A multi-element co-penetration method for the surface of high-chromium mechanical parts

Abstract

The present invention provides a multi-element co-permeation method applied to the surface of high-chromium mechanical components, which specifically includes: pre-treatment, nitriding, co-permeation, oxidation, and post-treatment. The multi-element co-permeation method applied to the surface of high-chromium mechanical components forms a Cr2O3 surface film on the surface, thus having a certain corrosion resistance itself. It can achieve the improvement of wear resistance of high-Cr materials at a temperature lower than the temperature that destroys the oxide film and in a relatively short time without reducing the corrosion resistance, greatly improving the comprehensive performance of high-Cr products. The corrosion resistance of high-Cr material products processed by the multi-element co-permeation technology reaches neutral salt spray test (NSS) ≥ 200 hours, and the wear resistance is more than 3 times higher than that before treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of metal processing and relates to a processing technology for the surface of high-chromium mechanical parts. Background Art

[0002] In recent years, due to the good corrosion resistance, excellent toughness and machinability of high Cr materials, the market demand for high Cr material products has continued to expand. At the same time, the market's requirements for product performance are also constantly improving. Although high Cr materials have good corrosion resistance, their wear resistance is poor, and other surface treatment methods are needed to improve their wear resistance.

[0003] The existing salt bath nitriding process, while improving the surface hardness and wear resistance of the product, will destroy its own corrosion resistance, making the comprehensive performance of the product fail to meet the requirements and unable to meet the dual demands of the existing market for corrosion resistance and wear resistance of materials. Therefore, a new technology is needed to process high Cr materials so that it can improve wear resistance without reducing its own corrosion resistance. Summary of the invention

[0004] In order to solve the above-mentioned technical problem of "improving wear resistance without reducing corrosion resistance at the same time", the present invention aims to provide a multi-element co-penetration method for the surface of high-chromium mechanical parts.

[0005] To achieve this purpose, the present invention provides a multi-element co-penetration method applied to the surface of high-chromium mechanical parts, which specifically includes:

[0006] The method consists of the following steps:

[0007] (1) Pretreatment: Check and confirm that there are no problems with the parts, install them with a fixture, clean them, and then put them in a preheating furnace for preheating;

[0008] (2) Nitriding: Place the preheated parts in a nitriding furnace, introduce ammonia gas, and add anhydrous ethanol for nitriding;

[0009] (3) Co-osmosis: Stop adding anhydrous ethanol, and while introducing ammonia gas, add hexamethyldisiloxane urea ethanol solution to perform co-osmosis;

[0010] (4) Oxidation: After the co-penetration is completed, the parts are placed in an oxidation furnace for oxidation;

[0011] (5) Post-processing: After the oxidation is completed, the parts are placed in a clean water tank for quenching and cleaning. After drying, they are placed in the inspection area. After the inspection is completed, they are removed from the card, immersed in anti-rust oil, and packaged.

[0012] Specifically, the preheating furnace temperature is 350°C to 380°C, and the preheating time is 0.5 hour to 2 hours; the nitriding temperature of the nitriding furnace is 480°C to 520°C, the nitriding time is 4 hours to 8 hours, the ammonia introduction rate is 0.6L / min, and the anhydrous ethanol addition rate is 8g / min; the co-infiltration temperature is 480°C to 520°C, the co-infiltration time is 2 hours to 5 hours, and the dripping rate of the ethanol solution of hexamethyldisiloxane is 8g / min; the oxidation temperature in the oxidation furnace is 450°C to 480°C, and the oxidation time is 10 minutes to 30 minutes.

[0013] Specifically, in the ethanol solution of hexamethyldisiloxane, the mass ratio of hexamethyldisiloxane:ethanol is 3-1:1-3; preferably, in the ethanol solution of hexamethyldisiloxane, the mass ratio of hexamethyldisiloxane:ethanol is 1:1.

[0014] Preferably, the multi-element co-penetration method applied to the surface of high-chromium mechanical parts comprises the following steps:

[0015] (1) Pretreatment: Check and confirm that there are no problems with the parts, clamp them with a fixture and clean them. After cleaning, put them in a preheating furnace at 370°C and preheat them for 1.5 hours;

[0016] (2) Nitriding: Place the preheated parts in a nitriding furnace at 500°C, introduce ammonia at a rate of 0.6 L / min, and add anhydrous ethanol at a rate of 8 g / min for nitriding for 6 h.

[0017] (3) Co-osmosis: After stopping the addition of anhydrous ethanol, while continuing to introduce ammonia gas, add hexamethyldisiloxane ethanol solution at a rate of 8 g / min for 4 h.

