Additive used for improving stainless steel sintered density and method for manufacturing relevant stainless steel sintered component with additive

A technology of sintering density and additives, which is applied in the field of powder metallurgy, can solve the problems of high energy costs and achieve the effect of increasing the pressing density and scientific and reasonable formula

Active Publication Date: 2016-06-08
NBTM NEW MATERIALS GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] With the continuous development of powder metallurgy technology, technologies such as warm pressing, mold wall lubrication and super solid phase sintering can eliminate these residual voids to a large extent and increase the strength of the material, but the parts must be fully dense or more than 98.5% dense , it needs to be sintered at a higher temperature for a long time, of course, the problem of high energy costs must be considered, and the need for a special high-temperature furnace is also a problem

Method used

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  • Additive used for improving stainless steel sintered density and method for manufacturing relevant stainless steel sintered component with additive
  • Additive used for improving stainless steel sintered density and method for manufacturing relevant stainless steel sintered component with additive
  • Additive used for improving stainless steel sintered density and method for manufacturing relevant stainless steel sintered component with additive

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Use 434L series atomized stainless steel powder as the base powder, add ordinary high-temperature lubricants accounting for 0.4% of the base powder mass, mechanically stir evenly, and use it as a spare material.

[0027] Prepare the additive, the steps are as follows: weigh the required Fe by 3% of the base powder mass 3 P alloy is also based on the quality of the base powder, weighing 0.1% of its mass of lauric acid (abbreviated as LA) and 0.2% of its mass of malic acid (MA), mixed into Fe 3 Into the P alloy powder, drop a small amount of solvent—absolute ethanol, preferably to dissolve MA, stir evenly, and dry to obtain the sintering additive.

[0028] Mix the above-mentioned sintering aid additives into the stainless steel base powder equipped with ordinary lubricants, and mix them in a V-type mixer for 0.5 hours. In this way, the stainless steel powder to be pressed with the lubricating effect of the mold wall is ready to be completed.

[0029] As a comparison, ad...

Embodiment 2

[0036] The 434L series stainless steel powder to be pressed powder configured in Example 1 is pressed and formed with standard impact test bar mold, tensile test bar mold and block density test bar mold respectively, and the pressing pressure is all controlled at 600MPa. Rods were placed in the same batch in an argon-protected vacuum sintering furnace for densification and sintering. The sintering temperatures were 1220°C and 1310°C respectively, and the sintering holding time was 40 minutes. / min. Forced cooling after sintering.

[0037] After the preparation of the above samples is completed, the corresponding density and mechanical analysis test rods are taken to test various performance indicators, and the results are recorded in Table 2 below.

[0038] Table 2434L stainless steel sintering properties and additives

[0039]

[0040]

[0041] Due to the sintering promotion effect of additives, the density of stainless steel sintered body has been greatly improved, s...

Embodiment 3

[0043] Use 316L atomized stainless steel powder as the base powder, add ordinary high-temperature lubricant accounting for 0.4% of the base powder mass, mechanically stir evenly, and use it as a spare material.

[0044] Prepare the additive, the steps are as follows: weigh the required Fe by 5% of the mass of the base powder 3 P alloy, the particle size is 7μm, and the quality of the base powder is also used as the standard. Weigh 0.1% of its mass of lauric acid (abbreviated as LA) and 0.2% of its mass of malic acid (MA), and mix it into Fe 3In the P alloy powder, heat and stir evenly until the organic acid is completely melted and coated on the stainless steel powder, then cool down and dry.

[0045] The 316L stainless steel base powder that has been equipped with ordinary lubricants is mixed with the above-mentioned additives, and mixed in a V-shaped mixer for 0.5 hours. In this way, the preparation of the pressed stainless steel powder is completed.

[0046] In the same w...

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Abstract

The invention discloses an additive used for improving the stainless steel sintered density and a method for manufacturing a stainless steel sintered component with the additive. The additive is composed of low-melting-point ferroalloy powder, low-carbon organic acid matter and low-temperature lubricant. After the additive is added to stainless steel powder, the stainless steel powder is pressed under the pressure of 600-900 MPa, and the component is sintered at the temperature of 1200-1350 DEG C. Fast temperature-rising is adopted when the temperature-rising period is 600 DEG C or above, and the temperature-rising rate is 15-60 DEG C / min. The high-density stainless steel sintered component is obtained after sintering. Due to the fact that low-melting-point organic matter is added, when die pressing is conducted, part of liquid lubricant is generated and diffused to the die wall, so that die wall friction is reduced, and the pressing density of the stainless steel powder is well improved. The stainless steel powder is coated with the organic matter and activated before sintering (600-900 DEG C). Meanwhile, low-melting-point alloy is liquefied during sintering, so that a facilitating function is achieved on sintering of the stainless steel powder. The formula of the additive is scientific and reasonable, so that the pressing density of the stainless steel powder can be effectively improved, and a sintered product has higher density and mechanical performance.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy, in particular to an additive for increasing the sintered density of stainless steel and a method for manufacturing related stainless steel sintered parts. Background technique [0002] Whether powder metallurgy stainless steel parts can replace dense stainless steel parts depends on two main factors: its strength and corrosion resistance. The currently used method for preparing high-density products from stainless steel powder includes compacting the stainless steel powder to about 6.4-6.8 g / cm under a compaction pressure of 600-800 MPa. 3 The density between, and then sintering the obtained green body at high temperature, the temperature sometimes reaches 1400 ° C, such as the flange (support), for 30 minutes, in order to obtain about 7.25g / cm 3 Density. Even so, there is still a certain amount of residual pores inside the structure of powder metallurgy structural parts, which will r...

Claims

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Application Information

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IPC IPC(8): C22C33/02B22F1/00
Inventor 聂军武秦晓冬包崇玺张文军
Owner NBTM NEW MATERIALS GRP
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