阅读说明：本技术 一种模具氮化工艺 (Mold nitriding process ) 是由 杨如宏 蒋佳丽 吴露雷 顾剑锋 王博 张幸 杨旭东 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种模具氮化工艺,包括以下步骤：表面清理、预氧化和可控氮化,此模具及模具氮化工艺,本发明的可控渗氮方法,提升表面硬度的同时,调节氮化层深度,提高模具的热疲劳性能,在保证模具表面渗层的高硬度和高热疲劳性能的同时,提高了渗氮层的深度,能够有效阻止热裂纹萌生及扩展,区别于传统的渗氮工艺,预氧化为后续渗氮提供更为便捷扩散通道,保证氮原子渗入,提高硬度的同时抑制Fe-N化合物层。(The invention discloses a mold nitriding process, which comprises the following steps: the surface cleaning, the pre-oxidation and the controllable nitridation, the die and the die nitridation process, the controllable nitridation method of the invention can adjust the depth of a nitrided layer and improve the thermal fatigue performance of the die while improving the surface hardness, can improve the depth of a nitrided layer while ensuring the high hardness and the high thermal fatigue performance of a surface nitrided layer of the die, can effectively prevent the initiation and the expansion of thermal cracks, is different from the traditional nitridation process, provides a more convenient diffusion channel for the subsequent nitridation by the pre-oxidation, ensures the penetration of nitrogen atoms, and inhibits an Fe-N compound layer while improving the hardness.)

1. A mold nitriding process is characterized in that: the method comprises the following steps:

the method comprises the following steps: surface cleaning: removing an oxide layer on the surface of the mold through equipment, and then cleaning;

Step two: the pre-oxidation process comprises the following steps: heating the sample in air to form a thin oxide layer and promote the nitridation process;

Step three: controllable nitridation: the formation of a white layer is inhibited by adjusting technological parameters such as temperature, ammonia decomposition rate, nitriding time and the like, the hardness of the surface layer is improved, and the depth of a nitriding layer is ensured;

the surface cleaning in the first step comprises the following steps:

a: the step comprises a grinding machine for grinding a to-be-ground part, wherein a turnover plate is arranged on the grinding machine, and a grinding output end of the grinding machine grinds the to-be-ground part on the turnover plate;

b: the step comprises a turnover plate, wherein a turnover device is arranged below the turnover plate, and the turnover plate can be adjusted at a certain angle through the turnover device;

c: the step comprises a fine adjustment device, wherein the fine adjustment device is arranged inside the turnover plate, and the turnover plate can be further subjected to angle fine adjustment through the fine adjustment device.

2. the mold nitridation process of claim 1, wherein: the organic solvent is alcohol or acetone, etc.

3. the mold nitridation process of claim 1, wherein: and step two, pre-oxidation heating temperature is 400-500 ℃, and heat preservation time is 2-4 h.

4. The mold nitridation process of claim 1, wherein: and step three, the nitriding temperature can be controlled to be 500-600 ℃, the ammonia decomposition rate is 75-95%, and the nitriding time is 10-25 h.

5. The mold nitridation process of claim 4, wherein: under the condition, the depth of the obtained penetration layer is 100 mu m, and the hardness is 900-1000 Hv.

6. the mold nitridation process of claim 1, wherein: turning device includes first lead screw (21), recess (8) are seted up to the inside of polisher, bearing and recess (8) inner wall connection are passed through at the both ends of first lead screw (21), just arbitrary one end of first lead screw (21) runs through recess (8) lateral wall and is connected with motor (6), threaded connection has first thread bush (9) on first lead screw (21), just it has jack-up pole (10) to articulate on the outer wall of first thread bush (9), the other end of jack-up pole (10) articulates has fine movable plate (25), fine movable plate (25) rotate to be connected on returning face plate (3).

7. the mold nitridation process of claim 1, wherein: the fine setting device includes turning block (23), the one end and little movable plate (25) of turning block (23) are articulated, the other end both sides sliding connection of dwang (23) has slide rail (26), the inside of slide rail (26) fixed and returning face plate (3), the one end that dwang (23) is close to slide rail (26) articulates there is electric telescopic handle (24).

8. The mold nitridation process of claim 7, wherein: t-shaped grooves (11) are formed in the fixed plate (2) and the turnover plate (3), and T-shaped blocks (5) are connected in the T-shaped grooves (11) in a sliding mode.

