Anti-wear Mechanism Of Metal-nitride Bonded Corundum Sliding Plate

The properties, structures and anti-wear mechanisms of the metal-nitrides bonded corundum plate brick (TGO) and the contrastive plate brick (SJO) were studied in this paper. The results showed that TGO exhibited some features characterized by cermet. The most outstanding characteristic of TGO and SJO is their strengths at high temperature which are 1～2 times higher than normal plate bricks. In the author's opinion,this was caused by the"plastic phase structure"formed at high temperature. The oxidizing character of TGO and SJO was one of the most important characters which would influence their performances. Weight increases were observed during the oxidizing process of TGO and SJO and led to a higher density and penetration resistance. The weight increase of TGO was more than that of SJO. The protective solid layer between steel liquid and melted aluminium formed in the oxidizing process of the melted aluminum prevented it from being rushed away. Hence the result that the aluminium will act not only as an additive but also as a main raw material in the refractory mix. The wear factors of TGO were crack, regional spalling of stroke path and the release of melted aluminum., etc and among them the release of melted aluminium was the main factor. The AlN in the mix restrained the melted aluminium from releasing .To reduce this releasing, the amount of aluminium in the mix should be less than 15% and an even distribution should also be achieved. TGO had a lower thermal shock resistance due to higher thermal expansion coefficient and extended cracks by caused by the alternant reunion and cooling of aluminum. And its good corrosion resistance attributed to the excellent penetration resistance caused by oxidizing action of the mix. The corrosion was caused by the dissolving of the corundum in the slag during which lower melting AL2O3-SiO2-CaO and MgO·Al2O3 have formed. Although SiC itself exhibits good resistance to slag attack, it will act only to a very limited degree due to frequent changes of temperature and pressure of oxygen during steel casting, some negative effects will maybe occur under these circumstances.