Handle and Fabricate Weather Resistant Steels

Weathering resistant steels require special attention in their handling, fabrication and welding.

Use and Handling of Weathering Steels

As for the normal structural steels (such as AS/NZS 3678-250 XLERPLATE®) care should be exercised in the handling of weathering steels. These steels must be kept free from oil, chalk marks, paint, concrete splatter and similar staining by other construction materials. Any foreign matter adhering to the steel needs to be removed as soon as possible. 

Care should also be exercised in design as run off staining may occur to the surrounding area depending on the nature of the surface, eg bare concrete. Contact with clothing may also result in staining in the same manner as for normal structural steels. 

Welding

The weathering steels can be readily welded both to other plates of weathering steel and to plain carbon steels. When welding these steels, low hydrogen electrodes should be used.

Care should also be taken in the selection of the welding procedure. Consult the Welding Institute of Australia's Technical Note Number 1 for details (note weathering steels are Group 5 materials as are AS/NZS 3678-350 XLERPLATE® grade structural steels). 

The need to colour match weld areas is dependent on the end result required. Over a period of 1-2 years, there is little difference between standard electrodes and specialised electrodes designed for this type of steel (E70XX). However, over extended time periods, the standard weld metal discolours and corrodes at a different rate to the weather resistant steel. Where close colour matching is required, such as for architectural applications, special electrodes must be used (contact a welding consumable manufacturer). However, when welding thin plate (<12mm) there is sufficient dilution of the parent plate into the weld metal to result in a close colour match.