Preparation process for nickel-based high-tungsten polycrystalline high-temperature alloy

Abstract

The invention relates to a preparation process for a nickel-based high-tungsten polycrystalline high-temperature alloy. The preparation process comprises the following steps that alloy smelting is carried out, specifically, the following components of, in percentage by mass, 15%-18% of Cr, 15%-20% of Co, 0.5%-1.5% of Ti, 3.5%-4.5% of Al, 7.0%-8.5% of W, less than or equal to 0.5% of Si, less thanor equal to 0.5% of Mn, 0.5%-1.5% of Nb, 0.03%-0.08% of C, and the balance Ni are smelted under the vacuum degree of 0.3-0.5 Pa and the protection of argon, and then refining is carried out by adopting an electroslag remelting process to obtain a ingot casting; then hammer cogging is carried out; high-temperature rolling is carried out; and final heat treatment is carried out. According to the preparation process, the alloy is completely recrystallized after being subjected to heat treatment, the grain size of the alloy is 30-50 mm, Ni3Al phases are dispersedly distributed in a crystal, the volume fraction of the Ni3Al phases is not lower than 35%, and the yield strength of the alloy is not lower than 700 MPa under the condition of 850 DEG C.

Description

technical field [0001] The invention belongs to the field of high-temperature alloy materials, and in particular relates to a preparation process of a nickel-based high-tungsten polycrystalline high-temperature alloy. Background technique [0002] As my country's electricity demand continues to increase, energy shortages and environmental pollution problems have become increasingly prominent, and the need to develop high-efficiency, energy-saving, and environmentally friendly power generation methods has become increasingly urgent. Thermal power generation has been the most important power generation technology in my country for a long time, and improving the steam parameters of the unit is considered to be the most effective way to solve the above problems. A lot of practice in the past has shown that the service performance of key component materials is the most important factor restricting the improvement of steam parameters of boiler units. Service performance puts forw...

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Problems solved by technology

However, the addition of Mo element will have an adverse effect on the corrosion resistance of the alloy and significantly endanger the stability of the alloy structure.

The solid solution strengthening effect of W element is more significant than that of Mo element, but its addition will significantly reduce the hot workability of the alloy, thereby increasing the difficulty of alloy preparation and forming

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