Appropriate temperature for welding LSAW steel pipes

Welding is a manufacturing process and technology that joins metal or other thermoplastic composite materials through the application of heat, temperature, or pressure. There are three common welding methods.

Fusion Welding:

The workpiece is heated to form a molten pool. After cooling and solidification, the molten pool forms a solid connection. Filling materials can be added if necessary. This method is suitable for pressureless welding of various metals and alloys.

Pressure Welding:

This method requires pressure to be applied to the welded parts. It is used for various metal materials and certain metal processing applications. No filler material is needed.

Brazing:

Uses a filler metal with a lower melting point than the base metal. The liquid solder wets the base metal, fills the joint gap, diffuses into the base metal, and joins the parts. This method is suitable for welding different metals or materials with uneven welding results.

For low carbon steel LSAW pipes, the welding temperature is controlled between 1250°C to 1460°C, which is suitable for pipe wall thicknesses of 3 to 5 mm.

Welding Temperature Control

- Insufficient Heat: When the input heat is insufficient, the welded edge of the LSAW steel pipe cannot reach the required welding temperature, resulting in a weak weld that does not melt or penetrate properly.

- Excessive Heat: When the input heat is too high, the weld edge exceeds the welding temperature, causing overheating or the formation of molten droplets.

Pressure Welding Features

A common feature of various pressure welding methods is the use of pressure without filler material. Examples include diffusion welding, high-frequency welding, and cold pressure welding. These methods do not involve melting, eliminating issues like alloy element burn-off and harmful element intrusion. This simplifies the welding process and improves safety and health conditions. Additionally, the lower heating temperature and shorter heating time reduce thermal impact, making it possible to weld materials that are difficult to join with fusion welding. Pressure welding often produces high-quality joints with strength equivalent to the base metal.

Union Steel Industry is a professional manufacturer of LSAW steel pipes in China. For more information, please contact: sales@union-steels.com