Vacuum arc remelting method for inhibiting macrosegregation of high-temperature alloy with high content of Nb

Abstract

The invention discloses a vacuum arc remelting method for inhibiting the macrosegregation of high-temperature alloy with high content of Nb, comprising the following steps: subjecting the high-temperature alloy with high content of Nb to vacuum arc remelting, wherein in the normal remelting process, the melting pressure is controlled at 22-30V, the melting current is controlled at 5,000-7,000A, and the molten drip rate is controlled at 6-8 drops per second; and cooling by water and helium filling, wherein the pressure of the helium is controlled at 300-500Pa. The invention further discloses the high-temperature alloy with high content of Nb, which is obtained by melting by adopting the method. According to the characteristics of a vacuum arc furnace and the characteristic that the high-temperature alloy with high content of Nb is easy to be subjected to macrosegregation in the process remelting by using the vacuum arc furnace, the vacuum arc remelting process parameters can be formulated reasonably, the macro component segregation is prevented and inhibited effectively. The product obtained by melting has good quality, high production efficiency and significant economic benefit.

Description

technical field [0001] The invention belongs to the field of high-temperature alloy smelting in the metallurgical industry, and relates to an alloy quality control method in the vacuum arc remelting process of high-temperature alloys, and more specifically, relates to a vacuum arc remelting method for suppressing macro-segregation of high-temperature alloys with high Nb content . Background technique [0002] Metal Nb is a high-melting point metal with a melting point of 2468°C and a boiling point of 4742°C; adding Nb to superalloys can improve the welding performance of the alloy, and improve the high-temperature strength and oxidation resistance of the alloy. Therefore, there are many superalloys containing Nb, and the main chemical compositions of commonly used Nb-containing superalloys are shown in Table 1. It can be seen from Table 1 that in terms of weight percentage, the Nb content requirements in GH4169, GH2907 and GH2909 alloys are 4.8-5.5%, 4.3-5.2% and 4.3-5.2%, ...

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Problems solved by technology

Among them, balanced solidification is difficult to achieve in actual production; grain refinement requires good thermoplasticity of the material, and superalloys with high Nb content have high alloy strength and poor hot-working plasticity, so it is difficult to achieve; homogenization annealing Treatment can only improve microscopic segregation. Whenever macroscopic segregation is found, the degree of segregation is often already serious, so the effect of homogenizing annealing on improving macroscopic segregation is not obvious.

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