Type 22Cr duplex
Ferritic/austenitic stainless steel alloys with 30 u PREN u 40 and Mo u 2,0 % mass fraction.
EXAMPLES UNS S31803 and S32205 steels.
Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards
Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global Standards