9. The mold nitridation process of claim 8, wherein: t type piece (5) include second lead screw (12), the both ends of second lead screw (12) are fixed in the inside of T type piece (5) through the bearing, just the top of T type piece (5) is run through to the one end of second lead screw (12), threaded connection has second thread bush (14) on second lead screw (12), the outer wall connection of second thread bush (14) has connecting block (15), and stopper (16) are connected to the other end of connecting block (15), just spout (17) sliding connection that stopper (16) and T type piece (5) lateral wall were seted up.

10. The mold nitridation process of claim 9, wherein: one end of the second screw rod (14) penetrating through the T-shaped block (5) is connected with a polygonal block (18).

Technical Field

The invention relates to the technical field of die-casting molds, in particular to a mold nitriding process.

Background

the die casting mold is an important hot work mold, and about 50% of aluminum alloy products all over the world are completed by a die casting process. In the process of producing aluminum alloy products by die casting, the aluminum alloy products are in a high-temperature and high-pressure environment for a long time, and when the aluminum alloy products are filled, the inner surface of a die expands due to rapid temperature rise to form compressive stress. In contrast, when the mold is opened and cooled by the coolant, the surface metal shrinks due to a rapid drop in temperature, resulting in tensile stress. The tensile stress and the compressive stress are repeatedly and alternately carried out, heat cracks, namely heat fatigue cracks, are formed after the tensile stress and the compressive stress exceed the strength of the material, the die fails after the heat fatigue cracks reach a certain degree, in addition, high-temperature molten metal can also cause the failures in the forms of abrasion, corrosion and the like on the surface of the die, the die needs to be polished and cleaned before the nitriding process, the die needs to be manually disassembled and cleaned after being polished usually, and the die has residues because the die cavity and other depressed areas exist in the center of the die and are directly cleaned on a polishing device, so that the processing efficiency is influenced. To this end, we propose a mold nitridation process.

Disclosure of Invention

The present invention is directed to a mold nitridation process to solve the problems of the background art.

In order to achieve the purpose, the invention provides the following technical scheme: a mold nitriding process comprises the following steps:

the method comprises the following steps: surface cleaning: and removing the oxide layer on the surface of the mold through equipment, and then cleaning.

step two: the pre-oxidation process comprises the following steps: the nitridation process is facilitated by heating the sample in air to form a thin oxide layer.

Step three: controllable nitridation: the formation of a white layer is inhibited by adjusting technological parameters such as temperature, ammonia decomposition rate, nitriding time and the like, the hardness of the surface layer is improved, and the depth of a nitriding layer is ensured.

The surface cleaning in the first step comprises the following steps:

a: the step comprises a grinding machine for grinding the workpiece to be ground, wherein a turnover plate is arranged on the grinding machine, and the grinding output end of the grinding machine grinds the workpiece to be ground on the turnover plate.

b: the step comprises a turnover plate, wherein a turnover device is arranged below the turnover plate, and the turnover plate can be adjusted at a certain angle through the turnover device.

c: the step comprises a fine adjustment device, wherein the fine adjustment device is arranged inside the turnover plate, and the turnover plate can be further subjected to angle fine adjustment through the fine adjustment device.

Preferably, the organic solvent is alcohol or acetone.

Preferably, in the second step, the pre-oxidation heating temperature is 400-500 ℃, and the heat preservation time is 2-4 hours.

Preferably, the nitriding temperature is controlled to be 500-600 ℃, the ammonia decomposition rate is 75-95%, and the nitriding time is 10-25 h.

Preferably, the depth of the penetrated layer is 100 μm under the condition, and the hardness is 900-1000 Hv.

Preferably, turning device includes first lead screw, the inside of polisher is seted up flutedly, bearing and recess inner wall connection are passed through at the both ends of first lead screw, just the arbitrary one end of first lead screw is run through the recess lateral wall and is connected with the motor, threaded connection has first thread bush on the first lead screw, just it has the jack-up pole to articulate on the outer wall of first thread bush, the other end of jack-up pole articulates there is little movable plate, little movable plate rotates to be connected on the returning face plate.

Preferably, micromatic setting includes the turning block, the one end and the fine motion plate of turning block are articulated, the other end both sides sliding connection of dwang has the slide rail, the slide rail is fixed with the inside of returning face plate, the dwang is close to that the one end of slide rail articulates there is electric telescopic handle.

