Details of hard chrome plating (industrial chrome plating)
A hard chrome plating (industrial chrome plating) film is a film with a beautiful bluish silver-white color tone, and because it forms a passivation film in the atmosphere, it is a film that can maintain a beautiful color tone without discoloration.
Chromium plating is roughly divided into decorative and industrial use. According to JIS standards, film hardness of 750 HV or more and film thickness of 2 μm or more are for industrial use.
Chrome plating of 2 μm or more is used for industrial purposes because of its good wear resistance.
① Excellent corrosion resistance
It is not easily corroded by acids other than hydrochloric acid and alkalis, and has excellent corrosion resistance.
② High film hardness
Since the hardness of the hard chrome plating film is as high as HV750 or higher, it has excellent wear resistance compared to other metals.
Plating film performance
Melting point: 1890 ° C
Boiling point: 2200 ° C
Thermal expansion: 6.2 × 10-6deg-1 (20 ℃)
Thermal conductivity: 0.16cal / cm ・ sec ・ deg (20 ℃)
Electrical resistance: 18.9 μΩcm (0 ℃)
Details of hard chrome plating (industrial chrome plating)
Q. Is it possible to treat the base material CAC406 with hard chrome (10 μm)?
Also, is it possible to partially mask?
A. Hard chrome processing is available for CAC406 material (6 types of bronze casting).
It is also possible not to apply plating by partially masking.
Q. Will the hardness decrease significantly if the current density is reduced by chrome plating?
What is the factor that reduces the hardness?
A. The reason why the film hardness decreases is thought to be that the decrease in current density reduces the generation of hydrogen + the amount of plating precipitation decreases and the amount of hydrogen taken into the film decreases.
Q. Is there a black plating that can process the inside of the screw hole?
It is a condition that the plating itself should be applied to the "whole" and that the screw holes also need to be plated.
The screw holes are stopped, not through.
A. If it is black hard chrome plating, the inside of the hole can be processed.
We think that it will be applied, but we would appreciate it if you could actually process it as a prototype and evaluate it.
Q. What is the general process of hard chrome plating?
A. It is a general processing process for hard chrome, but it is the following process.
1. 1. Acceptance inspection (confirmation of appearance, quantity, effective plating surface)
2. 2. Jig selection and production for product holding (creation of auxiliary cathode and auxiliary anode as needed)
3. 3. Additional processing such as buffing and masking
4. Solvent degreasing (alkaline degreasing, solvent degreasing)
5. Hard chrome plating
6. Finish buffing and masking removal
7. Quality confirmation (film thickness measurement, visual inspection, quantity confirmation, etc.)
Q. I would like to apply hard chrome plating to the zinc die-cast (zinc die-cast: ZnDC) material. Is this possible?
A. Hard chrome plating is available for zinc die-cast materials. Please tell us the specified film thickness and the presence or absence of buffing.
Q. We are considering plating for injection molding dies. What kind of plating is recommended?
A. You are considering plating the mold for injection molding, but if hardness is required, hard chrome plating or electroless nickel plating is recommended. Teflon electroless composite plating is recommended when releasability is important.
If you can afford to make a prototype, we would appreciate it if you could evaluate all the films we have proposed.
Q. Is it possible to process hard chrome plating on nickel plating?
A. Processing is possible.
We have a track record of hard chrome plating (50 μm) by applying nickel plating to the titanium material as a base.
Q. I would like to process bronze (gunmetal) with chrome plating. Is this possible?
Also, when another company processed the chrome plating, poor adhesion occurred and it was said that the material was the cause. Is the cause of the poor adhesion the material?
A. Chrome plating on bronze (gunmetal) is available.
Although it is a trouble at another company, of course there are problems caused by the material, but we actually analyze it and pursue the true cause and report it.
There may be a problem with the plating process, so in that case we will continue to tell you how to solve the problem.
Q. I would like to process some of the SUS430 products with hard chrome of 70 μm or more. Is this possible?
A. Partial plating is available by masking.
Depending on the shape, it may be difficult to handle masking, so we would appreciate it if you could send us materials that show the shape, such as drawings.
Q. I am treating cast iron parts with hard chrome, but I am having trouble with the surroundings.
Is there a way to improve it?
A. In the normal process, the surface is too rough, so it seems that the surroundings are getting worse.
It is necessary to improve the pretreatment and adjust it so that it can be processed while ensuring adhesion.
We also offer consulting to plating specialists, so please consider it.
Q. I would like to paint on chrome plating. Is there a way to improve the adhesion?
A. When painting the chrome-plated surface, it is possible to improve the adhesion between the paint film and the chrome plating by immersing it in a high-temperature chromic acid solution. Immerse it in a chromic acid solution and let it air dry without washing before painting.
Q. Hard chrome plating is performed at a current density of 20 to 50A / dm2 and a processing temperature of 50 ° C, but the film hardness is low.
What are the possible causes?
A. It is said that the film hardness is low due to hard chrome plating, so it is possible that cations such as iron and trivalent chromium in the plating solution are increasing.
