Working around sigma

30 October 2019

In his article ‘Duplex stainless steel: Working around sigma’, Shane Turcott, Principal Metallurgist at Steel Image Inc., discusses how sigma phase is the Achilles heel of duplex stainless steel. Sigma phase cripples the corrosion resistance of duplex and essentially turns expensive stainless steel into cheap carbon steel. 

“It is because of sigma phase that duplex stainless steel has to be fabricated in a very different manner than the more common carbon and austenitic stainless steels,” Turcott writes. “It also presents unique issues for operators, inspectors, and reliability personnel to be aware of and mitigate when using duplex stainless steel within their facilities.”

For the full article, please email Catarina Muia at for the article PDF.