Preferably, the fixed plate and the turnover plate are both provided with T-shaped grooves, and T-shaped blocks are connected in the T-shaped grooves in a sliding mode.

preferably, the T-shaped block comprises a second lead screw, two ends of the second lead screw are fixed inside the T-shaped block through bearings, one end of the second lead screw penetrates through the top of the T-shaped block, a second threaded sleeve is in threaded connection with the second lead screw, the outer wall of the second threaded sleeve is connected with a connecting block, the other end of the connecting block is connected with a limiting block, and the limiting block is in sliding connection with a sliding groove formed in one side wall of the T-shaped block.

preferably, one end of the second screw rod penetrating through the T-shaped block is connected with a polygonal block.

Compared with the prior art, the invention has the beneficial effects that:

1. According to the invention, the turnover plate for placing the grinding piece is turned over at a certain angle through the turning device, and after grinding is finished, the internal scraps can be easily discharged through the turning of the turnover plate, so that the turnover plate can be conveniently cleaned manually, and the whole processing efficiency is improved to a certain extent.

2. The controllable nitriding method provided by the invention can be used for regulating the depth of the nitriding layer and improving the thermal fatigue performance of the die while improving the surface hardness, and can be used for improving the depth of the nitriding layer while ensuring the high hardness and the high thermal fatigue performance of the surface nitriding layer of the die and effectively preventing the initiation and expansion of thermal cracks.

3. The method is different from the traditional nitriding process, and the preoxidation provides a more convenient diffusion channel for subsequent nitriding, so that nitrogen atoms are ensured to permeate, the hardness is improved, and the Fe-N compound layer is inhibited.

Drawings

FIG. 1 is a process flow diagram of the present invention;

FIG. 2 is an overall view of the polishing apparatus;

FIG. 3 is a half-sectional view of the polishing apparatus;

FIG. 4 is an enlarged view of area A in FIG. 3;

FIG. 5 is a structural view of a turnover plate of the polishing device;

FIG. 6 is an enlarged schematic view of region B in FIG. 5;

FIG. 7 is an overall view of a T-block;

FIG. 8 is a half-sectional view of a T-block;

FIG. 9 is a connection diagram of the flipping board and the inching board;

FIG. 10 is a half-sectional view of the flipping board and the inching board;

Fig. 11 is an enlarged view of the area C in fig. 10.

in the figure: 3-turning over the board; 4-a turning device; 5-T-shaped blocks; 6, a motor; 8-a groove; 9-a first threaded sleeve; 10-jacking up the rod; 11-T-shaped groove; 12-a second screw rod; 14-a second threaded sleeve; 15-connecting blocks; 16-a limiting block; 17-a chute; 18-polygonal blocks; 19-a travel switch; 21-a first lead screw; 22-a fine-tuning device; 23-a turning block; 24-an electric telescopic rod; 25-a microplate; 26-sliding rail.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-11, the present invention provides a technical solution: a mold nitriding process comprises the following steps:

the method comprises the following steps: surface cleaning: and removing the oxide layer on the surface of the mold through equipment, and then cleaning.

step two: the pre-oxidation process comprises the following steps: the nitridation process is facilitated by heating the sample in air to form a thin oxide layer.

Step three: controllable nitridation: the formation of a white layer is inhibited by adjusting technological parameters such as temperature, ammonia decomposition rate, nitriding time and the like, the hardness of the surface layer is improved, and the depth of a nitriding layer is ensured.

The surface cleaning in the first step comprises the following steps:

a: the step comprises a grinding machine for grinding the workpiece to be ground, wherein a turnover plate is arranged on the grinding machine, and the grinding output end of the grinding machine grinds the workpiece to be ground on the turnover plate.

b: the step comprises a turnover plate, wherein a turnover device is arranged below the turnover plate, and the turnover plate can be adjusted at a certain angle through the turnover device.

c: the step comprises a fine adjustment device, wherein the fine adjustment device is arranged inside the turnover plate, and the turnover plate can be further subjected to angle fine adjustment through the fine adjustment device.

The organic solvent is alcohol or acetone, etc.

And step two, pre-oxidation heating temperature is 400-500 ℃, and heat preservation time is 2-4 h.

And step three, the nitriding temperature can be controlled to be 500-600 ℃, the ammonia decomposition rate is 75-95%, and the nitriding time is 10-25 h.

And step three, obtaining a penetrated layer with the depth of 100 mu m and the hardness of 900-1000 Hv.