阅读说明：本技术 一种用于金属冲压模具的表面硬化处理方法 (Surface hardening treatment method for metal stamping die ) 是由 刘飞 于 2020-05-08 设计创作，主要内容包括：本发明揭示了一种用于金属冲压模具的表面硬化处理方法,包括初步检验、前抛光、表面氮化、二次抛光、涂层、后抛光和成品检验步骤,采用PVD涂层工艺在金属模具的表面进行处理,使得金属模具的表面形成硬化涂层。本发明可提高金属冲压模具的表面耐磨性,使其硬度变的更高,大大延伸金属模具的寿命；摩擦系数低,致使它的润滑性好,减小加工受力；使金属模具的抗化学腐蚀能力大大提高；能够提高加工质量,防止产品拉毛、拉伤,提升产品质量,降低成本；减少维护的频率,省去反复卸模、抛光再装模的烦恼,提升效率。(The invention discloses a surface hardening treatment method for a metal stamping die, which comprises the steps of primary inspection, front polishing, surface nitriding, secondary polishing, coating, rear polishing and finished product inspection. The invention can improve the surface wear resistance of the metal stamping die, so that the hardness of the metal stamping die is higher, and the service life of the metal stamping die is greatly prolonged; the friction coefficient is low, so that the lubricating property is good, and the processing stress is reduced; the chemical corrosion resistance of the metal die is greatly improved; the processing quality can be improved, the galling and strain of products can be prevented, the product quality is improved, and the cost is reduced; the frequency of maintenance is reduced, the trouble of repeated mould unloading, polishing and re-mould loading is saved, and the efficiency is improved.)

1. A surface hardening treatment method for a metal stamping die is characterized by comprising the following steps:

s1, preliminary examination

Preliminarily checking whether the metal stamping die required to be treated meets the requirements of surface hardening treatment;

s2, pre-polishing

Polishing the surface of the metal die meeting the requirements of the preliminary inspection, and removing foreign matters and/or impurities adhered to the surface of the metal die;

s3 surface nitriding

Nitriding the surface of the metal die;

s4, secondary polishing

Polishing the metal mould subjected to nitriding treatment for the second time to ensure the smoothness of the surface of the metal mould;

s5 coating

Processing the surface of the metal die by adopting a PVD coating process to form a hardened coating on the surface of the metal die;

s6, post-polishing

Polishing the metal mold after S5 to remove redundant coating materials;

s7, inspection of finished products

And (4) checking whether the hardened metal mold is qualified or not, finishing the hardening treatment when the hardened metal mold is qualified, and returning to S4 and sequentially carrying out the treatments of S4, S5, S6 and S7 when the hardened metal mold is unqualified.

2. The method of claim 1, wherein the types of materials for the metal stamping die include die steel, structural steel containing more than 0.3% carbon, cast iron, and cemented carbide.

3. The method of claim 1, wherein in S5, the hardening coating comprises one or more of TiN, TiC, TiCN, ZrN, CrN, MoS2, TiAlN, TiAlCN, TiN-AlN, CNx, DLC, and ta-C.

4. The method of claim 1, wherein the hardened coating has a thickness of 1 to 6 microns.

5. The method of claim 4, wherein the hardened coating has a thickness of 3 microns.

6. The method of claim 1, wherein the coating step is performed for 2 to 6 hours in S5.

7. The method of claim 1, further comprising S61 between S6 and S7,

and S61, coating a polytetrafluoroethylene coating on the surface of the die hardened coating treated in the S6.

8. The method of claim 7, wherein the polytetrafluoroethylene coating has a thickness of 20 to 40 μm.

9. The method of claim 1, wherein the polytetrafluoroethylene coating has a thickness of 30 microns.

10. The method of claim 1, wherein the step S3 includes the following sub-steps:

s31, deoiling the surface of the metal mold in the S2 by using a gas deoiling method;

s32, placing the metal die processed in the S31 into a nitriding furnace, sealing a furnace cover, heating, and removing air in the furnace before heating to 150 ℃;

s33, keeping the treatment temperature in the nitriding furnace at 480-560 ℃ for 4-10 hours;

s34, rapidly cooling and nitriding furnace and metal mold.

Technical Field

The invention belongs to the technical field of surface treatment of dies, and particularly relates to a surface hardening treatment method for a metal stamping die.

Background

The stamping die is a special process equipment for processing materials (metal or nonmetal) into parts (or semi-finished products) in cold stamping processing, and is called a cold stamping die (commonly called a cold stamping die). Stamping is a press working method in which a die mounted on a press is used to apply pressure to a material at room temperature to cause separation or plastic deformation of the material, thereby obtaining a desired part.

