In the world of metallic materials, galvanized steel sheets occupy an important position with their unique properties and wide applications. So, what exactly is galvanized steel sheet and what are its significant differences from other types of steel plates? This article will delve into the definition and characteristics of galvanized steel sheets, and compare them in detail with other steel plates to provide readers with a comprehensive and professional understanding.

1. Definition of galvanized steel sheet

Galvanized steel plate is a protective material that covers the surface of ordinary steel plate with a layer of metallic zinc through hot-dip or electroplating processes. The zinc layer uses the principle of "sacrificial anode" to preferentially oxidize and protect the substrate, significantly extending the service life of the steel plate. For example, in humid coastal environments, ordinary steel corrodes within 5-8 years, while galvanized steel can extend its lifespan to over 30 years and improve its corrosion resistance by 4-6 times through hot-dip galvanizing process (coating ≥ 85 μ m).

2. Process differences from ordinary cold-rolled sheet

Ordinary cold-rolled sheet (SPCC) is formed through cold rolling process, with no protective layer on the surface, and requires painting or rust removal treatment to prevent corrosion. It is prone to rusting in humid environments. Galvanized steel plates are coated with a zinc layer on their surface through hot-dip galvanizing (SGCC) or electro galvanizing (SECC) processes. Hot dip galvanizing immerses steel plates in molten zinc at 450 ℃ to form a metallurgical bonded zinc iron alloy layer with a thickness of 60-300g/m 2 and stronger weather resistance; Electroplated zinc forms a zinc layer (20-50g/m 2) through electrochemical deposition, with a uniform and delicate surface, but weak corrosion resistance.

3. Performance comparison with stainless steel

Stainless steel forms a dense oxide film by adding elements such as chromium and nickel to achieve permanent rust prevention, but the cost is high (more than twice the price of galvanized steel sheets in the same specification), and it is prone to deformation in high temperature environments. Galvanized steel plates use a zinc layer as a sacrificial layer, which only increases the cost by 10% -15%, but reduces the total lifecycle cost by 40% -60%. For example, the automotive industry uses galvanized steel sheets, which can reduce weight by 15% -20% and fuel consumption by 3% -5% under the same strength, while the body will not show structural corrosion within 10 years.

4. Subdivision types and application scenarios

Galvanized steel sheet is divided into hot-dip galvanized sheet (SGCC), electroplated galvanized sheet (SECC), alloyed galvanized sheet, etc. SGCC is applicable to heavy corrosion prevention scenarios such as bridges and workshops. The steel structure of Shanghai center Building adopts this process, which reduces the maintenance cost by 60% in 10 years; SECC is used for home appliance casings and communication devices, and its surface can be treated with fingerprint resistance and sweat corrosion resistance; Alloyed galvanized sheet improves weldability through zinc iron alloying and is commonly used in automotive components. In addition, galvanized steel sheets can be further processed into color coated plates, which can be maintained free for more than 20 years through surface coating and are widely used in the field of green buildings.
Galvanized steel plate, a metal material that combines practicality and economy, is shining brightly in the world of metal with its unique charm. The difference between it and other types of steel plates not only reflects the progress of materials science, but also provides diversified choices for different industries. Looking ahead to the future, with the continuous innovation of technology and the increasing diversification of demand, galvanized steel sheets will continue to be optimized and upgraded, exploring broader application spaces. Let's look forward to galvanized steel sheets shining in more fields and contributing more to the development of the industry!