X70管线钢洁净度控制研究

针对某钢厂中厚板卷厂采用铁水倒罐→铁水预处理→转炉冶炼→出钢脱氧合金化→LF精炼炉→RH真空炉→钙处理→连铸生产X70管线钢生产工艺,采取系统取样分析,对P、S等杂质元素,N、H、O等气体的脱除规律以及夹杂物的控制规律进行了研究。研究表明,成品成分可以稳定控制水平为:w(P])≤0.004 5%,w(S])≤0.001 00%,w(O])≤0.000 85%,w(N])≤0.003 00%,w(H])≤0.000 15%,夹杂物以小于10μm的CaO-CaS为主,且单位面积总夹杂物数量小于12个/mm~2,成品钢具有很高的洁净度水平。

Research on Cleanliness Control of X70 Pipeline Steel

The system analysis is carried out in accordance with molten iron change tanks→molten iron pretreatment→converter smelting→tapping dioxidation alloying→LF refining furnace→RH vacuum furnace→calcium treatment→continuous casting productive X70 pipeline steel production technology in a steel factory.Study on P,S etc.impurity elements,N,H,O etc.gas removing regulation,and inclusion control regulation is carried on.Reasearch results show that finished products components can be controlled in a stability level:w(P])≤0.004.5％,w(S])≤0.001 00％,w(O])≤ 0.000 85％,w(N])≤0.003 00％,w(H])≤0.000 15％,the inclusion is less than 10 μm CaO-CaS as the leader and the inclusion total number in unit area is less than 12/mm2,finished steel has very high cleanliness level.