Corrosion of Weld Seams

Case

  • Welded steel tube manufacturing
  • The galvanized steel tube is formed, welded, deburred and metallized at a temperature 350-400° C
steel tubes

Challenge

Corrosion: the weld seam becomes depleted of zinc due to its low boiling point versus the melting point of steel. This effectively eliminates the benefit of galvanizing.

Our coating solution

Metallization of zinc on the welded seam area by wire flame spray

Benefits

  • Easy installation on the tube line
  • Tube temperature not critical to deposition, can even be down to 300°C
  • Low capital investment and simple maintenance: Z-Jet, Top-Jet
  • Full automation with the latest generation of flame spray equipment: MasterJet® Auto IV
  • Excellent and even coating quality: highly adjustable particle and spot size leading to a dense coating with low oxidation, smooth surface and good adherence to steel
  • Cost-effective solution:
  • Deposition efficiency >85 % (vs 45-65 % for arc spray).
  • Less overspray due to narrow spray pattern
  • Far less zinc fumes: Zinc fumes and dust emissions drop to a fraction of that of arc spray, requiring less investment in fumes extraction

The flame spray system is:

  • Economical (low CAPEX)
  • Easy to use and maintain