Introduction

Material to F44 Super Austenitic Stainless Steel is described as a 6% Mo super austenitic stainless
steel. The steel combines moderate mechanical strength (typically over 300 MPa yield strength) and high ductility with excellent corrosion resistance in seawater and a variety of industrial environments. Typically the alloy has a PREn(Pitting Resistance Equivalent) of 42-44 which ensures that the resistance to pitting corrosion is high. In addition, the steel provides good resistance to crevice corrosion.
Ambient and subzero temperature notch ductility is very good. These attributes mean that this high molybdenum stainless steel can be used successfully as an alternative to 300 series austenitic stainless steels (such as type 316) in applications where higher mechanical strength and/or
enhanced resistance to pitting and crevice corrosion is required. This alloy possesses a lower yield strength than that of duplex stainless steel (and much lower than that of super duplex steel) and pitting resistance which is comparable to super duplex stainless steel (such as UNS S32760 / S32750).

Applications

F44 Super Austenitic Stainless Steel is ideally suited for use in halide environments and widely used in the chemical, marine, oil and gas industries. Typical applications include pumps, valves, heat exchangers, flanges and manifolds.

Quality Standard

ASTM A182 Standard Specification for Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts
EN 10088 part3 stainless steel

All Grades Comparison

ASTM A182 :F44

EN1008:1.4547

Chemical Composition(%)

F44 C:0.02max, Si:0.8max, Mn:1.0max, P:0.030max, S:0.010max, Cr:19.5-20.5, Ni17.5-18.5, Mo:6.0-6.5, Cu:0.50-1.00, N:0.18-0.22

1.4547 C:0.02max, Si:0.7max, Mn:1.0max, P:0.030max S:0.010max, Cr:19.5-20.5, Ni17.5-18.5,Mo:6.0-7.0, Cu:0.50-1.00, N;0.18-0.25

Mechanical Properties (Annealed)

Hardness (HB):260max

Tensile Strength (Mpa):650-850

Yield Strength (Mpa):300-340

Elongation (%) (Long.):35min

Impact Value (J) (Long.):100min

Corrosion Resistance

F44 Super Austenitic Stainless Steel offers higher resistance to abrasion, erosion and cavitation erosion than other austenitic stainless grades such as 316. F44 Super Austenitic Stainless Steel has excellent resistance to corrosion in sea water and concentrated halide environments, with good resistance to crevice corrosion in seawater.

Welding

F44 Super Austenitic Stainless Steel is readily weldeable with welding procedures used for other austenitic stainless steel specifications. Welding should be carried out at the lowest heat possible as due to its austenite structure it can be prone to hot cracking.

Mill′s test certificate

EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.