Galvanized sheet, due to its excellent anti-corrosion properties and high strength, is widely used in various industrial applications. However, it is a challenge to cut and process it accurately. Cutting requires special attention because its surface is hot-dipped galvanized, and this zinc coating not only helps to prevent corrosion, but may also affect the integrity of the zinc layer when cutting. Therefore, when cutting galvanized sheets, proper cutting methods and protective measures are required to ensure the quality of the cut and avoid damage to the zinc layer. In this article, we will introduce the knowledge of galvanized sheet cutting to help you understand the principles, methods and application scenarios of this technology.

1. Preparation before cutting galvanized sheet

(1) Selecting the right cutting tool

Selecting the right cutting tool is crucial for cutting. Common cutting tools include:

Plate shears: the cutting process is fast and neat, but not suitable for thick plates.

Laser cutter or plasma cutter: For situations where high precision cutting is required, especially for thicker plates, a laser or plasma cutter can provide very precise cutting edges.

(2) Cleaning the surface

Although the surface of galvanized sheets has been galvanized, it is still necessary to clean the surface to remove any oil, dirt or other impurities before cutting. A wire brush or brush can be used to clean the cutting area of the galvanized sheet.

(3) Safety Protection

As sparks and metal shavings will be generated during the cutting process, wear appropriate personal protective equipment when operating:

Protective eyewear: to protect eyes from sparks and metal shavings.

Earmuffs: to protect hearing, especially when using angle grinders or band saws, which are noisy.

Protective gloves: to prevent injury from sharp galvanized edges and cutting blades.

Work clothes: Wear fire-resistant and protective work clothes.

2. Cutting steps

The steps for cutting galvanized sheet metal can be briefly summarized in the following three sections:

(1) Marking the cutting line: Use a tape measure and marker to mark the line to be cut on the galvanized sheet metal. Make sure that the marked lines are clear and accurate so that you can follow them during the cutting process.

(2) Make the cut: Cut along the marked lines according to the selected cutting tool. During the cutting process, keep the tool stable and moving at a constant speed to avoid excessive cutting marks or burrs. If you need to adjust the cutting direction or angle, you should try it in the safe area first to ensure that the operation is skillful before the actual cutting.

(3) Check the cutting effect: after the cutting is completed, check whether the cutting surface of the galvanized sheet is flat and smooth. If obvious burrs or unevenness are found, it should be trimmed and processed in time.

3. Common galvanized sheet cutting methods and techniques

(1) mechanical cutting

This is a simple and direct way, usually using professional shears to cut galvanized sheet, shears can quickly cut the sheet into the required size, according to the thickness of the galvanized sheet to adjust the shearer's kerf spacing, and the cutting surface is flat. However, this method is often not high precision, suitable for occasions that do not require high cutting precision.

Cutting process: fix the galvanized sheet on the shear table to ensure that the cutting area is aligned; use the shear to cut, avoid over-exertion, and ensure that the shear is smooth; after cutting, check the cutting edge, and deburr if necessary.

(2) Plasma cutting

uses a high-temperature plasma arc to melt the material, and at the same time uses a high-speed airflow to blow away the molten metal, thus realizing cutting. Plasma cutting is suitable for galvanized sheets with large thickness, and the cutting speed is faster and suitable for mass production. Plasma cutting offers better cut quality and faster speeds, but requires higher operating skills and equipment. Plasma cutting requires the use of appropriate gases (such as air, oxygen or nitrogen) to protect the cutting area, and the current strength is usually 100A to 150A.

(3) Laser Cutting

Precise cutting is achieved by irradiating the surface of galvanized sheets with a high-energy laser beam, which rapidly melts or vaporizes the galvanized sheets, and at the same time blowing the melted or vaporized material out of the cutting slit with an auxiliary gas. Laser cutting has the advantages of high precision, high efficiency and low heat impact, and is suitable for complex cut lines. It is usually used for stainless steel or hot-dip galvanized steel grating that requires fine workmanship, and is an important tool in modern metal processing. Laser cutting machine power is usually 1000W to 3000W, cutting speed of 1-3 meters / minute.

