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Cold galvanizing: what is it and what are the applications?

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Cold galvanizing, or zinc-rich paint, is used to protect metals against corrosion and oxidation, and has gained popularity due to its effectiveness and ease of use. Unlike other types of zinc plating it is really a painting process, used to apply a zinc-rich paint made with synthetic resins.

In this article, we will explore what cold galvanizing is in more detail and how it works, highlighting its advantages and applications in modern industry.

What is cold galvanizing?

Cold galvanizing is a coating technique for metals involving the application of a layer of zinc to the surface of the metal, usually by dipping, spraying or using a brush. This coating forms a protective barrier against corrosion and oxidation, extending the useful life of metal and preserving its aesthetic qualities.

Cold galvanising involves the application of zinc salts at room temperature or slightly above. It is a process of electrolysis that enables the zinc to create a resistant and durable layer on the component coated.

Unlike hot-dip galvanizing, which uses high temperatures, cold galvanizing is a more delicate process that does not require the use of flames or special ovens.

How does cold galvanizing work?

The process of cold galvanizing has four main stages:

  1. Surface pre-treatment: before applying the layer of zinc, the surface of the metal is prepared using a pretreatment process that may include cleaning, removal of mill scale (the layer of oxide that forms on the surface of steel products during hot working), degreasing of the component to be treated, removal of any contaminants and dusting of the surface.
  2. Application of zinc layer: application to the surface of the metal is carried out using various techniques, including dipping, spraying or using a brush. This layer acts as an effective barrier against corrosion and oxidation.
  3. Deposition process: deposition of the coating that acts as a protective film occurs through electrolysis (electrodeposition of the zinc on the surface via galvanic currents, enabling completion of galvanizing process without heating the metal). This procedure enables application of the protective layer event on products with thin parts without altering their specifications and on elements with small holes, avoiding blocking them up.
  4. Drying and hardening: following application of the layer of zinc, the coating is dried and hardened at room temperature or with the use of special equipment, depending on the type of product and the specific characteristics of the application.
  5. Quality control: once the process is completed, the coating undergoes quality control to guarantee compliance with required standards and to ensure its durability.

Benefits of cold galvanizing

Some of the many benefits of cold galvanizing are listed below.

  • Extraordinary resistance to corrosive agents: the layer of zinc provides exceptional protection against corrosive agents, making galvanized metals suitable for extremely corrosive environments.
  • Protection against galvanic corrosion: zinc also provides effective protection against galvanic corrosion, extending the useful life of the metal substrate and reducing the risk of damage caused by electrochemical reactions between different metals.
  • Environmental compatibility: cold galvanizing is considered an environmentally friendly way to protect metals, because it does not produce harmful emissions during processing and can be easily recycled at the end of its life cycle.
  • Versatility and durability: cold-galvanised products are recognised for their versatility and durability, providing effective resistance against wear and abrasion. Cold galvanizing can be used on a wide range of metals, including steel, iron, aluminium and copper alloys, and is therefore suitable for many different industrial applications.
  • Ease of application: compared to other methods used to protect metals, cold galvanizing has a relatively simple application process, requiring basic equipment and limited energy resources.
  • Cost effective: compared to other techniques used to protect metals, cold galvanizing is highly cost effective, guaranteeing high-quality protection at an accessible price.
  • Various applications: cold galvanizing is extremely versatile and can be used in a wide range of different fields, including the automotive, construction, maritime and industrial sectors.

Applications of col galvanizing

With its many different applications and proven effectiveness, cold galvanizing continues to be a popular choice for the protection and preservation of metals.

Today, it is used in many different industrial sectors, including: construction, where it is used to protect metal structures exposed to weathering and humidity, the automotive industry, where it is applied to components to prevent corrosion and extend the useful life of vehicles, and the electronics sector, where it is used to coat electronic components to protect them from corrosion and improve conductivity.