Processing technology for improving corrosion resistance of iron casting

Abstract

According to the processing technology for improving the corrosion resistance of the iron casting, oil stains on the surface of the iron casting are cleaned away through a detergent, then obvious rust stains are wiped through rough grinding of abrasive paper, the performance of the iron casting is improved through preheating, air cooling and re-preheating, then the surface of the iron casting is smooth through polishing, and the corrosion resistance of the iron casting is improved. And then the surface of the iron casting is galvanized, so that the corrosion resistance of the iron casting is improved, the smooth surface is beneficial to galvanizing, the galvanizing uniformity can be guaranteed, finally, the outer side of a galvanized layer is sprayed with an anti-rust sealing agent again, and the corrosion resistance of the iron casting is further enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of iron casting processing, and in particular relates to a processing technology for improving the anti-corrosion performance of iron castings. Background Art

[0002] Iron castings are objects made of molten iron. As iron castings are increasingly used in production and life, the corrosion resistance of iron castings becomes particularly important to ensure their long-term normal use. Iron castings are widely used in the processing and manufacturing of current mechanical equipment, but their surface corrosion resistance is not good, so they need to be surface treated before they are made into finished products.

[0003] The treatment methods for anti-corrosion of cast iron parts mainly include coating treatment and temporary anti-rust treatment. Coating treatment includes blackening and bluing passivation, electroplating, etc. Among them, electroplating is not effective for cast iron parts, so it is not recommended. Temporary anti-rust treatment includes painting and other methods, which are suitable for situations where there are other processing procedures in the later stage. Summary of the invention

[0004] The invention provides a processing technology for improving the anti-corrosion performance of cast iron parts, aiming to solve the problems raised by the background technology.

[0005] The present invention is achieved by a processing technology for improving the anti-corrosion performance of cast iron parts, comprising the following steps:

[0006] S1: Clean the surface of the cast iron parts. Use detergent to wipe off the remaining oil and dirt on the surface of the cast iron parts, and then use sandpaper to wipe off the rust on the surface of the cast iron parts and set aside;

[0007] S2: Deburring the surface of the cast iron part. The cast iron part obtained in step S1 is placed in a burr grinder for grinding to remove the surface burrs of the cast iron part for later use;

[0008] S3: preheating the cast iron parts, placing the cast iron parts obtained in step S2 into a sealed can, and then raising the temperature in the sealed can to 280-300°C, increasing the pressure in the can to 1.8-2MPa, and maintaining the temperature and pressure for 20-25 minutes before use;

[0009] S4: air cooling and rinsing of the iron castings, cooling the iron castings obtained in step S3 to below 150° C. by air cooling, and then rinsing the surface of the iron castings with clean hot water for later use;

[0010] S5: re-preheating the cast iron parts, putting the cast iron parts obtained in step S4 into the sealed tank again, and then raising the temperature in the sealed tank to 300-350°C, increasing the pressure in the tank to 2-2.2MPa, maintaining the temperature and pressure for 10-15 minutes, and then rapidly cooling and releasing the pressure, cooling and setting aside;

[0011] S6: polishing the cast iron part, placing the cast iron part obtained in step S5 in a polishing machine for surface polishing, and setting it aside after polishing;

[0012] S7: galvanizing the surface of the cast iron part, depositing a layer of zinc on the surface of the cast iron part obtained in step S6 by electrolysis for later use;

[0013] S8: Surface sealing treatment of the cast iron part, spraying a layer of anti-rust sealant on the surface of the cast iron part obtained in step S7.

[0014] Preferably, the detergent used in step S1 is a water-based oil cleaning agent, and a rag is used to wipe off the remaining oil and dirt.

[0015] Preferably, the sandpaper used in step S1 is 500-mesh sandpaper.

[0016] Preferably, the temperature of the clean hot water in step S4 is 70-80°C.

[0017] Preferably, the rapid cooling and pressure relief in step S5 is to reduce the temperature and pressure in the closed tank to normal temperature and pressure within 10 seconds.

[0018] Preferably, in step S7, the surface of the cast iron part is galvanized by hot-dip galvanizing. Hot-dip galvanizing is to immerse the cast iron part in molten zinc at a high temperature to form a zinc coating on the surface of the cast iron part.

