Piston Rod Chrome-plating Solution and Chrome Plating Method (Horizontal and Conventional) Affect the Lifespan of the Shaft

Piston rod chrome plating is a surface coating process that involves the deposition of a layer of chromium on a metal substrate; typically steel, to provide protection against corrosion and wear. The chrome plating process involves several steps, including surface preparation, electroplating, and post-treatment.

The applications of chrome plating include hydraulic cylinders, piston rings, thread guides, mold surfaces, gun bores, and other industrial components subjected to high wear and corrosion. Piston rod chrome plating is especially important in hydraulic cylinders because it provides a hard, durable surface that resists wear and corrosion, reducing the risk of failure and increasing component lifespan. The coating also provides a low-friction surface that reduces energy consumption and increases operating efficiency.

What are the different types of chrome plating methods used?

This section will explore the various types of chrome plating methods used and how they differ.

• Conventional type

The conventional type of chrome plating solution involves using a vertical plating barrel. This barrel is filled with the plating solution, which typically contains various chemicals and metals. The piston rod to be plated is inserted into the barrel vertically and then rotated so that the entire piston rod surface is exposed to the plating solution.

The plating solution uses an electrical current to deposit the desired metal onto the surface of the shaft. This process is known as electrode position, and it involves the use of metal ions in the plating solution that are attracted to the negatively charged surface of the piston rod. As the ions come into contact with the surface, they react with it to form a thin layer of metal coating.

The plating solution typically contains various chemicals that help control the deposition process and ensure a uniform coating across the shaft surface. The thickness of the chrome layer is carefully controlled to ensure proper lubrication and prevent cracking or flaking. These chemicals may include additives that improve the adhesion of the plating to the surface of the piston rod, as well as inhibitors that prevent unwanted reactions from taking place. This type of chrome-plating is commonly used in hydraulic cylinders and other industrial applications.

• Horizontal plating

The process involves placing the piston rod horizontally on a rotating fixture, which is then submerged in a chrome plating solution that contains metal ions. An electric current is passed through the solution, causing the metal ions to bond to the surface of the piston rod. The metal ions are attracted to the surface of the piston rod due to the opposite charges between the metal ions and the shaft.

The chrome plating solution is constantly agitated during the process, which ensures that the metal ions are evenly distributed across the surface of the piston rod. This results in a uniform and consistent layer of metal on the shaft.

Horizontal plating is a more advanced process controlled by a computer and automatic robot arm, resulting in a homogeneous chrome layer with good rust and corrosion resistance. The surface is smoother with less chance of micro-holes.

What are the different types of tests used for checking the piston rod chrome-plating?

The corrosion resistance can be tested using NSS and CASS. The international standard for NSS is 72 hours, but Golden Asia can achieve up to 500 hours. Golden Asia CASS can withstand 64 hours and has micro-cracks that improve rust resistance, with 1000-2000 cracks per centimeter.

The ATOTECH Quality report contains information on the chrome plating's thickness, adhesion, and corrosion resistance, which are crucial factors in determining the quality of the chrome plating. For instance, the report may indicate that the chrome plating has a thickness of 25 microns, which is within the recommended range for the piston rod's application.

The external salt spray test is a critical component of the report, as it simulates harsh environmental conditions that the piston rod may encounter in real-world applications. The test involves exposing the plated piston rod to a salt spray mist for a specified period and evaluating its corrosion resistance. The report may provide statistics on the duration of the salt spray test, such as 1000 hours, and the severity of the corrosion, such as a maximum of 3% corrosion.

Conclusion

The method of electroplating used for piston rod chrome plating has a significant impact on the lifespan of the piston rod. Traditional electroplating, while not limited by size and capable of plating larger or customized piston rods, is more susceptible to human influence and requires highly trained staff to ensure consistent quality. Golden Asia is equipped with both conventional type and horizontal chrome plating machine. At Golden Asia, all staff has more than 10 years of experience in the electroplating process, ensuring reliable and high-quality plating.