中频炉精炼短流程炼钢镁碳砖问题分析 Analysis problem of Magnesium Carbon Brick in Short Process of induction Furnace Refining

May 11, 2020

中频炉炼钢过程中,由于原材料限制,在冶炼过程中需要加入部分氧化铁皮降低钢水的碳含量,再加入大

量氧化铁皮去稀释钢水中的碳含量过程中,但由于,氧化铁皮中含有大量 FEO, FeO 在高温下很

容易与镁碳砖中石墨发生氧化反应,并且产生亮白色铁珠,形成脱碳层,其次镁碳砖中的方镁石亦会同炉中的 FeO 反应生成低熔点产物。

在钢包反复加热和冷却的过程中,由于形成的镁铁复合低熔点产物和镁铁矿之间的热膨胀率

不一致,使耐火材料表面的氧化镁发生破碎,进而导致砖体的溶解。FeO 加速了镁碳砖表面

碳的氧化,其次是 FeO 会与 MgO 反应,使镁碳砖工作面结构疏松,就在这两点的共同作用

下使镁碳砖加快侵蚀。其次脱碳层形成的疏松结构在热膨胀与熔渣的冲刷作用下产生更大的

裂纹与孔隙,使炉渣方便渗透,并与 MgO 形成低熔点相,同时在熔池剧烈的机械搅动和钢

渣猛烈冲刷的作用下镁碳砖的表面层结构组织发生改变,最终由外向内逐渐损毁,致使镁碳

砖遭到严重破坏。在温度超过一定值后,砖体组织会受到破坏从而急剧蚀损。

 

In the process of induction furnace steelmaking, due to the limitation of raw materials, it will need to add some iron oxide(iron scrap or iron scale ) to reduce the carbon content of molten steel and then add the iron oxide (iron scrap or iron scale) is used to dilute the carbon content in molten steel, but because it contains a lot of FEO,FeO at high temperatures

Oxidation reaction with graphite in magnesia-carbon brick is easy, and bright white iron beads are produced to form decarburization layer.

In the process of repeated heating and cooling of ladle, the thermal expansion rate between Mg-Fe composite low melting point product and Mg-Fe is formed

inconsistent, so that the refractory surface of magnesium oxide broken, and then lead to the dissolution of brick body. FeO accelerates the surface of magnesia-carbon brick

The oxidation of carbon, followed by the reaction of FeO with MgO, makes the structure of magnesia-carbon brick working face loose.

Under the magnesia carbon brick accelerated erosion. Secondly, the loose structure formed by decarburization layer has a larger effect on thermal expansion and slag scouring

Cracks and pores make the slag easy to penetrate and form a low melting point phase with the MgO, while vigorous mechanical agitation and steel in the molten pool

The structure of the surface layer of Mg-C brick is changed under the action of slag scouring, which is gradually destroyed from outside to inside, resulting in Mg-C bricks were badly damaged. After the temperature exceeds a certain value, the structure of the brick body will be destroyed, which will be eroded sharply.