Method for preparing dispersion strengthening ferritic alloy steel powder of nanometer yttrium oxide particles

Abstract

The invention discloses a method for preparing dispersion strengthening ferritic alloy steel powder of nanometer yttrium oxide particles. The method includes adding ethylene diamine tetraacetic acid and chromic nitrate into water, stirring the mixture at a temperature in a range from 50 DEG C to 60 DEG C for at least 12 hours, and obtaining a mixed liquid; adding citric acid, ferric nitrate, ammonium paratungstate, yttrium nitrate and tetrabutyl titanate into the mixed liquid, mixing the mixture at a temperature in a range in a range from 60 DEG C to 70 DEG C for at least 3 hours, and obtaining colloidal sol; adding polyethylene glycol into the colloidal sol, stirring the mixture at a temperature in a range in a range from 70 DEG C to 80 DEG C to form gel; and finally drying the gel at a temperature in a range from 100 DEG C to 120 DEG C for at least 12 hours and roasting the gel at a temperature in a range from 300 DEG C to 600 DEG C for 4 to 5 hours in sequence to obtain precursor oxide powder, placing the gel in a reducing atmosphere, roasting the gel at a temperature in a range from 1100 DEG C to 1300 DEG C for at least 3 hours to obtain object products which comprise, by weight, 12% to 14% of chromium, 2% to 3% of tungsten, 0.2% to 0.5% of titanium, 0.1% to 1% of yttrium oxide, and the balance iron. Yttrium oxide is evenly dispersed and distributed on matrixes composed of chromium, tungsten, titanium and iron, and the products can be used in fast breeder reactors and fusion reactors.

Description

technical field [0001] The invention relates to a preparation method of alloy steel powder, in particular to a preparation method of nano-yttrium oxide particle dispersion strengthened ferrite alloy steel powder. Background technique [0002] Oxide dispersion strengthened (ODS) alloy steel with high service temperature, high yield strength, good high temperature creep performance, excellent resistance to radiation hardening, swelling and brittleness has become a very promising structural material for fast breeding reactors and fusion reactors candidate materials. In ODS alloy steel, based on oxide dispersed phase such as yttrium oxide (Y 2 o 3 ) particle size and particle distribution are the key factors to determine the material properties, therefore, people have made some attempts and efforts in order to obtain higher quality ODS alloy steel, as in the 27th issue of "Powder Metallurgy Technology" published in October 2009 Volume No. 5 "Preparation Y 2 o 3 In the artic...

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Problems solved by technology

However, although this preparation method can obtain Y 2 o 3 The particle distribution is uniform, the particles with a diameter of less than 50nm account for about 50% of the total, and the average roundness of the particles is 1.25. The basically circular powder has some unsatisfactory features. First, the precursor powder——Fe- Cr-Ti-W-V alloy powder can only be obtained through the process of smelting pre-master alloy ingot in vacuum induction furnace, forging into round bar, peeling and grinding, and nitrogen atomization powder making, so it is energy-consuming, time-consuming and laborious; secondly, in Mix the alloy powder in Y(NO 3 ) 3 When the mixture is formed in the sol to prepare the ODS ferrite alloy, because the alloy powder cannot be effectively complexed with the organic complexing agent and cannot form a uniform colloid, not only the Y in the final product 2 o 3 The size is not uniform, so that the dispersion of the particle size is too large, but also because of the Y 2 o 3 The size of the particles is mainly dispersed around 50nm and the particle size is too large, which affects the mechanical properties of the final product

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