(4) Other cutting technologies

Waterjet cutting utilizes an ultra-high-pressure water stream (sometimes mixed with abrasives) to cut metal, which is a cold cutting process that does not produce thermal deformation. Waterjet cutting can process almost any thickness of galvanized sheet, and environmental pollution-free, but equipment maintenance costs are high. Wire cutting is mainly used for high-precision, complex shape of galvanized sheet parts processing, through the wire discharge corrosion material to achieve cutting. This method is extremely high precision, but slow, suitable for small quantities of high-precision parts production.

4. Processing of galvanized sheet metal after cutting

(1) Cutting Processing

Most cutting methods produce cuts that require some degree of follow-up processing. The burrs produced by mechanical shearing and stamping can be removed by deburring machines or hand filing; the oxidized layer and slag produced by thermal cutting need to be polished and cleaned up; laser and waterjet cuts are cleaner and usually require only simple treatment.

(2) Anti-corrosion treatment

Cutting destroys the zinc layer protection of galvanized sheet, especially the edge of the cut is prone to become a corrosion starting point. For demanding applications, the following anti-corrosion measures can be taken:

Use zinc-based paint or cold galvanizing solution to make up the zinc treatment of the incision; spray antirust primer and top coat, forming a double protection; in the non-appearance of the part can be coated with antirust grease for temporary protection.

(3) Forming process

Many galvanized sheet metal parts in the cut also need further forming process, such as bending, stamping, welding, etc.. These processes need to pay attention to the protection of the galvanized layer to avoid large areas off. Welding should be selected to suit the galvanized plate welding process and materials to reduce the destruction of the zinc layer and the generation of zinc vapor.

5. Precautions for cutting galvanized sheet

When cutting galvanized sheet, the following points need to be noted

(1) The balance of cutting speed and accuracy: different cutting methods have different advantages and disadvantages, you need to choose the appropriate cutting method and parameters according to specific needs.

(2) Protection of the galvanized layer: In the cutting process, we should minimize the damage to the galvanized layer, so as not to affect the corrosion resistance of the galvanized sheet.

6. Application areas of galvanized sheet cutting

(1) Construction industry

Galvanized sheet cutting parts are widely used in the construction field, such as corrugated roof panels, wall panels, rainwater pipes, ventilation ducts and so on. Arbitrary cutting technology can meet the processing needs of various shaped parts in the building, and realize the creative conception of designers.

(2) Home Appliance Manufacturing

The shells and internal structural parts of many home appliances are made of galvanized sheet. Through precision cutting can produce a variety of complex shaped parts to meet the requirements of home appliances on the accuracy and appearance.

(3) Automotive Industry

The automotive manufacturing industry uses a large number of galvanized sheet metal to produce body parts, chassis parts and so on. High-precision cutting technology to ensure the interchangeability of parts and assembly accuracy, while the galvanized layer provides good corrosion resistance.

(4) Furniture Decoration

Modern metal furniture and decorations are often made of galvanized sheet, and a variety of artistic shapes can be realized through arbitrary cutting. After cutting the galvanized sheet after surface treatment (such as spraying, laminating), both beautiful and durable.

(5) industrial equipment

various types of industrial equipment shells, shields, structural components are also widely used galvanized sheet. According to the requirements of the equipment, you can choose a different thickness and cutting process, balancing cost and performance.

7. The development trend of galvanized sheet cutting technology

With the progress of science and technology, galvanized sheet cutting technology is also constantly innovating. Intelligent cutting equipment can monitor the cutting process in real time through sensors, and automatically adjust the parameters to obtain the popular cutting quality; the popularity of CNC technology makes the processing of complex shapes easier; new cutting processes such as ultra-fast laser cutting, composite cutting, etc. continue to emerge, improving processing efficiency and quality.

Environmental requirements also promote the development of cutting technology, reduce energy consumption, reduce noise and pollution emissions become an important direction of equipment improvement. The improvement of automation reduces the labor intensity of workers and improves safety.