CN113416918A

CN113416918A - Nitrocarburizing process for extremely-thin parts

Info

Publication number: CN113416918A
Application number: CN202110593176.2A
Authority: CN
Inventors: 王建才
Original assignee: Kunshan Sunmin Drilube Electronic Material Technology Co ltd
Current assignee: Kunshan Sunmin Drilube Electronic Material Technology Co ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2021-09-21

Abstract

The invention discloses a nitrocarburizing process for an extremely thin part, which comprises the following steps of S1: s2, cleaning: removing surface grease by alkaline cleaning; s3, preheating: keeping the temperature at 350 deg.C for 30 min; s4, performing nitrocarburizing in salt bath at 580 ℃ for 60 min; obtaining a compound layer of epsilon-Fe 2-3N on the surface, wherein the surface hardness reaches 450-650 HV; s5, cooling by water cooling; s6, post-cleaning; s7, carrying out post-treatment by vibration grinding; removing dust and dirt generated on the surface of the product in the nitriding process to expose a bright, homogeneous and clean surface, and removing punched burrs; s8, rust prevention: and (5) protecting the product. The salt bath nitrocarburizing process of the invention replaces the application of a superficial carburizing quenching or nitrocarburizing process, and solves the problem of heat treatment deformation while meeting the performance requirements.

Description

Nitrocarburizing process for extremely-thin parts

Technical Field

The invention relates to the field of heat treatment, in particular to a nitrocarburizing process for an extremely thin part.

Background

In the electric switch, many metal components are stamped and formed by low-carbon cold-rolled steel plates, and the processing cost is relatively low. Although the low-carbon cold-rolled steel sheet is easy to form, the low-carbon cold-rolled steel sheet has low strength, is not wear-resistant and corrosion-resistant, and therefore corresponding heat treatment and surface treatment are usually required to achieve the final service performance;

the common heat treatment is carburizing or carbonitriding, and the treatment temperature is usually above 850 ℃, so for a low-carbon cold-rolled steel plate with complicated switch and extremely thin plate thickness (the thickness is usually less than 1.0mm), the heat treatment difficulty is correspondingly high, the deformation ratio is high, and much labor is needed for straightening after the heat treatment. At the same time, the parts of very thin parts can only allow a very shallow carburized hardened layer, otherwise the material will be significantly brittle due to the penetration of the material to a too deep depth (e.g., infiltration or near infiltration), which makes the heat treatment control very difficult and the rejection rate is also very high.

Disclosure of Invention

The invention aims to provide a nitrocarburizing process for extremely thin parts.

The invention realizes the purpose through the following technical scheme: a nitrocarburizing process for an extremely thin part comprises the following steps:

s1, charging:

s2, cleaning: removing surface grease by alkaline cleaning;

s3, preheating: keeping the temperature at 350 deg.C for 30 min;

s4, performing nitrocarburizing in salt bath at 580 ℃ for 60 min; obtaining a compound layer of epsilon-Fe 2-3N on the surface, wherein the surface hardness reaches 450-650 HV;

s5, cooling by water cooling;

s6, post-cleaning;

s7, carrying out post-treatment by vibration grinding; removing dust and dirt generated on the surface of the product in the nitriding process to expose a bright, homogeneous and clean surface, and removing punched burrs;

s8, rust prevention: and (5) protecting the product.

Further, the S1 combines the products with a heat treatment tool to make the products spaced apart.

Further, the step S6 is to wash with flowing water to remove residual salt traces on the surface of the product.

Further, the thickness of the compound layer of S4 epsilon-Fe 2-3N is about 10 μm.

Further, the S4 reaches a diffusion layer with a depth of about 0.2-0.3 mm.

Compared with the prior art, the nitrocarburizing process for the extremely thin part has the beneficial effects that: the salt bath nitrocarburizing process replaces the application of a superficial carburizing quenching or nitrocarburizing process, and solves the problem of heat treatment deformation while meeting the performance requirements.

Drawings

FIG. 1 shows a compound layer obtained by nitrocarburizing an SPCC salt bath, the thickness of which is 12 to 14 μm.

Detailed Description

A nitrocarburizing process for an extremely thin part comprises the following steps:

s1, charging: the products are combined with the heat treatment tool, so that the products are spaced and not mutually extruded, extrusion deformation in the heat treatment process can be prevented, and uniform infiltration layers can be obtained in the heat treatment process;

s2, cleaning: removing surface grease by alkaline cleaning;

s3, preheating, wherein the temperature is 350 ℃, and keeping for 30 min; drying water, forming an oxide film on the surface, and having a certain permeation promoting effect in the nitriding process; meanwhile, in order to reduce the thermal stress of salt bath heating and reduce thermal shock deformation;

s4, performing nitrocarburizing in salt bath at 580 ℃ for 60 min; a compound layer of epsilon-Fe 2-3N with the thickness of about 10 mu m is obtained on the surface, the surface hardness reaches 450-650 HV, and meanwhile, a diffusion layer with the depth of about 0.2-0.3 mm is obtained;

s5, cooling by water cooling: the rapid cooling is carried out, so that nitrogen in the diffusion layer is dissolved in the alpha-Fe to play a role in solid solution strengthening, and the strength and the fatigue resistance of the material can be improved;

s6, post-cleaning: cleaning with flowing water to remove residual salt traces on the surface of the product;

s7, post-treatment by vibration grinding: the dust and dirt generated on the surface of the product in the nitriding process are removed through vibration grinding, the bright, homogeneous and clean surface is exposed, and simultaneously the punched burrs can be removed, so that the service performance of the product is improved;

s8, rust prevention: and (5) protecting the product.

The salt bath nitrocarburizing technology is adopted in the technology, a compound layer of epsilon-Fe 2-3N with the thickness of about 10 mu m is obtained on the surface, referring to figure 1, the surface hardness reaches 450-650 HV, and a diffusion layer with the depth of about 0.2-0.3 mm can be achieved;

the invention has the following advantages:

1) by applying the method, the heat-treated product can be free of a correction process, and the yield can reach 99.9%;

2) the complex performance after the nitrocarburizing of the salt bath is as follows: the hardness, the wear resistance and the corrosion resistance are improved, so that the product is free from surface treatment such as electroplating and other procedures after heat treatment, and the processing cost of the product is greatly reduced;

3) the product processed by the process has extremely low brittleness risk.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics 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. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The nitrocarburizing process for the extremely thin part is characterized by comprising the following steps of:

s1, charging:

s2, cleaning: removing surface grease by alkaline cleaning;

s3, preheating: keeping the temperature at 350 deg.C for 30 min;

s5, cooling by water cooling;

s6, post-cleaning;

s8, rust prevention: and (5) protecting the product.

2. The nitrocarburizing process for an extremely thin part according to claim 1, characterized in that: and S1, combining the products with a heat treatment tool to enable the products to have intervals.

3. The nitrocarburizing process for an extremely thin part according to claim 1, characterized in that: the S6 adopts flowing water to wash and remove residual salt stains on the surface of the product.

4. The nitrocarburizing process for an extremely thin part according to claim 1, characterized in that: the thickness of the compound layer of S4 epsilon-Fe 2-3N is about 10 mu m.

5. The nitrocarburizing process for an extremely thin part according to claim 4, wherein: the S4 reaches a diffusion layer with a depth of about 0.2-0.3 mm.