CN116445851A - Preparation method of alloy steel low-temperature nitrocarburizing film - Google Patents

Abstract

The invention relates to the technical field of surface treatment of metal materials, in particular to a method for preparing an alloy steel low-temperature nitrogen-carbon-oxygen co-infiltration film, comprising: S1 removing foreign matter on the surface of the part; S2 cleaning the part in an alkaline degreasing and degreasing tank, Then wash them with hot water and cold water respectively; S3 dry the surface moisture of the parts; S4 put the parts in the preheating furnace to preheat; S5 put the parts in the nitriding furnace for nitrocarburizing; S6 put the parts in Carry out salt bath oxidation in the oxidation furnace; S7 wash the parts with cold water and hot water respectively; S8 dry the cleaned parts in the preheating furnace, and polish the surface of the parts; S9 clean the polished parts according to S2 , S3, S4, S6, and S7 steps for secondary oxidation treatment; S10 uses polymer treatment liquid to soak and seal the parts after secondary oxidation; thereby solving the problem of poor wear resistance and poor corrosion resistance of parts made of ferrous metal materials , Low core hardness and poor appearance quality.

Description

A kind of preparation method of alloy steel low temperature nitrogen carbon oxygen co-infiltration film

technical field

The invention relates to the technical field of metal material surface treatment, in particular to a method for preparing an alloy steel low-temperature nitrogen-carbon-oxygen permeation film.

Background technique

As a conventional material, ferrous metal is widely used in daily life and work. Depending on the application environment, it will be in contact with oxygen and water mist in the air during service, or it will be exposed to acid and alkali corrosive media during its work, or as a Force parts are subject to contact stress and wear, etc., which will lead to material failure on the surface of metal materials due to oxidation, corrosion, wear and other reasons, and there are risks such as structural fracture and appearance damage, which restrict their use to a certain extent. Therefore, they must undergo certain surface treatment. In order to improve its corrosion resistance, wear resistance and appearance requirements, it can meet the actual needs of some fields.

At present, the mature ferrous metal surface treatment processes mainly include phosphating treatment, high temperature alkaline oxidation treatment, high temperature nitrogen, carbon and oxygen co-infiltration and other technologies. The poor corrosion resistance and wear resistance of the film formed by phosphating treatment and high-temperature alkaline oxidation treatment have become important factors restricting its use and development. There are mainly the following problems: the film layer formed by phosphating and high-temperature alkaline oxidation Its own corrosion resistance is poor, and it needs to be combined with subsequent oil seal treatment to achieve a certain corrosion resistance. The corrosion resistance performance depends heavily on the porosity of the film layer and the oil seal, and the process is complicated, which reduces production efficiency and increases production costs; Phosphating and high temperature alkaline oxidation The formed film layer is a loose layer with poor wear resistance; in terms of environmental protection, the phosphating treatment is acidic, and the high-temperature alkaline oxidation is alkaline, causing certain pollution to the environment. The main problem of high-temperature carbonitriding is that the hardness of the core of the ferrous metal substrate after this treatment is reduced, which cannot meet the strength requirements; therefore, a surface treatment technology for ferrous metal materials is needed to solve the problem of parts made of ferrous metal materials. Poor wear resistance, poor corrosion resistance, low core hardness and poor appearance quality.

Contents of the invention

The purpose of the present invention is to provide a method for preparing alloy steel low-temperature nitrocarburizing film, which aims to solve the problems of poor wear resistance, poor corrosion resistance, low core hardness and poor appearance quality of parts made of ferrous metal materials. .

In order to achieve the above object, the present invention provides a method for preparing an alloy steel low-temperature nitrocarburizing film, and the specific steps include:

S1 removes foreign matter on the surface of the part;

S2 Clean the parts in an alkaline degreasing and degreasing tank, and then wash them once with hot water and cold water respectively;

S3 blow dry parts surface moisture;

S4 places the part in the preheating furnace to preheat;

S5 places the part in the nitriding furnace for nitrocarburizing;

S6 places the parts in an oxidation furnace for salt bath oxidation;

S7 Wash the parts with cold water and hot water respectively;

S8 Dry the cleaned parts in a preheating furnace and polish the surface of the parts;

S9 performs secondary oxidation treatment on the polished parts according to steps S2, S3, S4, S6, and S7;

S10 Soak and seal the parts after secondary oxidation with polymer treatment solution.