[0018] (4) Oxidation: After the co-penetration is completed, the parts are placed in an oxidation furnace and oxidized at a temperature of 460°C for 20 minutes;

[0019] (5) Post-processing: After the oxidation is completed, the parts are placed in a clean water tank for quenching and cleaning. After drying, they are placed in the inspection area. After the inspection is completed, they are removed from the card, immersed in special anti-rust oil, and packaged.

[0020] The high-chromium mechanical parts obtained by the method of the present invention have good corrosion resistance, and the wear resistance is more than three times higher than that before treatment.

[0021] Through the above technical solution, the multi-element co-penetration method applied to the surface of high-chromium mechanical parts of the present invention has the following beneficial effects or advantages:

[0022] The present invention enables the steel material mechanical parts with high Cr content to form Cr on the surface. 2 O 3The surface film itself has a certain corrosion resistance, but this oxide film will be destroyed while improving the surface hardness and wear resistance through salt bath nitriding, thereby destroying its own corrosion resistance, making the comprehensive performance of the product fail to meet the requirements and unable to meet the working conditions. The multi-element co-penetration technology provided by the present invention can achieve the improvement of wear resistance of high Cr materials at a temperature lower than the temperature of destroying the oxide film and in a shorter time without reducing corrosion resistance, greatly improving the comprehensive performance of high Cr products.

[0023] The corrosion resistance of high Cr material products processed by multi-element co-penetration technology reaches a neutral salt spray test (NSS) of ≥200 hours, and the wear resistance is increased by more than 3 times compared with before treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of a multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described below in conjunction with embodiments; however, the present invention is not limited to the following embodiments.

[0026] Example 1

[0027] (1) After checking that the parts are correct, clamp them with a fixture and put them into an ultrasonic cleaning machine with a water temperature of 65°C for 15 minutes.

[0028] (2) Place the cleaned parts in a preheating furnace at 370°C and preheat for 1.5 hours.

[0029] (3) The preheated parts were placed in a nitriding furnace at 480°C, ammonia was introduced at a rate of 0.6 L / min, and anhydrous ethanol was added at a rate of 8 g / min for nitriding. The nitriding time was 4 h.

[0030] (4) After the nitridation is completed, stop adding anhydrous ethanol, keep the temperature and the amount of ammonia introduced unchanged, and add an ethanol solution of hexamethyldisiloxane at a rate of 8 g / min for co-infiltration. The co-infiltration time is 2 h; wherein the ethanol solution of hexamethyldisiloxane is obtained by dissolving 15 g of hexamethyldisiloxane in 5 g of ethanol.

[0031] (5) After the co-infiltration is completed, the parts are taken out and placed in an oxidation furnace at 460°C for 10 minutes.

[0032] (6) After the oxidation is completed, the parts are placed in a clean water tank for cleaning, and then inspected. After the inspection is completed, the parts are removed from the card, immersed in anti-rust oil, and packaged to obtain the product.

[0033] Example 2

[0034] (1) After checking that the parts are correct, clamp them with a fixture and put them into an ultrasonic cleaning machine with a water temperature of 65°C for 15 minutes.

[0035] (2) Place the cleaned parts in a preheating furnace at 370°C and preheat for 1.5 hours.

[0036] (3) The preheated parts were placed in a nitriding furnace at 500°C, ammonia was introduced at a rate of 0.6 L / min, and anhydrous ethanol was added at a rate of 8 g / min for nitriding. The nitriding time was 6 h.

[0037] (4) After the nitridation is completed, stop adding anhydrous ethanol, keep the temperature and the amount of ammonia introduced unchanged, and add a mixed solution of hexamethyldisiloxane at a rate of 8 g / min for co-infiltration. The co-infiltration time is 4 hours; wherein the ethanol solution of hexamethyldisiloxane is obtained by dissolving 15 g of hexamethyldisiloxane in 15 g of ethanol.

[0038] (5) After the co-infiltration is completed, the parts are taken out and placed in an oxidation furnace at 460°C for 20 minutes.

[0039] (6) After the oxidation is completed, the parts are placed in a clean water tank for cleaning, and then inspected. After the inspection is completed, the parts are removed from the card, immersed in anti-rust oil, and packaged to obtain the product.

[0040] Example 3

[0041] (1) After checking that the parts are correct, clamp them with a fixture and put them into an ultrasonic cleaning machine with a water temperature of 65°C for 15 minutes.

[0042] (2) Place the cleaned parts in a preheating furnace at 370°C and preheat for 1.5 hours.

[0043] (3) The preheated parts were placed in a nitriding furnace at 520°C, ammonia was introduced at a rate of 0.6 L / min, and anhydrous ethanol was added at a rate of 8 g / min for nitriding. The nitriding time was 8 h.

