What causes damage to the ladle breathable brick?

In the process of using ladle air-permeable bricks in steel factories, the main reasons for the damage of air-permeable bricks are thermal stress, mechanical stress, mechanical abrasion, and chemical erosion.

透氣磚由透氣芯和透氣座磚兩部分組成。 當開啟底吹氣時，透氣芯的工作面將直接與高溫鋼水接觸。 隨著使用次數的增加，由於受到的冷熱迅速，對透氣磚芯部的侵蝕會更深，容易產生裂紋。

底部透氣磚的工作面與高溫鋼水直接接觸，非工作面的溫度相對較低。 透氣磚及附近耐火材料在鋼筋接合、澆注、熱修等回收過程中，因溫度變化而體積發生變化。 體積變化，由於溫度梯度的存在和變質層與原層之間熱膨脹係數的差異，使透氣磚工作面向非工作面的體積變化程度逐漸變化，這會導致透氣磚的剪切。 剪切力使透氣磚在橫向上產生裂紋，嚴重時，透氣磚會在橫向上斷裂。

During the tapping process, the molten steel will have a high-strength scouring of the bottom of the ladle, which will accelerate the erosion of the air-permeable brick. When the upper surface of the breathable brick is higher than the bottom of the bag, it will be sheared and washed by the flow of molten steel. The part higher than the bottom of the bag will generally be washed away after one use. In addition, after refining, if the valve is quickly closed, the reverse impact of molten steel will also accelerate the corrosion of the ventilating brick.

透氣磚芯的工作面長期與鋼渣和鋼水接觸。 鋼渣和鋼水含有氧化鐵、氧化亞鐵、氧化錳、氧化鎂、氧化矽等，而透氣磚的成分包括氧化鋁、氧化矽等，會發生反應生成低熔化物質（如FeO·Al2O3、2(MnO)·SiO2·Al2O3等）並被沖走。