Nickel-base high-temperature alloy with low density and high melting point and preparation process thereof

Abstract

The invention relates to high-temperature alloy technology, and in particular provides an isometrical cast nickel-base high-temperature alloy with low density, high incipient melting temperature and good casting property and a preparation process thereof, which can be used for floating tile materials of a combustion chamber. The alloy comprises the following compositions by mass percentage: 0.03 to 0.06 percent of C, 5 to 12 percent of Cr, 5.5 to 6.5 percent of Al, 3 to 8 percent of Co, 3 to 7 percent of W, 2 to 4 percent of Mo, 1.6 to 3.2 percent of Nb, 0.01 to 0.03 percent of B, 0.008 to 0.025 percent of Y and the balance of Ni. A vacuum induction furnace is adopted to smelt a master alloy, and a smelting crucible is a CaO crucible or a MgO crucible; and the operation process comprises the following steps: putting alloying elements such as carbon, chromium, cobalt, tungsten, molybdenum and niobium in proportion and a nickel plate into the crucible; melting the alloy when the vacuum degree reaches between 50 and 0.1 Pa; and after completion of the melting, refining for 30 to 300 seconds at a temperature of between 1,550 and 1,600 DEG C, cutting off electricity, forming a film, breaking the film to add Al and Al-Y and Ni-B interalloy for uniform stirring, and casting a master alloy pig at a temperature of between 1,450 and 1,500 DEG C. The invention solves the problems of low incipient melting temperature, poor plasticity and inoxidability and the like of the nickel-base high-temperature alloy.

Description

technical field [0001] The invention relates to superalloy technology, and in particular provides an equiaxed casting nickel-based superalloy with low density, high initial melting temperature and excellent casting performance and its preparation process, which can be used as a floating tile material for a combustion chamber. Background technique [0002] Superalloys refer to a class of metal materials based on iron, nickel, and cobalt that can work for a long time at high temperatures above 600°C and under certain stresses. For half a century, the temperature before the turbine of the aero-engine has increased from 730°C in the 1940s to 1677°C. The increase in service temperature puts forward more and more stringent requirements on the materials of aero-engines. Nickel-based superalloys are by far the most superior performance and the most widely used aero-engine materials. At present, the upper limit temperature of the alloy's service temperature has reached about 1200 °...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a high initial melting temperature, good high temperature strength, low specific gravity and low cost, good castability and excellent comprehensive performance equiaxed casting nickel-based superalloy and its preparation process, to solve the problem of nickel-based superalloy primary Low melting temperature, and poor plasticity and oxidation resistance

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