F55 Steel ( UNS S32706 / 1.4501 )

Description

Material grades and equivalents：UNS S32706 / 1.4505 / F55 / S27603 / 022Cr25Ni7Mo4WCuN / X2CrNiMoWN25-7-4

Special properties:

The characteristic features of high strength and corrosion resistance exhibited by the dual microstructure (50% Austenite, 50% Ferrite) associated with Duplex Stainless Steels, are enhanced by a further addition of Chromium (to 25%), and also Tungsten and Copper.

The alloy’s pitting and Crevice Corrosion resistance is better than Standard F51 duplex, The pitting index (PREN) is increased to 40 min from standard F51 Duplex value of 33 min.

Thin sections (Tubulars) are capable of being cold worked to give yield strength of 105 KSI min.

To optimise mechanical properties, avoid clinking, and to avoid deleterious intermetallics within the microstructure; special high temp forming and heat treatment control practices must be followed during processing.

F55 Duplex Stainless SteelChemical composition:

Weight %	C	Si	Mn	S	P	Cr	Ni	Mo	N	Cu	W
Min.						24,00	6,00	3,00	0,20	0,50	0,50
Max.	0,030	1,00	1,00	0,010	0,030	26,00	8,00	4,00	0,30	1,00	1,00

F55 Duplex Stainless Steel Mechanical Properties:

UNS S32706 1.4501 F55	Yield strength Rp0.2,	Tensile strength Rm,	Elongation	Hardness	Impact, Charpy-V, -46ºC	Pre
	MPa	MPa	[%]	[HB]	[J]
BAR	≥ 550	≥ 750	≥ 25	≤ 310	≥ 45	≥ 40
PLATE CR (COIL)	≥ 550	750 – 1000	≥ 25	≤ 310	≥ 45	≥ 40
PLATE HR (COIL)	≥ 550	750 – 930	≥ 25	≤ 310	≥ 45	≥ 40
PLATE (QUARTO)	≥ 550	750 – 930	≥ 25	≤ 310	≥ 45	≥ 40

F55 Duplex StainlessSteel Physical properties:

Density (Kg/m3)	7810
Magnetic Permeability (20°C)	33
Young’s Modulus (kN/mm2)	199
Specific Electrical Resistance, 20°C (µΩ.m)	0.8
Mean coefficient of thermal expansion, 20-300°C (m/m/oC)	11.1 x 10-6
Specific Heat, 20°C (J/kg.K)	475
Thermal conductivity, 20°C (W/m.K)	14.2
Fracture Toughness, kQ (MPa/m2)	98

F55 Duplex Stainless Steel  Specifications：

1.4501	ASTM A276/A476
X2CrNiMoCuWN 25-7-4	UNS S32760 (Super Duplex 32760)
Z3CND25.06Az	ASME A182 F55
Norsok MDS D57	CD3MWCuN (Cast grade)
SAF32760	25Cr

Key Features:

• Excellent corrosion resistance in a wide variety of corrosive chemicals

• Pitting Resistance Equivalent number (PREN) of >40

• Outstanding resistance to pitting and crevice corrosion in seawater and other chloride containing environments

• Critical Pitting Temperature exceeding 50°C

• High strength compared to austenitic and 22%Cr duplex stainless steels

• Excellent ductility and impact strength at both ambient and sub-zero temperatures

• High resistance to abrasion, erosion and cavitation erosion

• Excellent resistance to stress corrosion cracking in chloride containing environments

• Listed in NACE MR 0175 for sour service

• ASME Approval for Pressure Vessel application

F55 ( UNS S32706 / 1.4501 ) Duplex Stainless Steel Applications

• Process industry components in nitric acid, dioxide, polypropylene & PVC

• production, caustic evaporators

• Equipment handling organic & fatty acids

• Marine industry and shipbuilding propellers, shafts, rudders, shaft seals, pumps, bolts, fasteners, valves, instrumentation

• Oil and chemical tankers

• Oil & Gas industry pumps, valves, pipe, vessels, wellhead equipment, subsea equipment

• Pollution control systems, fans and pumps, wet scrubbers, incinerators, flue gas desulphurisation (FGD)

• Pulp & paper industry components such as black liquor heater tubes, digester blow valves, rotary feed valves, I.D.fans, brownstock washers, precipitators, bleaching components

• Food Industry applications including sugar cane centrifuges, corn and vegetable processing plant

• Agrochemicals production such as fertilisers (based on wet phosphoric acid)
  Sewage treatment, seawater cooling, desalination plants