高等级管线钢板的开发及应用

Development and Application of Higher Grade Pipeline Steel Plate

针对高等级管线钢的性能特点,通过成分设计,利用兴澄特钢4300mm宽厚板分厂的双机架大轧制力轧机及直接淬火(DQ)+快速冷却(ACC)冷却系统,开发并批量生产了X70M系列高等级管线用钢,同时系统研究了钢水纯净度和控轧控冷工艺对DWTT性能的影响。结果表明,合理的成分、连铸及控轧控冷工艺设计有助于钢板获得细小的针状铁素体(AF)+准多边形铁素体(QF)组织,并在保证高强度情况下取得优良的低温冲击韧性和低温落锤性能。

According to the properties features of higher grade pipeline steel,X70M series higher grade pipeline steel has been developed and produced in batch by chemical composition design,high rolling force twin stand mills and cooling system of DQ+ACC in 4 300 mm Wide and Heavy Plate Rolling Plant of Xingcheng Special Steel Works,the effects of steel cleanliness and controlled rolling and controlled cooling process on DWTT properties are systematically studied.The results show that rational design of chemical composition,continuous casting process and controlled rolling and controlled cooling process facilitates the formation of refined acicular ferrite and quasi-polygonal ferrite in steel plate,ensures excellent low temperature impact toughness and DWTT properties at higher strength.