Production method of high-purity nickel-niobium intermediate alloy

Abstract

The invention provides a production method of a high-purity nickel-niobium intermediate alloy. The nickel-niobium intermediate alloy produced by an aluminothermic reduction process is selected as a raw material, and the high-purity nickel-niobium intermediate alloy is produced by adopting a vacuum induction furnace. The method comprises the following specific steps: (1) charging: vacuumizing, and adding a nickel-niobium intermediate alloy produced by a thermal reduction process from a charging chamber; (2) melting period: sending power to heat until the furnace burden is completely melted; (3) refining: starting refining when the temperature reaches the refining temperature; (4) deslagging: adding a slag former for deslagging; and (5) pouring is conducted, specifically, alloy pouring is conducted when the temperature reaches the pouring temperature. The nickel-niobium intermediate alloy produced through the method is good in component consistency, low in inclusion content and low in content of oxygen / nitrogen and other harmful gas elements, and the problems that alloy components produced through an aluminothermic reduction technology are segregated, many inclusions exist, and the oxygen element is not uniform are solved.

Description

technical field [0001] The invention belongs to the field of vacuum metallurgy, in particular to a production method of a high-purity nickel-niobium master alloy. Background technique [0002] With the continuous development of aero-engine, gas turbine, petrochemical and other industries, the use of superalloys is increasing year by year. The requirements for superalloy raw materials are also increasing. Niobium is an important strengthening element of superalloys. When niobium is added to superalloys, it mainly enters the γ' phase to form Ni. 3 (Al, Ti, Nb) increases the number of γ' phases, increases the γ' opposite phase boundary energy, increases the particle size of the γ' phase, and increases the degree of order, thereby enhancing the precipitation strengthening effect of the γ' phase. [0003] Because pure niobium raw materials have problems such as high melting point (melting point is 2468 ℃), difficult purification, high price, and easy segregation during use, nic...

AI Technical Summary

Problems solved by technology

At present, most of the nickel-niobium master alloys are produced by the aluminothermic reduction process. For example, patent applications such as CN104141083A and CN103255330A use aluminum powder as the reducing agent to react with niobium pentoxide and nickel oxide, and the produced alloy has composition segregation, The problem of many inclusions and uneven oxygen elements

Due to the heredity of the material, the niobium-containing superalloy produced by using this raw material will bring more inclusions, thereby reducing the yield of superalloy parts, and at the same time, the composition segregation of niobium in the raw material will also make the smelted superalloy alloy There is a difference between the chemical composition and the design composition, which will lead to unstable performance of the alloy and reduce the structural stability and service life of the superalloy

The patent application with publication number CN104988341A uses pure nickel and high-purity niobium as raw materials to produce nickel-niobium alloy through vacuum induction furnace, but it has the problem of high raw material cost and it is difficult to expand the market scale

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