Oxide dispersion-strengthened iron-based alloy powder and characterization method thereof

Patent metadata

Field	Value
Publication number	US-11584979-B2
Application number	US-201817263559-A
Country	US
Kind code	B2
Filing date	Aug 30, 2018
Priority date	Jul 27, 2018
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

An oxide dispersion-strengthened (ODS) iron-based alloy powder and a characterization method thereof are provided. The alloy powder comprises a matrix and strengthening phases. The strengthening phases include at least two types of strengthening phase particles with different sizes, wherein a volume of the particles with a particle size of less than or equal to 50 nm accounts for 85-95% of a total volume of all the strengthening phase particles. The matrix is a Fe—Cr—W—Ti alloy. The characterization method of the ODS iron-based alloy powder comprises separating the strengthening phases from the powder matrix through electrolysis, and analyzing and characterizing the strengthening phases using an electron microscope.

First claim

What is claimed is:

1. A method for preparing a ODS iron-based alloy powder, comprising:
Step 1: weighing a pre-alloyed iron-based powder and a rare earth oxide powder containing Y 2 O 3 according to a mass ratio of the pre-alloyed iron-based powder to the rare earth oxide powder containing Y 2 O 3 =97-99.5:3-0.5,
taking milling balls according to a ratio of a total mass of powder materials to a mass of the milling balls=1:10-20, and
filling the pre-alloyed iron-based powder, the rare earth oxide powder containing Y 2 O 3 and the milling balls into a milling can, and closing the milling can,
wherein the milling balls have diameters of 18-22 mm, 14-16 mm, 9-11 mm, 7-8.5 mm, 4.5-5.5 mm and 2.5-3.5 mm and are matched according to a mass ratio of 1-2:1-2:1-2:1-2:1-2:1-2;
Step 2: vacuuming the milling can to create a vacuum environment within the milling can, and then filling with an inert gas to create an inert gas atmosphere in the milling can;
Step 3: installing the vacuumed and filled milling can resulting from step 2 to a planetary ball milling machine, and mechanical milling, wherein parameters of the mechanical milling include a milling time of 40-120 hrs, and a milling rotating speed of 300-380 r/min; and
Step 4: after the mechanical milling, sieving the powder under an inert gas atmosphere in a glovebox to obtain the ODS powder,
wherein the ODS iron-based alloy powder comprises a matrix and strengthening phases; the strengthening phases comprise at least two types of strengthening phase particles with different sizes; the two types of the strengthening phase particles with different sizes are particle A and particle B, a size of the particle A is less than or equal to 50 nm, and a size of the particle B is larger than 50 nm and less than or equal to 200 nm, a volume of the particle A accounts for 85-95% of a total volume of all the strengthening phase particles, and a content of the strengthening phases is 0.5-3.0 wt. %,
wherein the matrix is a Fe—Cr—W—Ti alloy,
wherein the strengthening phases comprise crystalline Y 2 O 3 , amorphous Y 2 O 3 , Y—Ti—O, Y—Cr—O and Y—W—O.

2. The method of preparing the ODS iron-based alloy powder according to claim 1 , wherein
two gas nozzles are disposed on a lid of the milling can for vacuuming and filling with the inert gas after closing;
the inert gas is argon;
the ball milling machine is a vertical planetary ball milling machine or an omni-directional planetary ball milling machine, and revolution and rotation directions are changed once per 25-35 min during ball milling.

3. The method of preparing the ODS iron-based alloy powder according to claim 1 , wherein
a particle size of the rare earth oxide powder containing Y 2 O 3 is less than or equal to 75 μm, and the pre-alloyed iron-based powder is Fe—Cr—W—Ti alloy powder with a particle size of less than or equal to 150 μm.

Assignees

• Univ Central South

Inventors

• Liu Zuming
• Li Quan
• Huang Boyun
• Lv Xueqian
• Peng Kai
• Zhao Fan

Classifications

• C22C33/0292 Primary

  with more than 5% preformed carbides, nitrides or borides · CPC title

• C22C38/22 Primary

  with molybdenum or tungsten · CPC title

• G01N23/2251

  using incident electron beams, e.g. scanning electron microscopy [SEM] · CPC title

• C22C38/28

  with titanium or zirconium · CPC title

• C22C33/0207

  Using a mixture of pre-alloyed powders or a master alloy · CPC title