Weld overlay is a welding process where one or more metals with specific characteristics are applied to a base metal to improve desirable properties or to restore the original dimension of the component.
Weld overlay may also be referred to as cladding, hard facing, weld cladding or weld overlay cladding.
How does welding differ from weld overlay?
Instead of general welding which is joining two pieces of material together, weld overlay applies a corrosive resistant or hard facing layer onto the parent material.
What is the purpose of weld overlay?
The main purpose for weld overlay is its use for corrosion resistance or wear resistance though as previously mentioned it is also used to restore the original dimension of the component.
Whilst most components will have corrosion allowance built into their wall thickness the wastage rate can still be excessive for certain materials such as carbon steels or low alloy steels.
Weld overlay provides a surface protection which then allows the substrate material to provide strength requirements to meet codes and standards, allowing the equipment to operate in a cost effective manner.
Where can weld overlay be applied?
Weld overlay can be applied to many components ranging from pipes, fittings, valves and vessels and is most commonly used within the oil and gas industry.