复合吹炼喷嘴套砖蚀损的研究

EROSION OF PROTECTIVE BRICK AROUND NOZZLE IN COMBINED BLOWN CONVERTER PROCESS

结合首钢转炉复吹工艺,采用热模拟实验研究了复吹 CO_2条件下金属喷嘴不同材质套砖的蚀损机理。发现当使用镁白云石套砖时,由于发生[Fe]-CO_2反应,在其工作面由外向内形成 MF、(Mg,Fe)O 及其 C_2F 富集带而引起材料变质,尤其液态 C_2F 的形成,大大降低了套砖的高温强度。镁碳质套砖的蚀损则是因为工作面上形成(Mg,Fe)O 及其部分石墨被氧化,造成材料高温强度下降及抗氧化性减弱。但镁碳质套砖因 CaO 含量低,避免了 C_2F 的形成,使得其抗侵蚀能力优于镁白云石套砖。

Based on the operation of combined blown converter with CO_2 at Shoudu Iron and Steel Co.the erosion mechanism of different protective brick around metallic nozzle has been studied bymeans of hot simulation method.It is found that in case of magnesitic dolomite brick there isa zone rich in MF,(Mg.Fe)O and C_2F formed on working surface of the brick and spread to theinterior because of[Fe]-CO_2 reaction,wnich seriously deteriorates the brick.Especially,the li-quid C_2F largely reduces the high temperature strength of the brick;the erosion of magnesite-carbon brick is cased by formation of(Mg.Fe)O on the working surface and oxidation of some gra-phite of the brick,thus both the high-temperature strength and oxidation resistance of the refrac-tory brick are reduced.Due to low content of CaO in magnesitc-carbon brick,the formation ofC_2F is avoided.That is the reason why the magnesite-carbon refractories possess better erosion-resistance than magnesite dolomite.