Alleima 254 SMO – Seamless tube, high-alloy UNS S31254

Alleima 254 SMO is a high-alloy austenitic stainless steel developed for use in seawater and other aggressive chloride-bearing media. The grade is characterized by:

• Excellent resistance to pitting and crevice corrosion, PRE ≥ 42.5*
• High resistance to general corrosion
• High resistance to stress corrosion cracking
• Higher strength than conventional austenitic stainless steels
• Good weldability

* PRE = %Cr + 3.3 × %Mo + 16 × %N (weight-%)

254 SMO is a trademark owned by Outokumpu OY.

MATERIAL

• UNS S31254
• EN 1.4547

STANDARDS

• UNS: S31254
• EN Number: 1.4547
• EN Name: X1CrNiMoCuN20-18-7
• W.Nr.: 1.4529 (nearest equivalent grade)
• AFNOR: Z1CNDU20.18.06AZ (obsolete, replaced by EN)

PRODUCT STANDARDS

• Seamless tube and pipe: ASTM A269, A213, A312, NFA 49-217, EN 10216-5
• NORSOK MDS R11/R18, IOGP S-563 MDS IR111/111S/IR118/IR118S
• Welded tube and pipe: ASTM A249, A269, A312, A358, A409
• Fittings: ASTM A182
• Bar: ASTM A276, A479, EN 10088-3
• Forged products: ASTM A473

APPROVALS

• ASME Boiler and Pressure Vessel Code section VIII, div. 1 – approved as seamless pipe. According to ASME UG-15, the design values for seamless pipe may also be used for seamless tube.
• NACE MR0175 (sulphide stress cracking resistant material for oil field equipment)