Wherein, the specific steps of removing the foreign matter on the surface of the part are: mechanically polishing with 100 mesh silicon carbide emery to remove the foreign matter attached to the surface of the part such as rust.

Wherein, the specific step of preheating the parts in a preheating furnace is as follows: preheating the dried parts in a preheating furnace at 380-400° C. for 30-40 minutes.

Wherein, the specific steps of placing the parts in a nitriding furnace for nitrocarburizing are: placing the parts in a nitriding furnace at 440-460°C for nitrocarburizing, and the nitrocarburizing time is 120-240 minutes;

Wherein, the specific step of placing the parts in an oxidation furnace for salt bath oxidation is: placing the parts in an oxidation furnace at 400-420°C for salt bath oxidation for 20-40 minutes.

Wherein, the specific steps of drying the cleaned parts in a preheating furnace and polishing the surface of the parts are: drying the cleaned parts in a preheating furnace at 380-400 °C, and then using 80 Use aluminum oxide white corundum to polish the surface of the parts.

A method for preparing an alloy steel low-temperature nitrogen-carbon-oxygen co-infiltration film of the present invention comprises: S1 removing foreign matter on the surface of the part; S2 cleaning the part in an alkaline degreasing and degreasing tank, and then washing it once with hot water and cold water respectively ; S3 dry the surface moisture of the parts; S4 preheat the parts in the preheating furnace; S5 place the parts in the nitriding furnace for nitrocarburizing; S6 place the parts in the oxidation furnace for salt bath oxidation; Wash the parts with cold water and hot water once; S8 put the cleaned parts in the preheating furnace to dry, and polish the surface of the parts; S9 process the polished parts according to the steps of S2, S3, S4, S6 and S7 Secondary oxidation treatment; S10 soaks and seals the parts after secondary oxidation with polymer treatment solution; finally forms a certain thickness of nitrogen, carbon and oxygen co-infiltration layer on the surface of the parts, and the nitriding temperature of the present invention is only 440-460 °C, It can effectively ensure the internal strength and toughness of the material, and solve the problem that materials with low tempering temperature resistance cannot meet the requirements of nitrocarburizing; by controlling the salt bath temperature and processing time, different thicknesses of nitrocarburizing layers can be obtained to meet Different production requirements; after co-infiltration, the surface wear resistance, corrosion resistance, core hardness and appearance quality of the parts are greatly improved, so as to solve the problem of poor wear resistance, poor corrosion resistance and core hardness of parts made of ferrous metal materials. Problems such as low hardness and poor appearance quality.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings that are required in the description of the embodiments or the prior art.

Fig. 1 is a flow chart of a method for preparing an alloy steel low-temperature nitrocarburizing film of the present invention.

Fig. 2 is a metallographic microscope image of 30CrMnMoTiA alloy steel nitrocarburizing;

Figure 3 is a metallographic microscope image of 45 steel nitrocarburizing;

Figure 4 is a metallographic microscope image of ZG50 steel nitrocarburizing;

Fig. 5 is 55FeNiMo powder part nitrocarburizing metallographic micrograph;

Fig. 6 is Ni18Co9Mo5 powder part nitrocarburizing metallographic micrograph;

Fig. 7 is a metallographic microscope image of 20Cr13 stainless steel nitrocarburizing;

Detailed ways

Please refer to FIG. 1 , wherein FIG. 1 is a flow chart of a method for preparing an alloy steel low-temperature nitrocarburizing film according to the present invention.

The invention provides a method for preparing an alloy steel low-temperature nitrogen-carbon-oxygen co-infiltration film, and the specific steps include:

S1 removes foreign matter on the surface of the part;

100-mesh silicon carbide emery is used for mechanical polishing to remove rust and other attached foreign matter on the surface of parts.

S2 Clean the parts in an alkaline degreasing and degreasing tank, and then wash them once with hot water and cold water respectively;

Clean the parts in an alkaline degreasing and degreasing tank at 60-80°C, and then wash them once with hot water and cold water respectively.

S3 blow dry parts surface moisture;

Blow dry the moisture on the surface of the parts to avoid residual stains on the surface of the previous process from affecting the appearance of the parts.

