Method for preparing toughened 24 CrNiMo alloy steel through selective laser melting technology

A technology of laser selective melting and alloying steel, applied in the field of materials, can solve problems such as poor toughness, achieve the effect of reducing cracks, simple and reliable method, and improving the matching relationship between strength and toughness

Active Publication Date: 2017-12-22
NORTHEASTERN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In view of the generally poor toughness of alloy steel components prepared by laser selective melting technology, the purpose of the present invention is to provide a material for preparing toughened 24CrNiMo alloy steel by laser selective melting technology and greatly improve the production efficiency of laser selective melting technology. Methods of Toughness of 24CrNiMo Alloy Steel

Method used

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  • Method for preparing toughened 24 CrNiMo alloy steel through selective laser melting technology
  • Method for preparing toughened 24 CrNiMo alloy steel through selective laser melting technology
  • Method for preparing toughened 24 CrNiMo alloy steel through selective laser melting technology

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] The toughened 24CrNiMo alloy steel parts are prepared by laser selective melting technology, and the specific steps are as follows:

[0043] Step 1: Preparation of Composite Powder

[0044] (1) According to the mass percentage CeO 2 Powder: 24CrNiMo powder = 0.1:99.9, weigh CeO 2 Powder and 24CrNiMo alloy steel powder are put into a ball mill tank containing ball abrasives, the material ratio is 1:8 (that is, the mass ratio of ball abrasives to powder to be ground is 1:8), and put into QM-5 experimental liquid cylinder In the ball mill, the input voltage is 220V / 50Hz, the power is 370W, and the speed is 405r / min. Mix for 6 hours to get 24CrNiMo / CeO 2 Composite powder; the ball abrasive is a steel ball with a particle size of 5-10mm;

[0045] Wherein the 24CrNiMo alloy steel powder is composed of the following alloy elements according to the mass percentage: C: 0.20%, Cr: 0.97%, Ni: 0.95%, Mo: 0.45%, Mn: 0.90%, Si: 0.35%, O: 0.18%, the balance is Fe; the CeO 2 The p...

Embodiment 2

[0068] Preparation of CeO by Selective Laser Melting Technology 2 Toughening 24CrNiMo alloy steel, preparation method is the same as embodiment 1, and wherein difference is:

[0069] In (1) of step 1, CeO 2 The mass ratio of powder to 24CrNiMo powder is CeO 2 Powder: 24CrNiMo powder = 0.4:99.6; the material ratio during ball milling is 1:9, and the mixing time is 7 hours in the ball mill drum machine; 24CrNiMo alloy steel powder is composed of the following alloy elements according to the mass percentage: C: 0.24% , Cr: 1.00%, Ni: 0.99%, Mo: 0.51%, Mn: 1.01%, Si: 0.40%, O: 0.19%, and the balance is Fe.

[0070] In (2) of step 1, the composite powder is kept at 90° C. for 3 hours in a vacuum oven for drying.

[0071] In (1) of step 2, the layer thickness during layered discrete processing of the 3D model is set to 0.7mm.

[0072] In (2) of step 2, the laser selective melting process parameters: the laser output power P is 2100W, the laser beam scanning speed V is 10mm / s, an...

Embodiment 3

[0088] Preparation of CeO by Selective Laser Melting Technology 2 Toughening 24CrNiMo alloy steel, preparation method is the same as embodiment 1, and wherein difference is:

[0089] In (1) of step 1, CeO 2 The mass ratio of powder to 24CrNiMo powder is CeO 2 Powder: 24CrNiMo powder = 0.7:99.3; the material ratio during ball milling is 1:10, and the mixing time is 8 hours in the ball mill drum machine; 24CrNiMo alloy steel powder is composed of the following alloy elements according to the mass percentage, C: 0.26 %, Cr: 1.02%, Ni: 1.01%, Mo: 0.55%, Mn: 1.02%, Si: 0.50%, O: 0.20%, and the balance is Fe;

[0090] In (2) of step 1, the composite powder is kept at 100° C. for 2 hours in a vacuum oven for drying.

[0091] In (1) of step 2, the layer thickness during the layered discrete processing of the 3D model is set to 0.8mm.

[0092] In (2) of step 2, the laser selective melting process parameters: the laser output power P is 2300W, the laser beam scanning speed V is 12mm...

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Abstract

The invention relates to a method for preparing toughened 24 CrNiMo alloy steel through a selective laser melting technology. The method is characterized in that 24CrNiMo / CeO2 composite powder with a determined mass ratio and a uniform phase is prepared through mechanical ball-milling; and an alloy steel component is quickly formed layer by layer according to a predetermined selective laser melting path and process parameters. Through actions of refining crystalline grains, purifying a molten pool and the like in the laser molten pool through CeO2, samples which have small structures and are free of obvious defects such as cracks and pores are formed; and a selective laser melting process with large power, a great powder paving thickness and lower scanning speed is adopted, so that the forming rate is increased. A 24CrNiMo alloy steel component has room-temperature tensile strength of 10000 MPa level, and has ductility of 20-26%, so that strength and toughness of 24 CrNiMo alloy steel prepared by the selective laser melting technology are improved. The method is mainly applied to laser additive manufacturing of a 24 CrNiMo alloy steel high-speed railway brake disc.

Description

technical field [0001] The invention belongs to the field of material technology, in particular to a laser selective melting technique for preparing CeO 2 Method for toughening 24CrNiMo alloy steel. technical background [0002] High-speed rail brake discs are one of the key components to ensure the reliable operation of high-speed trains. Brake disc materials must have high friction coefficient stability, high-temperature composition stability, and sufficient mechanical strength and toughness to prevent premature cracks in the brake disc, etc. defect. Cr-Ni-Mo low-alloy high-strength steel has good strength and toughness and high heat resistance, and 24CrNiMo alloy steel is currently commonly used steel for high-speed train brake discs. The traditional manufacturing method of brake discs has problems such as long production cycle, high manufacturing cost, and complicated heat treatment process. At the same time, the core technology is monopolized by foreign countries and ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/105B22F1/00C22C38/44C22C38/04C22C38/02F16D65/12B33Y30/00B33Y70/00B33Y80/00
CPCB22F1/0003F16D65/125C22C38/02C22C38/04C22C38/44B33Y30/00B33Y70/00B33Y80/00F16D2200/0021B22F2998/10B22F10/00B22F10/34B22F10/28B22F10/36B22F10/366B22F10/32B22F2009/043Y02P10/25
Inventor 陈岁元邓育灵魏明炜王瑞雪刘常升梁京崔彤
Owner NORTHEASTERN UNIV
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