Gas atomization method for preparing oxygen supersaturated iron-based alloy powder

Abstract

The invention relates to a gas atomization method for preparing oxygen supersaturated iron-based alloy powder. The iron-based alloy powder is prepared by the gas atomization method, an alloy melt is subjected to high-speed gas atomization and quick cooling by comprehensively controlling the oxygen content and atomization pressure of an atomization medium and the superheat degree of the melt, oxygen is introduced in the atomization process, the oxygen content of atomized powder is controlled by controlling the oxygen content of atomization gas, high-concentration solid solution oxygen and high-concentration vacancies are obtained according to the quick solidification characteristic of gas atomization, the oxygen is prevented from reacting with alloy elements so as not to form stable oxide, and a high-purity high-quality powder raw material is provided for preparing a nano cluster strengthened alloy. The oxygen content of the iron-based alloy powder prepared by the gas atomization method is controllable in the range of less than or equal to 1.00 percent, the oxide is not generated, and the method is particularly suitable for preparing the iron-based alloy powder containing high-activity alloy elements such as rare earth, Ti, Cr and the like, and is simple, high in production efficiency, low in cost and suitable for large-scale production.

Description

technical field [0001] The invention relates to a method for preparing gas-atomized iron-based alloy powder, in particular to a gas-atomized method for preparing oxygen-supersaturated iron-based alloy powder; it belongs to the technical field of metal powder material preparation. Background technique [0002] Oxide dispersion strengthened (ODS) alloy is an alloy (called ODS alloy) that uses ultrafine oxides with high thermal and chemical stability to strengthen the alloy matrix. It has both dispersion strengthening and precipitation strengthening. With multiple strengthening mechanisms, it has excellent high-temperature mechanical properties and oxidation resistance, good heat transfer and radiation swelling resistance, and is widely used in aero-engines, gas turbines, nuclear reactors, automobiles, glass and other fields. At present, ODS alloys are mainly prepared by mechanical alloying (MA) method to uniformly disperse oxide particles into the alloy powder matrix, and then...

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Problems solved by technology

[0004] (2) It is difficult to control the oxygen content: the oxygen content is controlled by the oxygen content of the raw material powder and the MA process

Since MA powder making needs to control the oxygen content of the raw material powder and the oxygen increase in the MA process at the same time, it is difficult to control the oxygen content of the powder in the MA process;

[0005] (3) Long process cycle: To obtain alloy powders that are fully alloyed and have high thermal and chemical stability and uniformly dispersed hard oxides, it takes a long time for high-energy ball milling, long process cycle, low output, and low production efficiency. Large-scale industrial preparation brings difficulties;

[0006] (4) Poor repeatability: the size and dispersion of oxides are limited by the ball milling process and the original size of oxide raw materials, and the repeatability is poor, resulting in unstable alloy quality

Centrifugal atomization method is to use centrifugal force to break metal melt, and throw it out as atomized liquid droplets and solidify it into powder particles. The cost of the bar is high, the prepared powder is coarse, the cost is high, the production efficiency is low, the energy consumption is high, and the oxygen content cannot be adjusted by atomization

[0008] There is no relevant research report on the gas atomization preparation method of oxygen supersaturated iron-based alloy powder at home and abroad.

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