot and mould, which contained different cross-section shapes, different ingot mould wall thickness,pre-arch shapes and different corner radius, respectively. And by ProCast software,this study simulated the different design parameters of ingot and mould temperature and stress fields in the solidification process, respectively. Through the analysis of simulation results, we got the optimization of design parameters.The results show that, the total solidification time of 3t ingot with rectangular cross-section instead of square cross-section, is shorted by 1.98 h to 1.50 h, reduced24.24%; By comprehensive consideration of ingot mould heat stress and mold shape variables, the reasonable value range of the wall thickness is set between 120 mm to140 mm; In order to ensure the stability of rolling, the height of the trapezoid pre-arch is generally set between 15 mm to 40 mm. When the range of corner radius changes between 0 to 60 degrees, with increasing the angle of corner radius, the stress concentration of the ingot mould corner gradually reduces. For square and rectangular ingot, the radius generally takes one-tenth of the average section length. The results of numerical simulation analysis were basically consistent with the test result, which verified the correctness of the consequences of numerical simulation. In actual production, the ingot by optimized design met the B ultrasonic testing after rolling,the qualified internal quality, and the average yield improves from 78% to 83.51%.