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1. Your company name, individual name, telephone number, email
2. Welding application: material type, thickness, etc
3. Input voltage
4. Current and time used for welding
5. Welding beat
6. Special functional requirements? For example: bus communication, adaptive functions, etc. (welding applications, input power supply voltage, secondary current output requirements, air cooling or water cooling, and adaptive, communication and other configuration requirements)

I. Spot Welding of Low Carbon Steel

Low carbon steel exhibits excellent spot welding characteristics. Due to its low carbon content [w(C) < 0.25%], it has moderate electrical resistance and thermal conductivity, requiring lower welding current. With a wide plastic temperature range, it is easy to achieve the desired plastic deformation without the need for excessive electrode force. Low carbon steel has low carbon and other alloy element content, minimizing the formation of high melting point oxides, generally avoiding quenching structures or inclusions. It also has a narrow crystallization temperature range, low high-temperature strength, and a small coefficient of thermal expansion, reducing the tendency for weld cracking.

Therefore, spot welding of low carbon steel has a large welding window, and complex welding processes are not required. Adjusting various welding parameters within a wide range easily yields satisfactory welding quality.

II. Spot Welding of Galvanized Steel Sheets

Galvanized steel sheets can be categorized into electro-galvanized steel sheets and hot-dip galvanized steel sheets, with the former having a thinner coating than the latter. The melting point of the coating metal is usually lower than that of the steel sheet. When heated, the coating metal that melts first increases the contact area between the two sheets, reducing the current density. Therefore, the welding current for welding galvanized steel sheets is about 30% to 50% higher than that for low carbon steel without zinc coating. The thicker and more uneven the coating, the higher the required current. Welding time should also be increased by 25% to 50% to ensure the molten zinc layer is uniformly extruded around the welding area, preserving its original protective function. Due to the higher welding current and longer welding time, increased electrode force is necessary to avoid splashing, and it also helps to extrude the melted coating around the welding area. Generally, the electrode force should be increased by 10% to 25%.

III. Spot Welding of Aluminum-Coated Steel Sheets

Aluminum-coated steel sheets are divided into two types: one with a surface coating of AL-Si alloy (20-25μm thick) for high-temperature resistance up to 640 degrees Celsius, and the other with a pure aluminum coating (2-3 times thicker than the first type) for corrosion resistance. Both types can achieve strong weld points when spot welding.

Due to the good electrical and thermal conductivity of the coating, a larger welding current is required. When welding corrosion-resistant aluminum-coated steel, a thicker coating requires higher welding heat, necessitating a larger welding current and a smaller welding pressure to increase the welding heat.

IV. Spot Welding of Aluminum Alloys

Spot welding of aluminum alloys has relatively poor weldability, especially for heat-treated strengthened aluminum alloys, due to the following reasons:

1. Aluminum alloys have a low resistivity and high thermal conductivity, requiring a strong specification with welding current approximately 4-5 times that of low carbon steel of the same thickness. A high-power welding machine is needed.

2. The surface is prone to overheating, leading to the diffusion of copper ions from the electrode to the pure aluminum coating, causing mutual adhesion between the electrode and the workpiece, increasing electrode wear, and reducing the surface quality of the molten core.

3. Aluminum alloys have a narrow plastic temperature range and a large linear expansion coefficient. Larger electrode pressure is required to avoid cracks caused by excessive internal tensile stress during the solidification of the molten core. For aluminum alloys with a high tendency for cracking, the forging pressure should be increased to allow sufficient plastic deformation during solidification, reduce tensile stress, and prevent crack formation.

4. The surface is prone to oxide film formation, requiring strict cleaning before welding.

Given these characteristics of aluminum alloy spot welding, the spot welding machine used must have the following features:

1. Ability to provide large current in a short time, with a fast current rise rate and high equipment power.

2. Adjustable waveform of the current with a gradual rise and fall.

3. Programmable pressure curve, providing step-shaped or saddle-shaped electrode force.

4. Low inertia and frictional resistance of the machine head, with good dynamic response of the electrode.

5. Accurate control of welding parameters, unaffected by fluctuations in the power grid voltage.

Before welding: Precision setting of welding specifications based on different workpieces and materials, including ① welding current (waveform and effective value) ② welding time ③ welding pressure.

During the welding process: Precise setting and control of flexible welding current and welding pressure, collection of dynamic resistance curves during the welding process, capturing the dynamic patterns of resistance welding.

After welding: Utilizing AI (Artificial Intelligence) technology for non-destructive analysis and assessment of the quality of spot (projection) welding for users.

A diverse range of precision welding products with a human-machine interaction interface.

Among them, precision (inverter) energy storage welding adopts a three-stage intelligent charging mode (patented by the company in the field of commerce) with 40KJ, capable of completing a 1000V charge within 1 second.