What Is Galvanneal Steel Sheet?
Galvanneal is a steel product that starts out as a galvanized sheet. But unlike galvanized metal, it’s heated after the zinc coating is applied in order to anneal it.
This makes it easier to form and paint. It also offers excellent corrosion resistance and ductility. This material is often used in building components like bridges, highway signs and garage doors, as well as electrical systems.
Corrosion Resistance
The zinc-iron alloy layer that forms on the surface of galvannealed steel offers exceptional corrosion resistance. This is particularly beneficial in industries that conduct a lot of welding operations, such as automotive manufacturing and construction. The coating prevents weld spatter and provides an electrically conductive surface, which helps create strong and reliable welds.
Additionally, the matte surface texture of galvannealed steel sheets is galvanized steel coil manufacturers pivotal in facilitating superior paint adhesion. This makes it the perfect choice for applications that require a high-quality, durable finish. This not only enhances aesthetic appeal, but also minimizes maintenance and replacement costs over time.
The fusion of the galvanization and annealing processes results in galvanneal sheet steel that is highly versatile and suitable for various industries. It is often used in applications where both corrosion protection and a painted finish are required, such as the production of parts and panels for cars, appliances, and other consumer goods. Furthermore, it is also well-suited for deep drawing, forming, and high-tensile stress conditions.
Paintability
Galvannealed steel has a matte finish that is much easier for paint to bond to, making it the most paint-friendly form of galvanized steel. The annealing process also makes the zinc coating more absorbent, which helps it hold onto applied paint and prevent flaking or peeling.
The annealing process is important because it relaxes interior stresses in the crystalline structure of ferrous metals. This makes it easier to weld the material without causing cracks or other structural defects. This property is a big selling point for galvanneal because it allows manufacturers to use it in applications that require welding, like manufacturing automotive parts.
In addition, the ductility of galvanneal is useful for industries that require significant forming or bending of the metal. This flexibility allows the material to conform to complex shapes without compromising the protective layer or the structural integrity of the steel underneath.
The metallurgical process of hot-dip galvanizing involves running continuous coils of steel through a bath of molten zinc. The zinc reacts with the surface of the steel, creating an iron-zinc alloy that acts as a barrier to protect against corrosion and promote strength. The resulting material is known as galvannealed steel sheet, and it is used in a variety of applications because of its exceptional properties. Among these are industrial applications, such as manufacturing automotive parts and other machinery, and home appliances like refrigerators, washing machines, and dryers.
Formability
The low ductility of advanced high strength steels (AHSSs) makes it difficult to use them in Durable carbon steel structures that require large amounts of bending. However, galvannealed steel can be easily bent and manipulated into different shapes without suffering damage or cracking. This property, along with its excellent corrosion resistance, make galvanneal steel an ideal choice for applications where the metal will be regularly shaped or curved.
A hot rolled and galvanized steel sheet is subjected to the Fe-Zn alloying process by heating it up at a temperature range of 500 to 600 deg C for a period of time. The alloy layer formed by the process has a tensile strength of around 400 MPa and a weldability superior to that of galvanized steel. The addition of silicon improves the low temperature chipping resistance of the zinc-iron alloy coating.
The galvanneal steel has a matte finish that acts as a primer and can be painted easily. It is also rust resistant and can stand up to manufacturing damages such as scratches, scrapes, and dents. This, along with its comparatively lower cost than galvanized steel, makes it an attractive choice for various applications. It is most commonly used in the production of automobile panels and household appliances, for instance, as well as in electrical systems such as enclosures and junction boxes.
Weight
Galvannealed steel is heavier than standard galvanized because of the annealing process it undergoes. The annealing process is necessary to give the steel a zinc-iron alloy coating. This is an important step because it gives the steel a superior surface for painting and makes it less susceptible to flaking or peeling over time. This also helps the paint adhere better to the metal.
As a result, galvanneal steel is ideal for products that require an aesthetic finish like door frames and garage doors. It also has excellent formability, weldability and galvanic protection, making it a good choice for applications where the metal needs to be bent into a complex shape without damaging it.
Another important advantage of galvanneal steel is its ductility. Because it has a zinc-iron alloy coating, it can be formed into a variety of shapes without damage. This is especially useful for applications that require bending the metal, such as HVAC ductwork or automotive parts.
Stainless Supply offers G90 Galvanneal, which is a type of hot-dip galvanized steel with a minimum of 0.90 ounces of zinc per square foot on both sides of the sheet. This is similar to standard galvanized, but the Galvanneal has a lighter dull gray appearance, and it contains iron that allows the paint to “grip” the metal, which improves its adhesion.
