Weldability Aspects of Ferritic Stainless Steels

Ferritic stainless steels have recently drawn greater attention owing to their lower costs and better resistance to stress corrosion cracking than austenitic stainless steels. Although these properties make the alloy commercially attractive they still exhibit several significant draw backs that limit their use Ferritic stainless steels are less weldable than austenitic ones. A pronounced grain growth takes place in the heat affected zone and carbide precipitation occur at the grain boundaries. This makes the weld more brittle and decreases its corrosion resistance Furthermore cracks can occur in the weld metal when it cools down.

When welding stainless steels care must be taken that welding process does not affect either the corrosion resistance of the weldment or its mechanical properties. This article covers what effects the welding process can have on the metallurgy of ferritic stainless steels, selection of consumable and suggests practical advice on how potential problems can overcome