CN112813358B

CN112813358B - Preparation method of material for flange

Info

Publication number: CN112813358B
Application number: CN202011626039.6A
Authority: CN
Inventors: 马瑞辉; 龚海珊; 邓启富; 苏镇坚
Original assignee: Guangdong Nbtm New Materials Co ltd
Current assignee: Guangdong Nbtm New Materials Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-06-17
Anticipated expiration: 2040-12-30
Also published as: CN112813358A

Abstract

The invention relates to a preparation method of a material for a flange, which comprises the following raw materials in percentage by mass: 93-97% of iron, 0.7-1.0% of carbon, 1.5-2.0% of copper, 0.2-0.4% of manganese sulfide, 0.1-0.5% of wax and the balance of molybdenum powder, wherein the preparation method comprises the following steps: s1, blending, forming and sintering iron, copper, carbon, manganese sulfide and molybdenum powder to obtain a crude product; s2, heating the crude product by using steam for 2-6h, then cooling by using air, and cooling to room temperature; s3, under the same conditions as those of the step S2, heating the product obtained in the step S2 again by using water vapor for 2-6h to obtain the material for the flange. The invention has the beneficial effects that: the water vapor is treated twice in a short time to replace the single long-time water vapor treatment in the prior art, so that the air tightness of parts is improved.

Description

Preparation method of material for flange

Technical Field

The invention belongs to the field of flange preparation, and particularly relates to a preparation method of a material for a flange.

Background

The formal implementation of GB21455-2019 'energy efficiency limit value and energy efficiency grade' of a room air conditioner from 7/1 in 2020, means that the existing constant-frequency air conditioners with low energy efficiency and high power consumption are eliminated. Relevant data show that the market elimination rate of the current fixed-frequency air conditioner can reach more than 45% by the implementation of the new national standard.

In order to meet the current new national standard, manufacturers are required to carry out structural optimization on parts of products fundamentally, so that the energy-saving and consumption-reducing performances of products such as air conditioners and the like are realized. The key parts of the air conditioner comprise flanges, and the flanges prepared by the prior art mainly have the following defects: (1) the material is basically iron-carbon-copper, the structure is basically pearlite and austenite, and the mechanical property is relatively common; (2) the long-time water vapor of use single handles the hole sealing, and the hole sealing effect is comparatively general. This is not favorable to realizing the energy saving and consumption reduction performance of products such as air conditioners.

Therefore, how to optimize the preparation method related to the flange and improve the mechanical property, the air tightness and the service life of the flange is realized, so that the flange is beneficial to the optimization of the aspects of energy conservation and consumption reduction of the air conditioner after being applied to the air conditioner, and has positive and profound significance.

Disclosure of Invention

The invention aims to provide a preparation method of the material for the flange, and the raw materials of the material for the flange comprise the following components in percentage by mass: 93-97% of iron, 0.7-1.0% of carbon, 1.5-2.0% of copper, 0.2-0.4% of manganese sulfide, 0.1-0.5% of wax and the balance of molybdenum powder, wherein the preparation method is realized by the following technical scheme:

s1, blending, molding and sintering iron, copper, carbon, manganese sulfide and molybdenum powder to obtain a crude product;

s2, heating the crude product by steam for 2-6h, then cooling by air, and cooling to room temperature.

S3, under the same conditions of the S2 step, the product obtained in the S2 step is heated by steam again for 2-6h, and the material for the flange is obtained.

Specifically, the crude product is placed according to a certain mode, the crude product is placed into a steam treatment furnace through a crane, a valve is closed, the air pressure in the furnace is adjusted, the air pressure is set to be 38KPa, the temperature in the furnace is raised, oil or water possibly existing in the product manufacturing process is volatilized, the crude product is preheated at the same time, the temperature of the crude product is close to the temperature in the furnace, then a steam generator generates steam, the heated high-temperature steam is introduced into the furnace from the bottom of the steam treatment furnace, the temperature in the furnace is continuously raised, the product starts to react, and ferroferric oxide (Fe 3O 4) is generated in product pores; and repeating the steps for 1-3 times, discharging the crude product, air cooling, and transferring to the next procedure after the crude product is qualified.

Further, in the step S1, the sintering temperature is 1100-1150 ℃.

Further, in the step S2, the heating temperature of the water vapor is 530 ℃ to 590 ℃.

Further, in the step S2, the heating time of the water vapor is 3-6 h.

Further, the step S2 is performed in a steam treatment furnace.

The invention has the beneficial effects that:

the water vapor is treated twice in a short time to replace the single long-time water vapor treatment in the prior art, so that the air tightness of parts is effectively improved.