[0044] (4) After the nitridation is completed, stop adding anhydrous ethanol, keep the temperature and the amount of ammonia introduced unchanged, and add a mixed solution of hexamethyldisiloxane at a rate of 8 g / min for co-infiltration. The co-infiltration time is 5 h; wherein the ethanol solution of hexamethyldisiloxane is obtained by dissolving 5 g of hexamethyldisiloxane in 15 g of ethanol.

[0045] (5) After the co-infiltration is completed, the parts are taken out and placed in an oxidation furnace at 460°C for 30 minutes.

[0046] (6) After the oxidation is completed, the parts are placed in a clean water tank for cleaning, and then inspected. After the inspection is completed, the parts are removed from the card, immersed in anti-rust oil, and packaged to obtain the product.

[0047] Example 4

[0048] The products obtained in Examples 1-3 were compared with commercially available high-chromium accessories (purchased from Hebei Xuxiao) for process effect analysis. The analysis results are shown in Table 1.

[0049] Table 1 Process effect analysis

[0050]

[0051] The products obtained in Examples 1-3 and commercially available high chromium accessories (purchased from Hebei Xuxiao) were tested for salt spray resistance. The results are shown in Table 2.

[0052] Table 2 Salt spray resistance comparison

[0053]

[0054] It can be seen from Table 1 and Table 2 that the hardness of the high chromium mechanical parts produced by the present invention is significantly stronger than that of the commercially available high chromium accessories, and while the hardness is improved, the corrosion resistance of the mechanical parts is not reduced.

[0055] As described above, the present invention can be well implemented. The above embodiments are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various changes and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the present invention.

Claims

1. A multi-element co-penetration method applied to the surface of high-chromium mechanical parts, characterized in that: The method consists of the following steps: (1) Pretreatment: Check and confirm that there are no problems with the parts, install them with a fixture, clean them, and then put them in a preheating furnace for preheating; (2) Nitriding: Place the preheated parts in a nitriding furnace, introduce ammonia gas, and add anhydrous ethanol for nitriding; (3) Co-osmosis: Stop adding anhydrous ethanol, and while introducing ammonia gas, add hexamethyldisiloxane urea ethanol solution to perform co-osmosis; (4) Oxidation: After the co-penetration is completed, the parts are placed in an oxidation furnace for oxidation; (5) Post-processing: After the oxidation is completed, the parts are placed in a clean water tank for quenching and cleaning. After drying, they are placed in the inspection area. After the inspection is completed, they are removed from the card, immersed in anti-rust oil, and packaged.

2. A multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: The temperature of the preheating furnace is 350° C. to 380° C., and the preheating time is 0.5 hour to 2 hours.

3. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: The nitriding temperature of the nitriding furnace is 480° C. to 520° C., the nitriding time is 4 hours to 8 hours, the amount of ammonia introduced is 0.6 L / min, and the amount of anhydrous ethanol added is 8 g / min.

4. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: The co-infiltration temperature is 480° C. to 520° C., the co-infiltration time is 2 hours to 5 hours, and the dripping rate of the hexamethyldisiluzia ethanol solution is 8 g / min.

5. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: In the ethanol solution of hexamethyldisiloxane, the mass ratio of hexamethyldisiloxane to ethanol is 3-1:1-3.

6. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: In the ethanol solution of hexamethyldisiloxane, the mass ratio of hexamethyldisiloxane to ethanol is 1:

1.

7. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: The oxidation temperature in the oxidation furnace is 450° C. to 480° C., and the oxidation time is 10 minutes to 30 minutes.

8. The multi-element co-penetration method applied to the surface of high-chromium mechanical parts according to claim 1, characterized in that: The following steps are involved: (1) Pretreatment: Check and confirm that there are no problems with the parts, clamp them with a fixture and clean them. After cleaning, put them in a preheating furnace at 360°C and preheat them for 1 hour; (2) Nitriding: Place the preheated parts in a nitriding furnace at 500°C, introduce ammonia at a rate of 0.6 L / min, and add anhydrous ethanol at a rate of 8 g / min for nitriding for 6 h. (3) Co-osmosis: After stopping the addition of anhydrous ethanol, while continuing to introduce ammonia gas, add hexamethyldisiloxane ethanol solution at a rate of 8 g / min for 4 h. (4) Oxidation: After the co-penetration is completed, the parts are placed in an oxidation furnace and oxidized at a temperature of 460°C for 20 minutes; (5) Post-processing: After the oxidation is completed, the parts are placed in a clean water tank for quenching and cleaning. After drying, they are placed in the inspection area. After the inspection is completed, they are removed from the card, immersed in special anti-rust oil, and packaged.

9. High chromium mechanical parts prepared by the multi-element co-penetration method according to any one of claims 1 to 8.

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