Causes of slag inclusion in spiral tube

Spiral pipe, also known as spiral steel pipe or spiral welded pipe, is the low carbon structural steel or low alloy structural steel strip according to a certain helix Angle (called forming Angle) rolled into a tube blank, and then welded together the pipe seam made of it can be used to produce large diameter steel pipe with a narrower strip. What is the cause of slag inclusion in the production of spiral pipe?

1, raw materials (including base metal, welding wire, flux) more inclusions.

2, the selection of improper welding process parameters, is not conducive to the emergence of slag.

3, multi-layer welding between the layers is not clean.

According to the production characteristics of the direct-seam submerged arc welding pipe, the reason of slag inclusion in the weld caused by unclean cleaning between layers can be excluded.

After inspecting the base metal before welding and replacing the welding wire and flux, the proportion of slag inclusion in the weld fusion line is only slightly reduced, indicating that the inclusion in the raw material is not the main cause of slag inclusion.

Therefore, the main reason of slag inclusion in spiral tube fusion line is improper welding process parameters.