LOSTWAXInvestment Casting

CE3MN (5A) — 25Cr-7Ni-Mo-N super duplex stainless steel

Designation

Grade
CE3MN (5A)
UNS
J93404
Standard
ASTM A890/A890M, A995/A995M Gr. 5A
Density
≈ 7.80 g/cm³
Usual delivery condition
Solution annealed and quenched

Chemical composition

ElementMass fraction, %
C≤ 0.03
Mn≤ 1.50
Si≤ 1.00
Cr24.0–26.0
Ni6.0–8.0
Mo4.0–5.0
N0.10–0.30
Febal.

Main elements only. Phosphorus, sulphur and residual-element limits are specified in the standard and are not reproduced here.

Mechanical properties

ConditionTensile strength Rm, min. (MPa)Yield strength Rp0.2, min. (MPa)Elongation, min. (%)
Solution annealed and quenched69051518

Minimum values (or ranges) for separately cast test bars as specified in ASTM A890/A890M, A995/A995M Gr. 5A.

Characteristics

Corrosion and oxidation behaviour
Very good resistance in seawater and chloride-bearing media
Weldability
Possible with qualified procedure; preheat and/or post-weld heat treatment as specified
Machinability
Difficult; rigid set-ups, low cutting speeds or grinding
Typical applications
Valves Pumps Offshore Marine Chemical processing

International cross-reference

SystemDesignationRelationship
EN1.4469 (GX2CrNiMoN26-7-4), EN 10283Similar composition
UNS (wrought)S32750Comparable properties

Casting and processing considerations

The phase balance and freedom from intermetallic phases such as sigma depend on a correct solution anneal followed by rapid quenching; slow cooling of heavy sections is the main risk. Ferrite content, impact toughness and corrosion testing are frequently specified as acceptance tests and should be defined at the enquiry stage.

Reference data compiled from the cited standards for orientation. Always work from the current edition of the governing specification; values are not a guaranteed LOSTWAX delivery specification.

CD3MN (4A)