Iron powders

Welding

Thanks to the quality and productivity advantages it offers, iron powder has achieved a wide acceptance as a coating component for welding electrodes. A growing acceptance of cored-wire welding has also contributed to a more widespread use of iron powders.

Höganäs continues to develop and improve its selection of iron powders for welding applications, to ensure customers a product choice which exactly suits their needs.

Increased productivity

By adding iron powder to the welding electrode coating, it can be made thicker without any increase in the content of slag builders. This reduces raw material costs and improves energy utilization.

Iron powder in the coating has a cooling effect on core wire, as the preheating of iron particles dissipates the generated heat. This means a higher amperage can be used without risk of overheating and, as a result, a higher melting rate can be achieved.

The illustrations below highlight the potential productivity enhancements.

Improved welding characteristics

The welding operation itself is also enhanced. Iron powder in electrode coatings lend to:

• Improved arc stability,
• Easier reignition,
• Reduced spatter,
• Smoother bead shapes, and
• Easier slag removal.

Better weld metal quality

In addition to giving higher productivity and improved welding characteristics, iron powder added to electrode coatings also favorably affects the weld metal quality.

The cooling effect of the additional iron allows quicker solidification of the weld metal. This creates a fine-grained microstructure, with resulting improvements in weld metal strength and ductility. Since it also reduces base metal dilution, overall weld quality is also improved.

Cored-wire welding

Use of flux-cored and metal-cored wire has grown significantly in recent years, particularly in heavy industries and where automated welding is possible. Increased productivity and improved weld metal quality are two major reasons. Iron powder is used to increase the weld deposit, and also to modify the weld composition - and thereby its mechanical properties.