基于梯形轨迹的高速结晶器热调宽技术

On-line Width Adjustment Technology of High Speed Mold Based on Trapezoidal Trajectory

调宽速度是结晶器热调宽技术的重要技术指标。较高的调宽速度可以减小过渡楔形坯的金属切割损耗,在降低浇铸损耗的同时提高铸机作业率。合理的速度轨迹可以保证调宽过程中结晶器窄边对铸坯壳的均匀支撑与传热,避免铸坯缺陷与漏钢风险,是结晶热调宽技术的关键。采用了简单实用的梯形速度轨迹,在锥度调整的同时改变结晶器宽度,可以取得较高的调宽速度。结合调宽运动规律及驱动机构原理推导了速度轨迹的构造函数及参数设定,并给出了最大调宽速度Vp的数学表达式。生产验证表明,调宽过程中运动轨迹平稳光滑,结晶器窄边对铸坯壳的支撑均匀稳定,铸坯的附加作用力较小。在浇铸速度Vc=1.5 m/min,最大枢转角ζmax=2.3°条件下,实测单侧最大调宽速度Vp=60mm/min,达国际先进水平。

The width adjustment speed is an important technical index of the on-line mold width adjustment technology.A high width adjusting speed can reduce the metal cutting loss of the transition wedge, reduce the casting loss and improve the operation rate of the caster. The reasonable velocity trajectory can guarantee the uniform support and heat transfer between the narrow edge of the mold and the slab shell, and avoid the risk of slab defects and breakout, which is the key of the on-line width adjustment technology of the mold. A simple and practical trapezoidal velocity trajectory was used, which changed both the taper and width of the mold at the same time. As a result, a high width adjustment speed could be obtained. The construction function of the velocity trajectory and the parameter setting were deduced by combining the law of width adjustment and the principle of driving mechanism, and the mathematical expression of the maximum adjusting speed Vp was given. The production verification shows that the trajectory of the width adjustment is continuous and smooth, and the support of the slab shell with the narrow side of the mold is stable, and the additional force to the slab is small. When the casting speed Vc is 1.5 m/min and the maximum pivot angle ζmax is 2.3°, the measured maximum speed of the mold single side Vp is 60 mm/min, which reaches the international advanced level.