A high-performance powder metallurgy pressed sintered semi-high-speed steel and its preparation method

A technology of powder metallurgy pressing and semi-high-speed steel, which is applied in the field of high-performance powder metallurgy pressing and sintering semi-high-speed steel and its preparation, and can solve problems such as composition segregation and structure deterioration

Active Publication Date: 2021-05-11
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Aiming at the deficiencies of the current technology, the object of the present invention is to provide a high-performance powder metallurgy pressed sintered semi-high-speed steel and its preparation method. The method uses carbonyl iron powder and carbide powder as raw materials, which are mixed by ball milling, pressed into shape, Sintering densification and other steps to prepare semi-high-speed steel, because the powder metallurgy technology does not require melting, avoiding the problems of composition segregation and structure deterioration in the preparation process of melting casting method, and by directly adding carbide powder, it can ensure that the provided semi-high-speed steel has Microstructure with fine grains and dispersed carbides, with excellent strength and toughness

Method used

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  • A high-performance powder metallurgy pressed sintered semi-high-speed steel and its preparation method
  • A high-performance powder metallurgy pressed sintered semi-high-speed steel and its preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0035] 93.48wt.% carbonyl iron powder, 0.54wt.% WC powder, 2.13wt.% Mo 2 C powder, 2.37wt.%Cr 2 C 3 Powder, 1.48wt.% VC powder is placed in a planetary ball mill container for high-speed ball milling. The material of the tank and the balls are hard alloy. The ball-to-material ratio is 8:1. Water and ethanol; then, add 0.5wt.% paraffin powder into the ball mill jar, and continue ball milling for 4 hours at a speed of 200r / min.

[0036] Then pour the ball-milled powder into a tray, lay it flat and place it in an oven for blast drying at a drying temperature of 70°C and a drying time of 90 minutes, and then pass the powder through a 100-mesh sieve for granulation to obtain a fully dried mixture .

[0037] The mixed material was weighed and formed in a mold, and bidirectional pressing was adopted, with a pressing pressure of 600 MPa and a holding time of 3 s, and then demoulding to obtain a green compact.

[0038] Put the compact into a hydrogen atmosphere sintering furnace fo...

Embodiment 2

[0043] 88.04wt.% carbonyl iron powder, 1.08wt.% WC powder, 3.19wt.% Mo 2 C powder, 4.73wt.%Cr 2 C 3 Powder, 2.96wt.% VC powder is put into the planetary ball mill container for high-speed ball milling. The material of the tank and the balls are hard alloy. The ball-to-material ratio is 9:1. water and ethanol; then, add 1.0wt.% paraffin powder into the ball mill jar, and continue ball milling for 5 hours at a speed of 230r / min.

[0044] Then pour the ball-milled powder into a tray, lay it flat and place it in an oven for blast drying at a drying temperature of 75°C and a drying time of 110 minutes, and then pass the powder through a 100-mesh sieve for granulation to obtain a fully dried mixture .

[0045] The mixed material was weighed and formed in a mold, and bidirectional pressing was adopted, with a pressing pressure of 650 MPa and a holding time of 4 s, and then demolded to obtain a green compact.

[0046] Put the compact into a hydrogen atmosphere sintering furnace fo...

Embodiment 3

[0051] 83.12wt.% carbonyl iron powder, 1.62wt.% WC powder, 3.72wt.% Mo 2 C powder, 7.10wt.%Cr 2 C 3 Powder, 4.44wt.% VC powder is put into the planetary ball mill container for high-speed ball milling. The material of the tank and the balls are hard alloy, the ball-to-material ratio is 10:1, the ball milling time is 50h, the speed is 250r / min, and the ball milling medium is none Water and ethanol; subsequently, 1.5wt.% paraffin powder was added into the ball mill jar, and ball milling was continued for 6 hours at a speed of 250r / min.

[0052] Then pour the ball-milled powder into a tray, lay it flat and place it in an oven for blast drying at a drying temperature of 80°C and a drying time of 120 minutes, and then pass the powder through a 100-mesh sieve for granulation to obtain a fully dried mixture .

[0053] The mixed material was weighed and formed in a mold, and bidirectional pressing was adopted, with a pressing pressure of 700 MPa and a holding time of 5 s, and then ...

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Abstract

The invention discloses a high-performance powder metallurgy pressed and sintered semi-high-speed steel and a preparation method thereof. The invention uses carbonyl iron powder and carbide powder as raw materials, and realizes the preparation of high-performance powder metallurgy semi-high-speed steel through processes such as ball milling, cold pressing, thermal degreasing and vacuum sintering. The prepared semi-high-speed steel has uniform chemical composition, fine grains, and overall dispersed distribution of carbides, which avoids the problems of composition segregation and coarse carbides in the traditional casting method, and significantly improves the strength and toughness of the material. The invention has the advantages of simple technological process, low production cost, easy control of components and the like. Compared with the semi-high-speed steel prepared by melting and casting, the provided semi-high-speed steel has significantly improved bending strength and impact toughness under the same density.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy high-speed steel manufacturing, and in particular relates to a high-performance powder metallurgy pressed and sintered semi-high-speed steel and a preparation method thereof. Background technique [0002] Semi-high-speed steel is developed on the basis of full-speed steel by reducing the content of alloy elements. Compared with full-speed steel, semi-high-speed steel maintains a high matrix quenching and tempering hardness, and has high strength, high toughness, and high wear resistance. It is widely used in the roll body of the roll and the blade of the paper cutting blade. It is a tool and mold material with good development prospects. At present, melting casting method is a common preparation method for semi-high-speed steel materials. Chinese patent [CN 105586541 A] discloses "a method for preparing semi-high-speed steel". This method prepares semi-high-speed steel materials suitabl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/22C22C38/24C22C33/02
CPCC22C33/006C22C33/0235C22C33/0285C22C38/22C22C38/24
Inventor 刘如铁杨军浩熊翔陈洁汪琳廖宁
Owner CENT SOUTH UNIV
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