[0019] Preferably, the thickness of the anti-rust sealant sprayed in step S8 is 1-2 mm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention uses a detergent to clean the oil stains on the surface of the cast iron part, and then roughly grinds with sandpaper to wipe off obvious rust, and then improves the performance of the cast iron part through preheating, air cooling and re-preheating, and then smoothes the surface of the cast iron part through polishing, and then improves the anti-corrosion performance of the cast iron part by galvanizing the surface of the cast iron part. The smooth surface is conducive to galvanizing and can ensure the uniformity of galvanizing. Finally, the anti-rust sealant is sprayed again on the outer side of the galvanized layer to further enhance the anti-corrosion performance of the cast iron part. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] The components of the embodiments of the invention generally described and shown may be arranged and designed in a variety of different configurations. Therefore, the detailed description of the embodiments of the invention provided below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention.

[0024] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0025] Embodiment 1:

[0026] A processing technology for improving the anti-corrosion performance of cast iron parts comprises the following steps:

[0027] S1: Clean the surface of the cast iron parts. Use detergent to wipe off the remaining oil and dirt on the surface of the cast iron parts, and then use sandpaper to wipe off the rust on the surface of the cast iron parts and set aside;

[0028] S2: Deburring the surface of the cast iron part. The cast iron part obtained in step S1 is placed in a burr grinder for grinding to remove the surface burrs of the cast iron part for later use;

[0029] S3: preheating the cast iron parts, placing the cast iron parts obtained in step S2 into a sealed can, and then raising the temperature in the sealed can to 280°C, increasing the pressure in the can to 1.8MPa, and maintaining the temperature and pressure for 20 minutes before use;

[0030] S4: air cooling and rinsing of the iron castings, cooling the iron castings obtained in step S3 to below 150° C. by air cooling, and then rinsing the surface of the iron castings with clean hot water for later use;

[0031] S5: re-preheating the cast iron parts, putting the cast iron parts obtained in step S4 into the sealed tank again, and then raising the temperature in the sealed tank to 300°C, increasing the pressure in the tank to 2MPa, maintaining the temperature and pressure for 10 minutes, and then rapidly cooling and releasing the pressure, cooling and setting aside;

[0032] S6: polishing the cast iron part, placing the cast iron part obtained in step S5 in a polishing machine for surface polishing, and setting it aside after polishing;

[0033] S7: galvanizing the surface of the cast iron part, depositing a layer of zinc on the surface of the cast iron part obtained in step S6 by electrolysis for later use;

[0034] S8: Surface sealing treatment of the cast iron part, spraying a layer of anti-rust sealant on the surface of the cast iron part obtained in step S7.

[0035] The detergent used in step S1 is a water-based oil cleaning agent, and a rag is used to wipe off the remaining oil and dirt.

[0036] The sandpaper used in step S1 is 500-grit sandpaper.

[0037] The temperature of the clean hot water in step S4 is 70°C.

[0038] The rapid cooling and pressure relief in step S5 is to reduce the temperature and pressure in the closed tank to normal temperature and pressure within 10 seconds.

[0039] In step S7, the surface of the cast iron part is galvanized by hot-dip galvanizing. Hot-dip galvanizing is to immerse the cast iron part in molten zinc at a high temperature to form a zinc coating on the surface of the cast iron part.

[0040] The thickness of the anti-rust sealant sprayed in step S8 is 1 mm.

[0041] Embodiment 2:

[0042] A processing technology for improving the anti-corrosion performance of cast iron parts comprises the following steps:

[0043] S1: Clean the surface of the cast iron parts. Use detergent to wipe off the remaining oil and dirt on the surface of the cast iron parts, and then use sandpaper to wipe off the rust on the surface of the cast iron parts and set aside;

[0044] S2: Deburring the surface of the cast iron part. The cast iron part obtained in step S1 is placed in a burr grinder for grinding to remove the surface burrs of the cast iron part for later use;

