20CrMnTi钢铸坯加热过程横向断裂原因分析

Cause Analysis of Transverse Fracture of 20CrMnTi Steel Billet During Heating

针对20CrMnTi钢入轧钢加热炉出现自然断裂的问题,对铸坯的横向断口进行分析,结果表明主要原因是铸坯的凹陷和浇铸时二冷区域回温。通过调整保护渣的理化指标及优化结晶器水量,减少二冷回温等改进措施,改善了铸坯的凹陷,连续20个浇次5.46万t铸坯在入轧钢加热炉过程未出现自然断裂。

Aiming at the problem of natural fracture of 20CrMnTi steel entering the rolling reheating furnace, the transverse fracture of slab was analyzed.The results show that the main reasons are the depression of the billet and the temperature return in the secondary cooling area during casting.By adjusting the physical and chemical indexes of protective slag and optimizing the water volume of crystallizer, improvement measures such as reducing secondary cooling return temperature, the depression of billet was improved, and 54 600 tons of billet was poured for 20 consecutive times without natural fracture in the process of entering the rolling reheating furnace.