Drawings

Fig. 1(a) shows a gold phase diagram of the material for a flange of example 1; fig. 1(b) shows a gold phase diagram of the material for a flange in comparative example 1.

Fig. 2(a) shows a pore pattern of a product surface of the material for a flange of comparative example 1; fig. 2(b) shows a pore diagram of the inside of a product of the material for a flange of comparative example 1;

FIG. 2(c) is a diagram showing the porosity of the product surface of the material for flanges of example 1 after the first steam treatment; FIG. 2(d) is a diagram showing pores inside the product of the material for a flange after the first steam treatment of example 1;

FIG. 2(e) shows a pore pattern of the product surface of the material for a flange after the second water vapor treatment of example 1; fig. 2(f) shows a pore pattern of the inside of the product of the material for a flange after the second water vapor treatment of example 1.

Detailed Description

In order to more clearly illustrate the technical solution of the present invention, the following examples are given. The starting materials, reactions and work-up procedures which are given in the examples are, unless otherwise stated, those which are customary on the market and are known to the person skilled in the art.

In the embodiment of the invention, the wax is purchased from Guangzhou Bright trade company Limited and has the model ZS-1000F;

the steam treatment furnace was purchased from the Istet heating Equipment Co., Ltd, and was of the type STF.

Example 1

The material for the flange comprises the following components in percentage by mass:

iron content 93%

Carbon 0.7%

1.5 percent of copper

0.2 percent of manganese sulfide

0.1 percent of wax

The balance of molybdenum powder

The preparation method of the material for the flange comprises the following steps:

s1, according to the mass fraction, carrying out physical blending on iron, carbon, copper, manganese sulfide and molybdenum powder in a double-cone mixer for 30min, and sieving by a 80-mesh sieve;

then conveying the obtained powder into a corresponding die cavity for pressing and forming to obtain a blank;

placing the green part in a mesh belt type sintering furnace, and sintering for 3h at 1120 ℃ to obtain a crude product;

s2, placing the crude product in a steam treatment furnace, introducing steam of 530 ℃ into the furnace through the furnace bottom, heating the crude product by the steam for 6 hours, and cooling the crude product to room temperature by air outside the furnace;

s3 the product obtained in the S2 step was again subjected to steam heating under the same conditions as described in the above-mentioned S2 step, except that the duration was 2h, to obtain a material for flanges.

Example 2

iron content is 95%

0.8 percent of carbon

Copper 1.7%

0.3 percent of manganese sulfide

0.4 percent of wax

The balance of molybdenum powder.

s1, according to the mass fraction, physically blending iron, carbon, copper, manganese sulfide and molybdenum powder in a double-cone mixer for 30min, and sieving the mixture by a sieve of 80 meshes;

placing the green part in a mesh belt type sintering furnace, and sintering for 3h at 1150 ℃ to obtain a crude product;

s2, placing the crude product in a steam treatment furnace, introducing 560 ℃ steam into the furnace through the furnace bottom, heating the crude product for 2 hours, then cooling the crude product by air outside the furnace, and cooling the crude product to room temperature;

s3 the product obtained in the S2 step was again subjected to steam heating under the same conditions as described in the above-mentioned S2 step, except that the duration was 6 hours, to obtain a material for flanges.

Comparative example 1

Comparative example 1 the composition and preparation method were the same as those of example 1 except that the raw material of the material for flange in comparative example 1 did not contain molybdenum powder.

Comparative example 2

Comparative example 2 the composition and preparation method were the same as in example 1 except that the preparation method of example 1 was not used in the preparation method of the material for a flange in comparative example 2, but the crude product was subjected to a one-time steam heating treatment at a steam temperature of 530 c for a total duration of 8 hours.

Test example

The samples obtained in example 1 and comparative examples 1 to 2 were subjected to a performance test in which the metallographic test of the samples was carried out by cutting the samples into small pieces and setting the pieces in a metallographic mosaicing machine for mosaicing. After the inlaying was completed, rough grinding, finish grinding, polishing, etching with 1.5% nitric acid, and observing the metallographic phase with a microscope.

Fig. 1(a) shows a gold phase diagram of the material for a flange of example 1, and fig. 1(b) shows a gold phase diagram of the material for a flange in comparative example 1. As can be seen from the figure, in the gold phase diagram of example 1, pearlite grains are fine without distinct boundaries, wherein part of the crystals are converted into bainite with finer grains; in contrast, in the gold phase diagram of comparative example 1, pearlite is in the form of flakes and the crystals are coarse. From the gold phase diagrams of the two formulas, the molybdenum element promotes the carbide transformation of iron, refines the metallographic structure and transforms part of the structure into bainite, thereby improving the mechanical property of the product.