If the bath temperature and current density are appropriate, check for an increase in impurities.
Q. I am considering using hard chrome plating at 300 ° C. Will it reduce wear resistance?
A. There is no problem with hard chrome plating as the hardness does not decrease up to 450 ° C.
In addition, there is no discoloration up to about 400 ° C even in the air, so you do not have to worry about discoloration.
Q. The roll is hard chrome plated, but rust is generated during use. Is it possible to suppress the generation of rust?
The film thickness is 50 μm, and the usage environment is in a slightly humid environment.
A. Since it is used in a slightly damp environment, it is necessary to perform an evaluation test to see how much rust can be suppressed only by hard chrome plating, but cracks that are treated thicker than the current film thickness. -Apply hard chrome plating with few defects in the plating film such as pinholes.
There are methods such as making multiple layers of plating to enhance the rust prevention effect.
Q. I would like to observe cracks and pinholes in nickel chrome plating with a microscope, etc., but it is difficult to observe, but is there a way to make it easier to check?
A. By cleaning the chrome-plated surface and treating it with copper sulfate plating for about 5 minutes, the copper plating will precipitate on the exposed part of the nickel layer, making observation easier.
Q. The iron material (S45C) is hard chrome plated, but I would like to have it peeled off for additional processing. Is it possible to peel off the current plating film?
A. Hard chrome plating (industrial chrome plating) can be peeled off from iron material (S45C).
When peeling, the plating film is peeled off using a peeling liquid, but care must be taken as the material will be slightly roughened.
Q. Is it possible to reduce the hardness of the hard chrome plating film to prevent the film from cracking due to impact resistance?
A. It is possible to reduce the hardness of the chrome-plated film. As a result, we have been able to suppress the hardness to about 600HV.
It is necessary to evaluate the impact resistance due to the reduced film hardness.
Q. We are considering plating the iron shaft. Which is better at wear resistance when comparing 5 μm hard chrome plating and 25 μm electroless nickel plating?
A. It is necessary to evaluate it after processing it into an actual product, but the treatment of 25 μm-treated electroless nickel plating with heat treatment is due to film curing.
I think that it is effective because it improves wear resistance, but it is good to test because there are various friction conditions such as surface roughness and load of the product, but if it is difficult to evaluate with an actual machine, you can also consider a pseudo test etc. Please feel free to contact us.
Q. I would like to apply surface treatment to the stainless steel material to improve mold releasability, but I would like to avoid processing that changes the dimensions, such as plating processing. Is there any processing that you can propose?
A. It is possible to improve the releasability without changing the dimensions by immersing it in a solution of sodium chromate to form a passivation on the surface of the stainless steel material.
Q. I would like to apply nickel plating, copper plating-free and hard chrome plating to the aluminum material. Is this possible?
A. Hard chrome plating can be applied directly to aluminum materials.
Since there are restrictions on the size etc., we will check whether processing is possible if you send us a drawing or other item that shows the shape and size.
Q. I would like to apply industrial chrome plating to the aluminum material (A5052). Is this possible?
A. It is an industrial chrome plating on aluminum material, but it can be processed directly.
I would like to confirm the size and shape of the product, so if you send me a drawing or image drawing by e-mail, I will confirm it.
Q. Is it possible to peel off the chrome plating that is processed on the titanium alloy Ti-6Al-4V (α-β type)?
A. The chrome plating on the titanium alloy Ti-6Al-4V (α-β type) material can be peeled off.
Q. We are considering hard chrome plating on stainless steel material (SUS304). Is it possible to handle it?
A. Hard chrome plating on stainless steel is possible.
We will make an estimate if you can tell us the presence or absence of buffing before and after plating, film thickness indication, product shape, size, etc.
Q. Is it possible to handle hard chrome (finished 30 μm) treatment for large SS400 materials?
The product size is 1600 x 2800 mm in diameter (800 mm inside diameter). I would like to have a hard chrome plating treatment on the inner diameter. Is this possible?
A. We can handle product size and weight.
Detailed meetings are required before we can actually handle the processing.
Q. I would like to improve the wear resistance by applying hard chrome plating to the copper tungsten material.
Is it possible to treat copper tungsten material with hard chrome of about 5 μm?
A. Good adhesion by applying surface roughening (etching) to the copper tungsten material to improve adhesion.
It is possible to apply hard chrome.
Q. I would like to apply hard chrome plating to zinc die-cast (ZnDC). Is this possible?
A. We have a track record of processing zinc die-casting with hard chrome plating in the past.
It can be processed without any problem.
We would appreciate it if you could send us materials that show the shape of the product.
Q. Is it possible to apply matte hard chrome plating to stainless steel (SUS304)?
A. It is possible to use matte hard chrome plating on stainless steel.
The matting method is matting with shot blast.
Connection Co., Ltd.
Please feel free to contact us for plating, coating, polishing, heat treatment, etc.
Consultations and quotations are free.
4-202-5 Shizugaoka, Fukui City, Fukui Prefecture 910-3635 (Japan)