Alleima® 254 SMO
UNS S31254 | EN 1.4547
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About
Alleima® 254 SMO is a high-alloy austenitic stainless steel developed for use in seawater and other aggressive chloride-bearing media. The steel is characterized by the following properties:
- 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
*The PRE is defined as, in weight-%, PRE = %Cr + 3.3 x %Mo + 16 x %N
Trademark information: 254 SMO is a trademark owned by Outokumpu OY.
Standards
- UNS: S31254
- EN Number: 1.4547
- EN Name: X1CrNiMoCuN20-18-7
- W.Nr.: 1.4529**
- AFNOR: Z1 CNDU 20.18.06AZ*
* Obsolete. Replaced by EN.
** Nearest equivalent grade.
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
- UNS S31254 (Alleima® 254 SMO) in the form of seamless pipe has been approved by the American Society of Mechanical Engineers (ASME) for use according to ASME Boiler and Pressure Vessel Code section VIII, div. 1. However, there is no approval for UNS S31254 in the form of seamless tube, but according to the ASME paragraph UG-15 it is allowed to use the design values for seamless pipe according to ASME section VIII, div. 1 also for seamless tube.
- NACE MR 0175 (sulphide stress cracking resistant material for oil field equipment).