The material for making the stamping die comprises steel, hard alloy, steel bonded hard alloy, zinc-based alloy, low-melting point alloy, aluminum bronze, high polymer material and the like. The material for manufacturing the stamping die is mainly made of steel, and the types of the commonly used die working part materials are as follows: carbon tool steel, low alloy tool steel, high carbon high chromium or medium chromium tool steel, medium carbon alloy steel, high speed steel, base steel, and cemented carbide, steel bonded cemented carbide, and the like.

Although the metal stamping die has certain hardness and wear resistance, after the metal stamping die is used for a long time, the wear resistance and the hardness of the metal stamping die can be influenced, so that the friction coefficient can be increased, the lubricity is poor, the processing stress is increased, the service life of the die is seriously influenced, the quality of a product can be influenced, galling and galling of the product are caused, in addition, the maintenance frequency can be increased, the die is frequently required to be disassembled and polished and then assembled, and the production and processing efficiency is influenced.

Therefore, in view of the above technical problems, it is necessary to provide a surface hardening treatment method for a metal press mold.

Disclosure of Invention

The present invention is directed to a surface hardening treatment method for a metal stamping die to solve the above problems.

In order to achieve the above object, an embodiment of the present invention provides the following technical solutions:

a surface hardening treatment method for a metal stamping die comprises the following steps:

s1, preliminary examination

Preliminarily checking whether the metal stamping die required to be treated meets the requirements of surface hardening treatment;

s2, pre-polishing

Polishing the surface of the metal die meeting the requirements of the preliminary inspection, and removing foreign matters and/or impurities adhered to the surface of the metal die;

s3 surface nitriding

Nitriding the surface of the metal die;

s4, secondary polishing

Polishing the metal mould subjected to nitriding treatment for the second time to ensure the smoothness of the surface of the metal mould;

s5 coating

Processing the surface of the metal die by adopting a PVD coating process to form a hardened coating on the surface of the metal die;

s6, post-polishing

Polishing the metal mold after S5 to remove redundant coating materials;

s7, inspection of finished products

And (4) checking whether the hardened metal mold is qualified or not, finishing the hardening treatment when the hardened metal mold is qualified, and returning to S4 and sequentially carrying out the treatments of S4, S5, S6 and S7 when the hardened metal mold is unqualified.

In one embodiment, the types of materials of the metal stamping die include die steel, structural steel with carbon content greater than 0.3%, cast iron, and cemented carbide.

In one embodiment, in S5, the hardened coating has a composition of one or more of TiN, TiC, TiCN, ZrN, CrN, MoS2, TiAlN, TiAlCN, TiN-AlN, CNx, DLC and ta-C.

In one embodiment, the thickness of the hardened coating is 1 to 6 microns.

In one embodiment, the hardened coating has a thickness of 3 microns.

In one embodiment, in S5, the duration of the coating step is 2 to 6 hours.

In one embodiment, between S6 and S7, S61 is further included,

and S61, coating a polytetrafluoroethylene coating on the surface of the die hardened coating treated in the S6.

In one embodiment, the polytetrafluoroethylene coating has a thickness of 20 to 40 μm.

In one embodiment, the polytetrafluoroethylene coating has a thickness of 30 microns.

In one embodiment, the step S3 includes the following sub-steps:

s31, deoiling the surface of the metal mold in the S2 by using a gas deoiling method;

s32, placing the metal die processed in the S31 into a nitriding furnace, sealing a furnace cover, heating, and removing air in the furnace before heating to 150 ℃;

s33, keeping the treatment temperature in the nitriding furnace at 480-560 ℃ for 4-10 hours;

s34, rapidly cooling and nitriding furnace and metal mold.

Compared with the prior art, the invention has the following advantages:

the invention can improve the surface wear resistance of the metal stamping die, so that the hardness of the metal stamping die is higher, and the service life of the metal stamping die is greatly prolonged; the friction coefficient is low, so that the lubricating property is good, and the processing stress is reduced; the chemical corrosion resistance of the metal die is greatly improved; the processing quality can be improved, the galling and strain of products can be prevented, the product quality is improved, and the cost is reduced; the frequency of maintenance is reduced, the trouble of repeated mould unloading, polishing and re-mould loading is saved, and the efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a case hardening treatment method for a metal stamping die according to an embodiment of the present invention;

fig. 2 is a data diagram of an experiment of using effect of a surface hardening treatment method for a metal stamping die according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to embodiments shown in the drawings. The embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to the embodiments are included in the scope of the present invention.