Warm press forming method in high density and low temperature for powder of stainless steel

A warm-pressing, stainless steel technology, applied in the field of powder metallurgy, can solve the problems of high price, large investment in warm-pressing production line equipment, and strict operating temperature requirements, achieving low cost, good formability and compressibility, and long service life. long effect

Inactive Publication Date: 2005-08-31
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These patent-protected powders are not only very expensive, but also have very strict requirements on the operating temperature, that is, the temperature range is required to be controlled at ±2°C, which requires a specific temperature-pressure system to complete, and these temperature-pressure systems are subject to Patent protection, so the equipment investment of the temperature and pressure production line is very large

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Embodiment 1: Low-temperature warm-press forming method of 316L stainless steel powder

[0020] Its warm-pressing process and its conditions include:

[0021] 1. Use domestic ≤147μm water to atomize 316L stainless steel powder, add 0.1% polyethylene wax powder as a low-temperature lubricant according to the total mass percentage, and then dry mix it on a V-type mixer for 15 minutes;

[0022] 2. Heat the above-mentioned 316L stainless steel powder mixed with lubricant to 90°C;

[0023] 3. Heat the mold to 100°C, and electrostatically spray EBS wax powder on the inner cavity of the mold;

[0024] 4. Fill the mold with heated 316L stainless steel powder mixed with lubricant, and press it at 800MPa;

[0025] 5. Sinter at 1300°C for 1 hour in an atmosphere of decomposed ammonia.

[0026] You can get 316L stainless steel green body density up to 7.15g / cm 3 , which is 0.30g / cm higher than the conventional cold-pressed green density 3 ; The green strength reaches 35MPa, wh...

Embodiment 2

[0027] Embodiment 2: Low-temperature warm-press forming method of 304L stainless steel powder

[0028] Its warm-pressing process and its conditions include:

[0029] 1. Use domestic ≤147μm water atomization 304L stainless steel powder, and add 0.3% long-chain fatty acid diamide wax powder as a low-temperature lubricant according to the total mass percentage, and then dry mix it on a type mixer for 25 minutes;

[0030] 2. Heat the 304L stainless steel powder mixed with lubricant to 70°C;

[0031] 3. Heat the mold to 80°C, and electrostatically spray EBS wax powder on the inner cavity of the mold;

[0032] 4. Fill the mold with heated 304L stainless steel powder, and press it under 600MPa;

[0033] 5. Sinter at 1300°C for 1.5 hours in an atmosphere of decomposed ammonia.

[0034] You can get 304L stainless steel green body density up to 7.05g / cm 3 , which is 0.22g / cm higher than the conventional cold-pressed green density 3 ; The green strength reaches 28MPa, which is 18% h...

Embodiment 3

[0035] Embodiment 3: Low-temperature warm-press forming method of 410L stainless steel powder

[0036] Its warm-pressing process and its conditions include:

[0037] 1. Use domestic ≤147μm water atomization 410L stainless steel powder, and add 0.1% polyethylene wax powder and 0.1% long-chain fatty acid diamide wax powder as low-temperature lubricant according to the total mass percentage, and then in the V-type mixing Dry mixing on the feeder for 30 minutes;

[0038] 2. Heat the 410L stainless steel powder mixed with lubricant to 80°C;

[0039] 3. Heat the mold to 100°C, and electrostatically spray EBS wax powder on the inner cavity of the mold;

[0040] 4. Fill the mold with heated 410L stainless steel powder, and press it under 700MPa;

[0041] 5. Sinter in a vacuum furnace at 1250°C for 1 hour.

[0042] You can get 410L stainless steel green body density up to 6.80g / cm 3 , which is 0.12g / cm higher than conventional cold-pressed green density 3 ; The green strength rea...

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Abstract

A low-temp pressing technology for manufacturing high-density stainless steel part by power metallurgy of stainless steel powder (less than 147 microns in granularity) includes proportionally mixing stainless steel powder with low-temp lubricant, heating die to 80-100 deg.C, spraying EBS wax powder onto inner surface of die by electrostatic spray, preheating said mixture to 70-90 deg.C, loading it in die, and die pressing under 600-800 MPa.

Description

technical field [0001] The invention relates to powder metallurgy technology, in particular to a high-density low-temperature warm-press forming method of stainless steel powder. Background technique [0002] The advantage of using the traditional powder metallurgy method to produce stainless steel parts is that it can produce final shape or near-net shape powder metallurgy parts at a lower cost, which can realize less cutting and no machining, but the disadvantage is that the density of the parts is not high, and the corrosion resistance and mechanical properties are reduced. . Although the stainless steel parts produced by isostatic pressing and injection molding have high density, their application is greatly limited due to the complicated process and high cost. The warm-pressing process, which was successfully developed in the 1990s and has been industrialized, not only overcomes the shortcomings of low part density, but also has the advantages ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/16
Inventor 肖志瑜张菊红李元元夏伟罗宗强吴苑标
Owner SOUTH CHINA UNIV OF TECH
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