S4 places the part in the preheating furnace to preheat;

Place the dried parts in a preheating furnace at 380-400°C for 30-40 minutes to prepare the temperature for nitriding to reduce deformation and ensure good appearance quality.

S5 places the part in the nitriding furnace for nitrocarburizing;

Nitriding process: place the parts in a nitriding furnace at 440-460°C for nitrocarburizing, and the nitriding time is 120-240min; by adjusting the nitriding temperature and processing time, different thicknesses of the nitriding layer can be obtained.

S6 places the parts in an oxidation furnace for salt bath oxidation;

Oxidation process: Place the parts in an oxidation furnace at 400-420°C for salt bath oxidation for 20-40 minutes to form a black oxide film.

S7 Wash the parts with cold water and hot water respectively;

S8 Dry the cleaned parts in a preheating furnace and polish the surface of the parts;

Dry the cleaned parts in a preheating furnace at 380-400°C, and then use 80-mesh aluminum oxide white corundum to polish the surface of the parts to remove loose oxides on the surface of the co-infiltrated parts.

S9 performs secondary oxidation treatment on the polished parts according to steps S2, S3, S4, S6, and S7;

S10 Soak and seal the parts after secondary oxidation with polymer treatment solution.

The parts after secondary oxidation are soaked and sealed with polymer treatment solution to further improve the appearance quality and corrosion resistance.

The preparation method of a low-temperature nitrocarburizing film for alloy steel described in the present invention finally forms a certain thickness of nitrocarburizing layer on the surface of the part. The nitriding temperature of the present invention is only 440-460°C, which can effectively guarantee The internal strength and toughness of the material solve the problem that materials with low tempering temperature resistance cannot meet the nitrocarburizing problem; by controlling the salt bath temperature and processing time, nitrocarburizing layers of different thicknesses can be obtained to meet different production requirements ; After co-infiltration, the surface wear resistance, corrosion resistance, core hardness and appearance quality of the parts are greatly improved, so as to solve the problem of poor wear resistance, poor corrosion resistance, low core hardness and low core hardness of parts made of ferrous metal materials. Problems such as poor appearance quality; the present invention is a low-temperature nitrocarburizing surface treatment technology, which does not affect the size of the part matrix, and at the same time, the wear resistance and corrosion resistance are far superior to surface phosphating and oxidation treatment, and are also higher in temperature. The carbonitriding process has wider applicability, which is beneficial to product quality assurance and surface high performance acquisition; the present invention has the advantages of simple process, convenient operation, low energy consumption, etc., and is suitable for carbon steel, alloy steel, cast steel, stainless steel, powder Parts (Ni-based, Fe-based) and other metal materials have great social application value for the application of metal material surface treatment technology.

Referring to Fig. 2-Fig. 7, the present invention will be further described in detail below in conjunction with specific implementation cases:

First embodiment:

30CrMnMoTiA alloy steel is used as the workpiece, and nitrocarburizing is carried out according to the process flow chart of the present invention. The nitriding process: 440°C/180min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C/40min. The surface hardness after nitrocarburizing is 794HV0.1; the hardness at 0.2mm on the surface is 390HV0.1, the hardness at the center is 42HRC, and the depth of the white layer is 4um. The metallographic microscope picture is shown in Figure 2.

Second embodiment:

45 steel is used as the workpiece, and nitrocarburizing is carried out according to the process flow chart of the present invention. The nitriding process: 460°C/120min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C/40min. The surface hardness after nitrocarburizing is 560HV0.1; the hardness at 0.2mm on the surface is 350HV0.1, the hardness at the center is 34HRC, and the depth of the white layer is 5um. The metallographic microscope picture is shown in Figure 3.

Third embodiment:

ZG50 steel is used as the workpiece, and nitrogen, carbon and oxygen co-seeding is carried out according to the process flow chart of the present invention. The nitriding process: 460°C/180min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C/40min. The surface hardness after nitrocarburizing is 550HV0.1; the hardness at 0.2mm on the surface is 340HV0.1, the hardness at the center is 33HRC, and the depth of the white layer is 5um. The metallographic microscope picture is shown in Figure 4.

