Process Of Hard Chrome Plating

Learn The Art And Science Of The Hard Chrome Plating Process.

Hard chrome plating, commonly known as industrial chrome plating, is a standard surface treatment process used in industries to enhance metal material, especially in wear and tear conditions. This process improves the corrosion resistance and increases the overall durability of the component.

Hard chrome-plated rods can vary in thickness and size depending on the specific requirements of the machinery. The average thickness of a hard chrome-plated rod ranges from 2 to 250µm. There are several hard chrome-plated rods, including micro-porous chromium, porous chromium, micro-cracked chromium, and crack-free chromium.

Used in industrial components of machines from aerospace, hydraulic, automotive, and other pieces of machinery, hard chrome plating is a characteristic feature that offers exceptional quality products. Now you may wonder what exactly is the hard chrome plating process and how hard chrome plated rods produced.

The Hard Chrome Plating Process:

A hard chrome plating process generally involves several steps that use chemicals and other chemical procedures that result in the plating. Here is a detailed understanding of this process:

Step 1: Surface Preparation

• The hard chrome plating process begins with preparing the metal surface by cleaning it thoroughly and purifying the components.
• This process ensures that the metal is free of any rust, impurities, oil, contaminants, or existing coatings that can hinder the result.
• Surface preparation is generally done through chemical cleaning, sandblasting, etc.

Step 2: Masking (if needed)

• After surface preparation, the metal piece is moved for masking if needed.
• This process includes covering metal component areas that do not require hard chrome plating.
• The masking process is achieved through particular materials that are only used for this process, including plastic tape, metal tape, or wax. By doing so, the metal component is kept safe from the process.

Step 3: Electroplating Bath Setup

• The next step of this process is preparing a bath for electroplating. The bath is usually a chromic acid solution that is used in the electroplating process.
• The metal component is submerged or soaked in an electroplating tank filled with electrolyte solutions that mostly include hexavalent chromium ions Cr6+.
• A hexavalent chromium bath can include a different electroplating process, including an activation bath, chromium bath, rinse, and second rinse. However, this process is seldom used due to its lower efficiency in plating the metal rod.
• The solution also includes other chemicals like sulfuric acid, which is used in the electroplating process.

Step 4: Electroplating

• Electroplating is the process in which the metal component that needs to be plated is connected to the cathode, which is the negative terminal, and the substance you want it to be plated with is placed in the anode i.e. positive terminal.
• The substances used are usually made of lead or any other insoluble lead alloys.
• When current is passed through the tank filled with solution, it causes the chromium ions to move and settle on the metal surface.

Step 5: Build-Up Layer

• Now that the process of electroplating is started, it continues to follow the procedure until the metal component achieves the desired thickness.
• This process is called building up the layer. It can take several hours or more to complete and finish the hard chrome plating of the metal surface.
• Building up layer is a crucial process because it crafts the final and overall characteristics of hard chrome-plated metal.

Step 6: Post-plating Treatments

• Having completed the layer-building process, the next is post-plating treatment. This process includes various treatments that include passivation, de-oxidation, and rinsing.
• The overall goal of treatment is to improve the metal component’s resistance feature and appearance.
• This step is crucial for machine components that would undergo harsh environmental conditions.

Step 7: Final Inspection

• After the chemical procedures, the quality inspector puts the metal component through a quality check.
• This process ensures that the metal has achieved the desired quality standards after hard chrome plating.
• The quality check generally includes the inspection of surface finish, adhesion, thickness, and any other custom requirements that are added to the metal component.

Step 8: Polishing And Finishing

• This step in a hard chrome plating process is optional as it is often used for decorative applications.
• The polishing and finishing steps aim to achieve a smooth and highly reflective hard chrome-plated surface.
• It further provides a better aesthetic appeal for your product and reduces friction on the metal surface. It is also a great way to achieve dimensional accuracy after the hard chrome plating process.

After the hard chrome plating process, the metal piece undergoes a final inspection process that looks at overall quality and thickness after polishing. The inspection ensures that the metal piece is uniform and ready to ship to the customer. This process can differ depending on the hard chrome plated rod manufacturer’s regulations or needs.

Looking For A Hard Chrome Plate Supplier?

At Bhansali Techno Components, we use an alternative approach that is not environmentally hazardous but produces a fine-quality hard chrome plated rod. The hard chrome plating process is a necessary step for applications like hydraulic piston rods, engine components, and industrial pieces of machinery. Although this process enhances the quality of the metal, it contributes to many environmentally hazardous wastes.

Therefore, companies have opted for alternative processes like electroless nickel plating. As hard chrome-plated rods suppliers, we also provide customized hard chrome-plated rods designed and manufactured according to your specific needs.