[0045] S3: preheating the cast iron parts, placing the cast iron parts obtained in step S2 into a sealed tank, and then raising the temperature in the sealed tank to 290° C., increasing the pressure in the tank to 1.9 MPa, and maintaining the temperature and pressure for 23 minutes before use;

[0046] S4: air cooling and rinsing of the iron castings, cooling the iron castings obtained in step S3 to below 150° C. by air cooling, and then rinsing the surface of the iron castings with clean hot water for later use;

[0047] S5: re-preheating the cast iron parts, putting the cast iron parts obtained in step S4 into the sealed tank again, and then raising the temperature in the sealed tank to 325°C, increasing the pressure in the tank to 2.1MPa, maintaining the temperature and pressure for 13 minutes, and then rapidly cooling and releasing the pressure, cooling and setting aside;

[0048] S6: polishing the cast iron part, placing the cast iron part obtained in step S5 in a polishing machine for surface polishing, and setting it aside after polishing;

[0049] S7: galvanizing the surface of the cast iron part, depositing a layer of zinc on the surface of the cast iron part obtained in step S6 by electrolysis for later use;

[0050] S8: Surface sealing treatment of the cast iron part, spraying a layer of anti-rust sealant on the surface of the cast iron part obtained in step S7.

[0051] The detergent used in step S1 is a water-based oil cleaning agent, and a rag is used to wipe off the remaining oil and dirt.

[0052] The sandpaper used in step S1 is 500-grit sandpaper.

[0053] The temperature of the clean hot water in step S4 is 75°C.

[0054] The rapid cooling and pressure relief in step S5 is to reduce the temperature and pressure in the closed tank to normal temperature and pressure within 10 seconds.

[0055] In step S7, the surface of the cast iron part is galvanized by hot-dip galvanizing. Hot-dip galvanizing is to immerse the cast iron part in molten zinc at a high temperature to form a zinc coating on the surface of the cast iron part.

[0056] The thickness of the anti-rust sealant sprayed in step S8 is 1.5 mm.

[0057] Embodiment 3:

[0058] A processing technology for improving the anti-corrosion performance of cast iron parts comprises the following steps:

[0059] S1: Clean the surface of the cast iron parts. Use detergent to wipe off the remaining oil and dirt on the surface of the cast iron parts, and then use sandpaper to wipe off the rust on the surface of the cast iron parts and set aside;

[0060] S2: Deburring the surface of the cast iron part. The cast iron part obtained in step S1 is placed in a burr grinder for grinding to remove the surface burrs of the cast iron part for later use;

[0061] S3: preheating the cast iron parts, placing the cast iron parts obtained in step S2 into a sealed can, then raising the temperature in the sealed can to 300°C, increasing the pressure in the can to 2MPa, and maintaining the temperature and pressure for 25 minutes before use;

[0062] S4: air cooling and rinsing of the iron castings, cooling the iron castings obtained in step S3 to below 150° C. by air cooling, and then rinsing the surface of the iron castings with clean hot water for later use;

[0063] S5: re-preheating the cast iron parts, putting the cast iron parts obtained in step S4 into the sealed tank again, and then raising the temperature in the sealed tank to 350°C, increasing the pressure in the tank to 2.2MPa, maintaining the temperature and pressure for 15 minutes, and then rapidly cooling and releasing the pressure, cooling and setting aside;

[0064] S6: polishing the cast iron part, placing the cast iron part obtained in step S5 in a polishing machine for surface polishing, and setting it aside after polishing;

[0065] S7: galvanizing the surface of the cast iron part, depositing a layer of zinc on the surface of the cast iron part obtained in step S6 by electrolysis for later use;

[0066] S8: Surface sealing treatment of the cast iron part, spraying a layer of anti-rust sealant on the surface of the cast iron part obtained in step S7.

[0067] The detergent used in step S1 is a water-based oil cleaning agent, and a rag is used to wipe off the remaining oil and dirt.

[0068] The sandpaper used in step S1 is 500-grit sandpaper.

[0069] The temperature of the clean hot water in step S4 is 80°C.

[0070] The rapid cooling and pressure relief in step S5 is to reduce the temperature and pressure in the closed tank to normal temperature and pressure within 10 seconds.

