X2CrNiMoN22-5-3 (2205 Duplex)

Description

X2CrNiMoN22-5-3 (EN 1.4462 / UNS S31803 / S32205) per EN 10088. Balanced ferritic-austenitic microstructure gives Rp0.2 >=450 MPa — 2x higher than 316L — combined with PRE=35 pitting resistance. Outstanding resistance to chloride SCC (a key failure mode of austenitic stainless). Standard for offshore topside piping, desalination plant, chemical vessels and seawater handling.

Key Properties — Solution Annealed (plate)

Rm (Tensile Strength)

620

MPa

Re / Rp0.2 (Yield)

450

MPa

A₅ (Elongation)

≥ 20.0

Hardness

— – 293

E (Young's Modulus)

200

GPa

Density

7.80

g/cm³

Main Designations (10)

Standard Body	Designation	Country / Region	Note
EN	X2CrNiMoN22-5-3 / 1.4462	EU
UNS	S31803 / S32205	USA (UNS)
ASTM	A240 / A276 UNS S32205	USA
BS EN	318S13	UK
JIS	SUS329J3L	Japan
GOST	08H22N6T (nearest)	Russia
SS	2377	Sweden
JUS	C.4750D	Yugoslavia	Duplex Cr-Ni-Mo-N stainless; JUS C.B2.080
ISO	X2CrNiMoN22-5-3	International
ASME	SA-240 UNS S31803	USA

Standards (10)

#	Standard Body	Designation	Country / Region	Note
1	EN	X2CrNiMoN22-5-3 / 1.4462	EU	—
2	UNS	S31803 / S32205	USA (UNS)	—
3	ASTM	A240 / A276 UNS S32205	USA	—
4	BS EN	318S13	UK	—
5	JIS	SUS329J3L	Japan	—
6	GOST	08H22N6T (nearest)	Russia	—
7	SS	2377	Sweden	—
8	JUS	C.4750D	Yugoslavia	Duplex Cr-Ni-Mo-N stainless; JUS C.B2.080
9	ISO	X2CrNiMoN22-5-3	International	—
10	ASME	SA-240 UNS S31803	USA	—

All values in wt.%

Carbon

≤ 0.0300

Silicon

≤ 1.0000

Manganese

≤ 2.0000

Chromium

21.0000 – 23.0000

Nickel

4.5000 – 6.5000

Molybdenum

3.0000 – 3.5000

Nitrogen

0.1400 – 0.2000

Element	Symbol	Min %	Max %	Typical %
Carbon	C	—	0.0300	0.0150
Silicon	Si	—	1.0000	0.4000
Manganese	Mn	—	2.0000	0.8000
Chromium	Cr	21.0000	23.0000	22.5000
Nickel	Ni	4.5000	6.5000	5.5000
Molybdenum	Mo	3.0000	3.5000	3.1000
Nitrogen	N	0.1400	0.2000	0.1600

Mechanical Properties

Condition	Code	Rm min MPa	Rm max MPa	Re min MPa	Re max MPa	A₅ min %	Z %	KV J	HB min	HB max	HRC min	HRC max	E GPa
Solution Annealed (plate)	+AT	620	—	450	—	20.0	—	—	—	293	—	—	200.0

Physical Properties

Density

7.800

g/cm³

Melting Point

1350–1450

°C

Young's Modulus

200.0

GPa

Poisson's Ratio

0.300

—

Thermal Conductivity

19.0

W/m·K

Thermal Expansion

13.00

×10⁻⁶ /K

Specific Heat

480

J/kg·K

Electrical Resistivity

0.8600

µΩ·m

Magnetic

Yes

Heat Treatment

Solution Annealing

Temperature:1020°C – 1100°C

Medium:Rapid water quench

Duration:Sufficient

Cooling:Water quench — must be rapid

Hardness After:<=HB 293

Must be rapid. Slow cooling causes sigma phase.

AVOID sustained range

Temperature:600°C – 950°C

Medium:N/A

Duration:N/A

Cooling:N/A

Hardness After:N/A

Sigma phase, chi phase and alpha-prime embrittlement occur. Never allow slow cooling through this range.

Machinability

Machinability Rating

relative to AISI B1112 = 100%

40.0%

Difficult

Turning Speed (HSS)

m/min

Turning Speed (Carbide)

m/min

Feed Rate (Turning)

0.110

mm/rev

Drilling Speed (HSS)

m/min

Milling Speed (Carbide)

m/min

Coolant	High-pressure flood coolant mandatory
Chip Formation	Short-medium chips; high cutting forces (~2x 316L)
Tool Material	Carbide M10 TiAlN; reduce speed 25% vs 316L
Surface Finish	Ra 0.4-1.6 um

Significantly harder to machine than 316L. High cutting forces. Maintain constant chip load.

Applications

Oil & Gas

Offshore topside piping, manifolds, wellhead and HIPPS components.

Chemical

Chemical plant vessels, heat exchangers and piping in chloride service.

Desalination

Seawater reverse osmosis pressure vessels and high-pressure piping.

Marine

Structural marine components, propeller shafts and offshore platform decks.

Technical Notes

✅

2205 vs 316L

2205: 2x strength, better pitting (PRE 35 vs 25), SCC resistant (vs 316L susceptible). 316L: lower cost, more supplier base, easier to machine. Use 2205 when: Cl->500 ppm, T>50 C, or SCC risk exists.

🔥

Weldability

Good. Use 2209 filler. Interpass max 150 C. Heat input 1.0-2.5 kJ/mm. PWHT not required but solution anneal recommended for critical applications.