The pore map of the sample is tested by the following method: and cutting the product into small blocks, and embedding the small blocks in a metallographic embedding machine. After the inlaying is finished, coarse grinding, fine grinding and polishing are carried out, and then a metallographic phase is observed by a microscope.

Fig. 2(a) shows a pore pattern of a product surface of the material for a flange of comparative example 2, and fig. 2(b) shows a pore pattern of the inside of the product of the material for a flange of comparative example 2, illustrating that the thickness of the water vapor treatment layer is 0.009mm at the product surface; from the pore diagram of the product, a small part of the pores are not completely wrapped and filled by the water vapor treatment layer.

Fig. 2(c) shows a diagram of the porosity of the product surface of the material for flanges after the first water vapor treatment of example 1, and fig. 2(d) shows a diagram of the porosity of the product interior of the material for flanges after the first water vapor treatment of example 1, illustrating that the water vapor treatment layer has a thickness of 0.006mm, which is thinner than that of comparative example 2, at the product surface; from the pore diagram of the product, a part of the pores are not completely wrapped and filled by the water vapor treatment layer.

FIG. 2(e) is a diagram showing the porosity of the product surface of the material for flanges of example 1 after the second water vapor treatment, and FIG. 2(f) is a diagram showing the porosity of the inside of the product of the material for flanges of example 1 after the second water vapor treatment, illustrating that the water vapor treatment layer has a thickness of 0.01 to 0.011mm, which is thicker than that of comparative example 2, at the product surface; from the pore diagram of the product, all pores are completely wrapped and filled by the water vapor treatment layer.

As can be seen from fig. 2(a) - (f), the surface water vapor treated layer of the twice water vapor treated product is thicker than that of the single water vapor treated product; from the view of gaps, the hole sealing effect of the two-time water vapor treatment is obviously better than that of a product treated by single-time water vapor, and basically all the gaps are completely wrapped and filled by the water vapor treatment layer. The hole sealing effect is improved, and the air tightness is correspondingly improved.

The mechanical property test of the sample adopts the following method: tensile bar method: and pressing the tensile test bar by using the powder material with the corresponding formula, and testing the mechanical property of the tensile test bar.

The method for testing the service life of the sample comprises the following steps: testing according to the national standard GBT15765 full-closed motor for room air conditioner;

the method for testing the air tightness of the sample comprises the following steps: and (3) placing the product into an air tightness testing tool by adopting an air tightness detecting instrument, ventilating and pressurizing for 3 minutes, and testing the pressure of the product during air leakage.

The relevant test data are shown in table 1.

TABLE 1 data of Performance test of examples 1-2 and comparative examples 1-2

	Mechanical properties (tensile strength/MPa)	Life test (hours)	Airtightness (MPa)
				Example 1	510.3	1715	2.38
Example 2	515.7	1731	2.35
				Comparative example 1	461.8	1594	2.33
Comparative example 2	502.1	1689	2.04

The above data fully illustrate that: after the molybdenum powder is added, the mechanical property and the service life of the sample are obviously improved. In addition, under the condition that the total time for heating the crude product by the steam is the same, the steam heats the crude product twice, and compared with the steam for heating the crude product once, the indexes of mechanical property, service life, air tightness and the like of the sample obtained by the steam heating method are better.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description is described in terms of embodiments, not every embodiment includes only a single technical solution as a whole, and technical solutions in various embodiments may be appropriately combined to form other embodiments as will be understood by those skilled in the art.

Claims

1. The preparation method of the material for the flange comprises the following raw materials in percentage by mass: 93-97% of iron, 0.7-1.0% of carbon, 1.5-2.0% of copper, 0.2-0.4% of manganese sulfide, 0.1-0.5% of wax and the balance of molybdenum powder, and is characterized in that the preparation method comprises the following steps:

s2, heating the crude product by water vapor for 2-6h, then cooling by air, and cooling to room temperature;

2. The method for preparing a material for a flange according to claim 1, wherein the sintering temperature in the step of S1 is 1100-1150 ℃.

3. The method for preparing a material for a flange according to claim 1, wherein the temperature of heating the water vapor is 530-590 ℃ in the step of S2.

4. The method for preparing a material for a flange according to claim 1, wherein the heating time of the water vapor is 3 to 6 hours in the step of S2.

5. The method for preparing a material for a flange according to claim 1, wherein the step of S2 is performed in a steam treatment furnace.