Analysis Of Heat Transfer Of TWIP980 Steel In Continuous Casting Slab Mold

This paper is based on the Fe-Mn-Al-Si-C model of TWIP980 steel as the research object,this steel has high Mn content so that its thermal conductivity become poor and its columnar crystal become rich,and it has high C content so that its thermoplastic become poor.Therefore,this steel is easy to appear crack and other defects in the continuous casting.And surface crack defects generally began in the early solidification,the shell began to form in the meniscus.The heat transfer between shell and mold plate is complicated.The solidification of liquid steel produces air gap in this interface,then the liquid slag is added to the air gap area.Due to the large temperature difference between the copper plate and the shell,some of liquid slag which near the copper plate begin to solidify,and the others near the shell is also liquid,during which the interface heat exchange in dynamic changes among them.So the temperature distribution of this interface affect the heat transfer behavior and then affect the evenness of the shell thickness,which is the key to the whole process of solidification.With the cooling process,if the crack of initial shell occurs,it will develop into surface crack,so the initial solidification process becomes the restrictive part which restricts the surface quality of high manganese steel slab.In this paper,the mathematical model of heat transfer in continuous casting mold was established,which based on TWIP980 steel as the research object.This paper uses Pro CAST software to calculate the temperature field and the stress field of 1110×120 mm2 slab.The thermal behavior of solidifying shell and the influence of different technological parameters on the heat transfer behavior of shell are analyzed.Calculation results show that: in the casting speed 1.5 m/min,the pouring temperature of 1450 ?condition,compared with the narrow face,the width heat transfer is uneven,average temperature of the width is significantly higher than the narrow face.Temperature of the width is greatly influenced by the air gap and the heat flux distribution is not uniform.The overall heat flux of the wide surface is smaller than the narrow surface.The casting speed,pouring temperature and cooling intensity of mold all have different degrees of influence on the heat transfer behavior in the mold.Casting speed increased by 0.2 m/min,the slab average temperature increased by about 20 ~ 30 ?.Pouring temperature increased by 10 ?,the slab surface temperature increased by about 8 ~ 14 ?.Mold cooling water flow rate increased by 0.5 m/s,the slab surface temperature increased by about 5~8 ?.