[0071] In step S7, the surface of the cast iron part is galvanized by hot-dip galvanizing. Hot-dip galvanizing is to immerse the cast iron part in molten zinc at a high temperature to form a zinc coating on the surface of the cast iron part.

[0072] The thickness of the anti-rust sealant sprayed in step S8 is 2 mm.

[0073] The cast iron parts made by the processing techniques of Example 1, Example 2 and Example 3 were subjected to neutral salt spray corrosion tests respectively. The experimental results are shown in Table 1.

[0074] time 24 hours 48 hours 72 hours 96 hours Example 1 No corrosion No corrosion Slight corrosion Moderate corrosion Example 2 No corrosion No corrosion Slight corrosion Moderate corrosion Example 3 No corrosion No corrosion No corrosion Slight corrosion

[0075] Among them, the test method of the neutral salt spray corrosion test complies with the requirements of GB / T10125, and the test liquid is prepared in accordance with the relevant provisions of GB / T10125. The evaluation standard is: after the test, it should be evaluated according to the degree of corrosion on the surface of the cast iron parts.

[0076] The evaluation criteria are as follows: No corrosion: There is no obvious corrosion on the surface of the cast iron; Slight corrosion: There are local slight white corrosion spots on the surface of the cast iron; Moderate corrosion: There are local moderate white corrosion spots on the surface of the cast iron, but no rust; Severe corrosion: There are large areas of white corrosion spots on the surface of the cast iron, and rust has already appeared.

[0077] Under comprehensive comparison, the anti-corrosion effect of the cast iron parts under the process of Example 3 is the best.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A processing technology for improving the corrosion resistance of cast iron parts, characterized in that: The steps include: S1: Clean the surface of the cast iron parts. Use detergent to wipe off the remaining oil and dirt on the surface of the cast iron parts, and then use sandpaper to wipe off the rust on the surface of the cast iron parts and set aside; S2: Deburring the surface of the cast iron part. The cast iron part obtained in step S1 is placed in a burr grinder for grinding to remove the surface burrs of the cast iron part for later use; S3: preheating the cast iron parts, placing the cast iron parts obtained in step S2 into a sealed can, and then raising the temperature in the sealed can to 280-300°C, increasing the pressure in the can to 1.8-2MPa, and maintaining the temperature and pressure for 20-25 minutes before use; S4: air cooling and rinsing of the iron castings, cooling the iron castings obtained in step S3 to below 150° C. by air cooling, and then rinsing the surface of the iron castings with clean hot water for later use; S5: re-preheating the cast iron parts, putting the cast iron parts obtained in step S4 into the sealed tank again, and then raising the temperature in the sealed tank to 300-350°C, increasing the pressure in the tank to 2-2.2MPa, maintaining the temperature and pressure for 10-15 minutes, and then rapidly cooling and releasing the pressure, cooling and setting aside; S6: polishing the cast iron part, placing the cast iron part obtained in step S5 in a polishing machine for surface polishing, and setting it aside after polishing; S7: galvanizing the surface of the cast iron part, depositing a layer of zinc on the surface of the cast iron part obtained in step S6 by electrolysis for later use; S8: Surface sealing treatment of the cast iron part, spraying a layer of anti-rust sealant on the surface of the cast iron part obtained in step S7.

2. A processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: The detergent used in step S1 is a water-based oil cleaning agent, and a rag is used to wipe off the remaining oil and dirt.

3. A processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: The sandpaper used in step S1 is 500-mesh sandpaper.

4. A processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: The temperature of the clean hot water in step S4 is 70-80°C.

5. The processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: The rapid cooling and pressure relief in step S5 is to reduce the temperature and pressure in the sealed tank to normal temperature and pressure within 10 seconds.

6. A processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: In step S7, the surface of the cast iron part is galvanized by hot-dip galvanizing. Hot-dip galvanizing is to immerse the cast iron part in molten zinc at a high temperature to form a zinc coating on the surface.

7. The processing technology for improving the anti-corrosion performance of cast iron parts according to claim 1, characterized in that: The thickness of the anti-rust sealant sprayed in step S8 is 1-2 mm.