自熔合金熔炼增硅作用分析及控制

ANALYSIS AND CONTROL OF RESILICONIZING IN MELTING PROCESS OF SELF-FLUXING NICKEL BASE ALLOYS

在酸性炉衬中熔炼镍基自熔合金时常出现增硅问题,严重影响产品质量。增硅的原因一是原料中含有少量的杂质硅,随原料进入合金;二是酸性炉衬中的SiO_2被合金中的某些元素还原出来进入合金。后者是造成合金增硅的主要原因。本文探讨了增硅反应的条件,并以此为据提出了改进方法。采用先加硅的熔炼方法,并严格控制熔炼功率,可有效地控制镍基自熔性合金在熔炼过程中的增硅量。

Resiliconizing problem is usually confronted in the melting process of self- fluxing nickel base alloys in furnace with acid lining, which severely affects the product's quality. The resiliconizing is caused by two facts: (1) diffusion of impure silicon from raw materials into the alloys; (2) reduction of silicon oxide in the acid lining into silicon by some alloy elements and melting into the alloys during the melting process. The latter is proved the major cause of resiliconizing phenomenon. The resiliconizing prerequisite is discussed and the method to control it is also proposed in this paper. An effective controlling of resiliconizing extent in the melting process of nickel base self-fluxing alloys can be a-chieved by the technique of adding silicon at first and strict controlling of melting power.