How many types of galvanized steel are there?

Carbon There is more than one way to classify galvanized steel. I will not go into detail about galvanized steel. This article mainly talks about the types of galvanized steel.

It can be classified differently according to its production method, processing method, material composition, and performance characteristics.

Classification by production method

Although the galvanized sheets we see have almost the same surface and are smooth, bright, and durable, there are many processing methods for them. According to the process, they are divided into the following 4 categories.

(2)Alloy galvanized steel sheet

It is also hot-dip galvanized, but the difference is that it is immediately heated to 500℃ after leaving the zinc tank to form a zinc-iron alloy film. Therefore, its coating adhesion and weldability are strong.

Classification by coating composition

• Pure zinc coating: more than 99% pure zinc (Zn), medium (15-25 years) corrosion resistance, such as Z120, Z275 are pure zinc coating.
• Aluminum-zinc alloy: coating composition 55% aluminum + 43.4% zinc + 1.6% silicon, such as AZ150, extremely strong (30-50 years) corrosion resistance, can be used as color-coated substrates and roofs.
• Zinc-aluminum-magnesium: coating composition Zn + 5-11% Al + 2-3% Mg, has excellent self-repairing properties, super long (40-60 years) life, can be used for high-end buildings and marine engineering.
• Zinc-nickel alloy: coating Zn + 10-15% Ni, high chemical corrosion resistance, belongs to special anti-corrosion, used in military industry and petrochemical equipment.

Classification by substrate type

Substrates with different processes

• Cold-rolled substrate: cold-rolled to 0.3-3.0mm, smooth surface (Ra≤0.8μm), strong coating adhesion, suitable for color coating (PPGI).
• Hot-rolled pickled substrate: hot-rolled plate pickled to remove oxide scale, low cost, used for thick-gauge structural parts (such as steel beams).
• Black annealed substrate: annealed after cold rolling, dark gray surface, improved stamping performance, mostly used for electrogalvanizing.

Low-carbon substrate for galvanizing

• DX51D: specially designed for hot-dip galvanizing, silicon content ≤0.05% (to prevent excessive growth of zinc layer).
• SPCC: SPCC-SD, cold-rolled low-carbon steel: smooth surface, high precision, suitable for parts with high surface quality requirements (such as home appliance panels) after galvanizing.
• SGCC: Japanese galvanized substrate, divided into ordinary grade (SGCC) and deep drawing grade (SGCD).
• DC01 low-carbon steel: excellent stamping performance, suitable for complex formed parts (such as automotive accessories) after galvanizing.
• CS Type B: American galvanized substrate standard, carbon ≤ 0.10% + manganese ≤ 0.60% (balanced strength and coating adhesion).
• Q195 low carbon steel: low carbon content, good plasticity, easy processing and forming, suitable for galvanized products with low strength requirements.
• Q235 low carbon steel: balanced comprehensive performance, moderate strength, wide application, often used in galvanized scenes such as construction and structural parts.
• St01Z low carbon steel (European standard): low carbon content combined with galvanizing process, both corrosion resistance and processing adaptability, commonly used in machinery manufacturing.

China Carbon Structural Steel Grades

• Q195: Yield strength ≥195MPa, good plasticity, used for thin plates, steel wires, galvanized substrates, etc.
• Q215: Yield strength ≥215MPa, slightly higher strength than Q195, used for tie rods, hooks, etc.
• Q235: Yield strength ≥235MPa, the most widely used, divided into A/B/C/D grades (impact toughness increasing), used for building structures, mechanical parts, galvanized products, etc.
• Q275: Yield strength ≥275MPa, high strength, used for sprockets, shafts, light rails, etc.
• Q345: The old standard was classified as carbon structural steel, now it is low-alloy high-strength structural steel, GB/T 1591-2018.

Classification by use

(1) Industrial steel

Construction steel can usually be divided into steel for steel structures and steel for reinforced concrete structures. Steel for steel structures mainly includes ordinary carbon structural steel and low alloy structural steel. Varieties include section steel, steel pipe, and steel bar. Section steel includes angle steel, I-beam, and channel steel.

(2) Decorative steel

Galvanized steel generally used for decoration, handicrafts, and sculptures is mostly made of galvanized wire mesh, galvanized iron wire, galvanized grille, and galvanized perforated mesh.

Because these scenes generally do not involve load-bearing, huge impact, stretching and torsion, high heat and humidity, etc., the most commonly used process is electro-galvanizing, which is more economical.

(3) Agriculture, roads, vehicles, boats, and electricity

These fields mostly require outdoor galvanized steel, especially in the field of vehicles and ships, which may wade in the water.

Therefore, a hot-dip galvanizing process is required, and the coating thickness is selected according to the environment. It will not fade even if it is washed by wind, snow, and rain.

Surface spangle classification

In addition to the above classification methods, galvanized steel sheets can also be classified according to the quality of the zinc layer (such as the size of the zinc flower and the thickness of the zinc layer), and specific performance requirements (such as fingerprint resistance, corrosion resistance, processability, etc.).

Summary

When you choose galvanized steel, if you don’t have rich professional knowledge, it is best to consult the steel factory staff. China’s Wanzhi Steel is China’s gold medal manufacturer.

In addition to providing you with guidance and suggestions, it also provides wholesale prices. This is our hot-selling galvanized steel plate, galvanized steel coil, and galvanized steel strip. In addition, steel bars, steel pipes, and rebars are also our hot-selling products~

Even if you don’t know which steel to choose and how thick the zinc layer is, please don’t worry. I believe our expertise will solve your problems. We aim to serve every customer wholeheartedly. Your satisfaction is the greatest recognition for us. Welcome to contact us.