轧制工艺对高铌X80管线钢组织性能的影响

通过热模拟实验,研究了加热温度、变形温度、变形量、冷却速率和卷取温度对高Nb含量管线钢钢板组织性能的影响,并确定了工业生产方案。工业试制结果表明:在1 170~1 200℃进行加热保温,粗轧温度控制在1 020℃以上,变形量控制在30%以上,精轧入口温度不大于950℃,终轧温度控制在(800±20)℃,冷却速率控制在10~30℃/s,卷取温度控制在500~530℃,生产的高Nb含量X80管线钢钢板组织为均匀的针状铁素体,力学性能优良,-20、-40℃低温冲击功均达到300 J以上,-15℃落锤撕裂试样的剪切面积达到97%以上。

Effects of rolling processes on microstructures and properties of X80 grade pipeline steel with high Nb content

Through the thermal simulation experiment, the influences of heating and deformation temperature, reduction, cooling rate and coiling temperature on the microstructure and properties of high Nb content X80 pipe line steel plate were studies, and the industrial production schemes were designed. Industrial trial results show that the heating temperature is controlled at 1 170?1 200 ℃, the roughing rolling temperature is controlled at 1 020 ℃, the amount of deformation is controlled above 30%, the finishing start rolling temperature is controlled above 950 ℃, the final rolling temperature is controlled within (800 ±20) ℃, the cooling rate is controlled within 10?30 ℃ /s and the coiling temperature is controlled at 500?530 ℃. Based on it, the microstructure of high Nb content X80 pipeline steel plate is the needle like iron uniform ferrite, and the excellent mechanical properties of plate are obtained. Meanwhile, the impact energy values at ?20、?40℃ are reached above 300 J, and shear area at ?15 ℃ of DWTT specimen is achieved above 97%.