Fourth embodiment:

Fe-based powder (55FeNiMo) is used as the workpiece, and nitrogen, carbon and oxygen co-infiltration are carried out according to the process flow chart of the present invention. The nitriding process: 450°C/180min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C /40min. The surface hardness after nitrocarburizing is 545HV0.1; the hardness at 0.2mm on the surface is 365HV0.1, the hardness at the center is 33HRC, and the depth of the white layer is 3um. The metallographic microscope image is shown in Figure 5.

Fifth embodiment:

Ni-based powder parts (Ni18Co9Mo5) are used as workpieces, and nitrogen, carbon and oxygen co-infiltration are carried out according to the process flow chart of the present invention. The nitriding process: 460°C/180min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C /40min. The surface hardness after nitrocarburizing is 810HV0.1; the hardness at 0.2mm on the surface is 470HV0.1, the hardness at the center is 45HRC, and the depth of the white layer is 3um. The metallographic microscope image is shown in Figure 6.

Sixth embodiment:

20Cr13 stainless steel is used as the workpiece, and nitrocarburizing is carried out according to the process flow chart of the present invention. The nitriding process: 460°C/240min; the primary oxidation process: 400°C/20min; the secondary oxidation process: 420°C/40min. The surface hardness after nitrocarburizing is 920HV0.1; the hardness at 0.2mm on the surface is 430HV0.1, the hardness at the center is 40HRC, and the depth of the white layer is 3um. The metallographic microscope picture is shown in Figure 7.

What is disclosed above is only one or more preferred embodiments of the present application, and should not be used to limit the scope of rights of the present application. Those of ordinary skill in the art can understand all or part of the process of realizing the above embodiments, and according to this The equivalent changes made in the claims of the application still belong to the scope covered by the application.

Claims (6)

1. The preparation method of the alloy steel low-temperature nitrocarburizing film is characterized by comprising the following specific steps:

s1, removing foreign matters on the surface of a part;

s2, cleaning the parts in an alkaline degreasing tank, and then cleaning the parts with hot water and cold water for one time respectively;

s3, drying the surface moisture of the part;

s4, placing the parts in a preheating furnace for preheating;

s5, placing the part in a nitriding furnace for nitrocarburation;

s6, placing the parts in an oxidation furnace for salt bath oxidation;

s7, cleaning the parts with cold water and hot water for one time respectively;

s8, placing the cleaned part in a preheating furnace for drying, and polishing the surface of the part;

s9, performing secondary oxidation treatment on the polished part according to the steps S2, S3, S4, S6 and S7;

s10, soaking and sealing the parts subjected to secondary oxidation by adopting a polymer treatment liquid.

2. The method for preparing the alloy steel low-temperature nitrocarburizing and oxycarbide co-penetrating film according to claim 1, which is characterized in that,

the specific steps of removing the foreign matters on the surface of the part are as follows: and (3) mechanically polishing by adopting 100-mesh silicon carbide to remove adhering foreign matters such as rust on the surface of the part.

3. The method for preparing the alloy steel low-temperature nitrocarburizing and oxycarbide co-penetrating film according to claim 2, which is characterized in that,

the specific steps of preheating the parts in the preheating furnace are as follows: and (3) placing the parts subjected to the drying of the water in a preheating furnace at 380-400 ℃ for preheating for 30-40min.

4. The method for preparing the alloy steel low-temperature nitrocarburizing and oxycarbide co-penetrating film according to claim 3, wherein,

the specific steps of putting the part into a nitriding furnace for nitrocarburating are as follows: and placing the part in a nitriding furnace at 440-460 ℃ for nitrocarburizing, wherein the nitrocarburizing time is 120-240min.

5. The method for preparing the alloy steel low-temperature nitrocarburizing and oxycarbide co-penetrating film according to claim 4, which is characterized in that,

the specific steps of placing the parts in an oxidation furnace for salt bath oxidation are as follows: placing the parts in an oxidation furnace at 400-420 ℃ for salt bath oxidation for 20-40min.

6. The method for preparing the alloy steel low-temperature nitrocarburizing and oxycarbide co-penetrating film according to claim 5, which is characterized in that,

the method comprises the specific steps of placing the cleaned part in a preheating furnace for drying and polishing the surface of the part, wherein the specific steps are as follows: and (3) placing the cleaned part in a preheating furnace at 380-400 ℃ for drying, and then polishing the surface of the part by adopting 80-mesh aluminum oxide white corundum.