高压锅炉管用钢P12的洁净度分析

Analysis of Cleanliness of P12 High-pressure Boiler Steel

通过对EAF-LF-VD-MC工艺生产P12各工艺环节系统取样,采用多种分析方法分析夹杂物的形貌、尺寸、数量及组成,系统研究了P12生产过程中洁净度演变规律。研究结果表明,在精炼环节,钢中T[O]和显微夹杂分别下降51.2%、50.8%;VD处理后到锻材中,钢液增氮率为54.2%,钢液二次氧化较为显著;锻材中T[O]、显微夹杂和大型夹杂数量平均值分别为20×10-6、6.19个/mm2、0.35 mg/kg,达到了较高水平。

The cleanliness of P12 steel produced with EAF-LF-VD-MC process was studied systematically by sampling in various process stages in the production and with multiple analyzing techniques investigating the shape,size,quantity and component of inclusions.The results indicate that,in the refining process,T[O] and microinclusions in steel reduce 51.2 percents and 50.8 percents respectively.After VD treatment,average nitrogen increase rate of molten steel is 54.2 percents right to forging ingot and secondary oxidation of molten steel is rather noticeable.The average amount of oxygen,microinclusions and large inclusions are 20×10^-6,6.19 per squar6e millimeter and 0.35mg/kg respectively,reaching rather high levels.