Roller welding

Roller welding – This is a type of resistance welding in which the connection of parts consists of a series of individual weld spots that overlap one another. The weld is formed by mechanical action. Therefore, this type of welding is classified as pressure welding. It is performed on specialized welding machines equipped with one or two rotating disc rollers that serve as electrodes. The method roller welding  It is possible to weld metal with a thickness of 0.2 mm to 3 mm. Steel of this thickness is often used to make gas tanks, various pipes, barrels, etc.

Spot welding

Spot welding  Allows you to firmly join parts with a beautiful, neat seam. The process involves the following steps:

• The workpiece is prepared for joining to a clean surface. Grease stains and oxides prevent the flow of welding current and, consequently, a good metal bond;
• The workpieces are placed on top of each other and clamped with disk electrodes. The clamping force corresponds to the thickness of the metal;
• Then, welding current is applied to the rollers, which serve as electrodes. The metal in the contact zone with the workpiece begins to heat up and melt. A certain mechanical pressure is applied, bonding the metal;
• As the workpiece rolls, weld spots form between the rollers. These may overlap in some places.

Spot welding  Produces welded joints quite quickly. No special means are required to protect the melted area from oxidation. This makes the welding process less labor-intensive. The weld spots are capable of bonding parts very strongly and withstanding a certain load.

Seam roller welding

Seam roller welding – This is the same as roller welding. The welding principle is no different from spot roller welding. Seam roller welding  is performed in three ways:

1) Continuous;

2) Intermittent;

3) Stepping.

The continuous welding method involves continuous movement of the parts and the supply of current. It welds sheet metal up to 1 mm thick made of mild steel. This method is primarily used for less sensitive applications. A disadvantage is the frequent overheating of the welding electrodes and parts. Therefore, this method is rarely used.

The discontinuous welding method joins parts that continuously rotate during the welding process, but the welding current is interrupted. The sheet thicknesses being welded are up to 3 mm. A well-balanced ratio of roller speed to current pulse frequency ensures a good seal. This method is more efficient and has become more widespread. The welding rollers and workpieces do not overheat, and the weld quality is good.

The stepping method involves intermittent movement of the parts (step by step). When the roller stops, a high current is applied, which joins the metal. Sheets up to 3 mm thick can be welded. Overheating of the rollers and the part is minimal. This method is successfully used for joining aluminum alloys and clad metals. Seam roller welding They are equipped with rollers that can withstand heavy loads. Therefore, they are made of metals that can withstand such loads. Copper and bronze alloys are used for this purpose. They are resistant to deformation and overheating.