【摘要】 文中提出了一种适用于电渣重熔的还原稀土氧化物加稀土的新工艺。从热力学分析了用铝、钙、硅、钛及铁铬铝中的铝还原稀土氧化物成稀土金属进入合金的可能性。根据活度、熔体性质及正交设计试验确定了新的稀土渣系的合理组成及相应的工艺条件。实验表明,用稀土渣进行电渣重熔能使OCr25A15中含稀土量达0.02％,与Al₂O₃-CaF₂系比较它具有更强的去氧、氮、硫、磷、氢及夹杂的能力。再加稀土改变了夹杂物的类型和形貌。使OCr25A15合金在1350℃寿命达62小时以上,常温韧性及寿命试验后的伸长率亦得到了改善。更多还原

【Abstract】 A new ESR technique with adding rare-earth metals to alloys by reduction of rare-earth oxides is presented in this paper. The possibility of reduction of rare-earth oxides to metals by aluminum in Fe-Cr-Al alloys as well as by aluminum, calcium, silicon and titanium has been studied from the view point of thermodynamics. According to the activities, the properties of the melts and -esults of the normal distribution tests, a new electro-slag system which has a reasonable composition of rare-earth oxides and a corresponding technology have been established. Experiments have proved that remelting of the rare-earth slag would make it possible to contain 0.02% rare-earth metals in OCr₂₅ Al₅ alloy. Compared to the Al₂O₃-CaF, system, this slag is more effective to eliminate impurities, such as oxygen, nitrogen, hydrogen, phosphorus and sulfur, and to floot out the non-metallic inclusions. In addition, the types and morphologies of the inclusions have been changed by rare-earth metals. It has been found that the service life of OCr₂₅Al₅ alloy produced in this way is more than 62 hours at 1350℃. The toughness at room temperature and the elongation after life test have been improved also.更多还原