管线钢精炼深脱硫工艺研究

管线钢要求有高强度、高韧性,特别是低温冲击韧性和止裂韧性、抗腐蚀介质氢致裂纹、良好的焊接性能等,硫是影响管线钢抗氢致裂纹和抗硫应力裂纹的主要元素。根据精炼脱硫机理,结合济钢生产实际,以LF-VD双联法生产超低硫管线钢工艺为对象,分析了VD真空状态下脱硫的技术条件及可行性。采用该脱硫工艺生产X70管线钢,平均脱硫率提高到80%左右,实现了深脱硫。同时,减轻了LF炉脱硫的压力和处理时间,提高了钢水的纯净度。

RESEARCH OF DEEP DESULFURIZATION PROCESS IN REFINING OF PIPE LINE STEEL

It is asked for pipe line steel the high-strength,high-toughness,especially low-temperature impact toughness and crack arrest toughness,resistance to corrosion media hydrogen assisted cracking,excellent welding property and etc.Sulphur is the main element to affect the resistance of pipe line steel to hydrogen assisted cracking and sulphur-stress cracks.Based on refining desulphurization mechanism,combined with production practice of Ji Steel,taking process to produce ultro-low-sulphur pipe line steel with LF-VD duplex method as example,it is analyzed the technical condition and feasibility of desulphurization under VD vacuum.With the above process to produce X70 pipe line steel,the average desulphurization ratio raised up to about 80%,the deep desulphurization realized.At the same time the desulphurization burden for LF furnace reduced and treating time shortened,the purity of molten steel raised.