高压气瓶钢34Mn2V 200mm×200mm轧坯角部拉裂缺陷的控制工艺

Control Process on Corner Crack of 200 mm×200 mm Hot Rolled Billet of Steel 34Mn2V for High Pressure Bottle

通过工艺对比分析了34Mn2V高压气瓶用钢中间包浇铸温度、结晶器液面波动、[Als]、中问包炉次和280 mm×380 mm连铸坯拉速波动对轧坯角部拉裂的影响。提出减小RH加Al量,按[Als]0.01%控制;RH后喂Ca-Si线;适当提高连铸钢液温度,控制中间包钢水温度1 520～1 530℃;控制浇铸过程塞棒吹氩量≤10 L/min;结晶器液位波动±3 mm等工艺措施。应用结果表明,轧坯角部拉裂缺陷率由原来的23.57%降至1.21%。

The effect of temperature of liquid steel in tundish during casting, liquid level fluctuation in mold, [ Als ], sequence heats of tundish and fluctuation of 280 mm × 380 mm bloom casting speed on rolled billet comer cracks of steel 34Mn2V for high pressure bottle was analyzed by processes comparison. The process measures have been adopted including decreasing adding A1 amount, controlling [ Als] 0.01%, feeding Ca-St wire after RH, suitably increasing liquid steel temperature during cast, controlling liquid steel temperature 1 520 - 1 530℃ in tundish and stopper argon blown rate ≤10 L/min during casting, and controlling mold liquid level fluctuation ± 3 mm. Application results showed that the hot rolled billet comer cracks rate decreased from original 23.57% to 1.21%.