General Duplex stainless steel information

2205 is the most widely used duplex (ferritic/austenitic) stainless steel grade. It finds applications due to both excellent corrosion resistance and high strength. The standard duplex S31803 composition has over the years been refined by many steel suppliers, and the resulting restricted composition range was endorsed as UNS S32205 in 1996. Duplex S32205 gives better guaranteed corrosion resistance, but for much of the Duplex S31803 currently produced also complies with Duplex S32205. 2205 is not generally suitable for use at temperatures above 300ºC as it suffers from precipitation of brittle micro-constituents, nor below -50ºC because of its ductile-to-brittle-transition.

Duplex Heat Resistance

Although 2205 has good high temperature oxidation resistance, this grade - like other duplex stainless steels - suffers from embrittlement if held for even short times at temperatures above 300ºC. If embrittled, this can only be rectified by a full solution annealing treatment. Duplex stainless steels are almost never used above 300ºC.

Duplex Heat Treatment

Solution treatment (annealing) - heat to 1020ºC-1100ºC and cool rapidly. This grade cannot be hardened by thermal treatment, but does work harden.

Pipes & Tubes:

We have large inventory of pipes. Available in a comprehensive range of both Metric and Imperial dimensions. RSC offer probably the widest range in worldwide, in numerous grades consisting of some 15000 line items within the following typical

Range: 15 NB to 1200 NB & 3 mm OD to 914mm OD

ASTM / ASME : A / SA 790

Sch: 5s, 10s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS & 0.2 mm to 40 mm wall thickness.

Type:
SEAMLESS (SMLS)
ELECTRIC RESISTANCE WELDED (ERW)
ELECTRIC FUSION WELDED (EFW)
SUBMERGED ARC WELDED (SAW)

FORM: Round, Square, Rectangular, Hydraulic Etc.

Pipe Fittings:

RSC is manufacturer of comprehensive range of Seamless, Welded, Threaded and Socket Weld fittings, in numerous combinations covering elbows, tees, reducers, nipples, caps and unions etc. RSC offer possibilities to make every connection and combination. Also available for instrumentation tube is a full range of single and twin ferrule compression fittings.

Fittings are supplied in general accordance with following dimensional and material specifications:

Butt Weld fittings      ASME B16:9 and B16:25.

High Pressure Fittings (3000lb/6000/9000lb) - Threaded and Socket Weld - BS 3799

Low Pressure Fittings (150lb) - Threaded BS 1740

Range: 15 NB to 1200 NB (Butt Weld)

             15 NB to 100 NB (Threaded & SW)  

ASTM / ASME

SA815 (Butt Weld)
SA182 - Forged Fittings
ASTM / ASME SA790 - Fittings manufactured from pipe

DIN 2605 / 2615 / DIN 2616 / DIN 2617 DIN Weld Fittings

Sch.: 5s, 10s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS

Type: Seamless (SMLS), Welded (ERW), WX.

Flanges:

Flanges are available to suit all pipes. The most popular being ASA - standard stock in 150lb to 900lb pressure rating, albeit also available in 1500lb and 2500lb ratings. Other standard stock includes BS 4504 PN 10 / PN 16 with PN 40 and PN 64 also being available on short lead time.

The three main types of flange are:-

• Slip - on
• Blind
• Weld Neck
• Socket Weld 

Faces are typically raised face with a machined spiral facing to facilitate. Ring Type Joint facings are also commonly used in Petrochemical applications where the hub of the flange is thicker with an RTJ recess machined in to the face.

Related Specification

ASTM/ASME SA182 / ASME B16.5
BS 4504
BS 10
DIN 2576 / 2633 / 2635 / 2527

Fasteners:

Round Bar:

Duplex Applications

Chemical processing, transport and storage,
Oil and Gas exploration and processing equipment,
Marine and other high chloride environments,
Pulp and paper digesters, liquor tanks and paper machines.

Duplex Corrosion Resistance

Excellent general corrosion resistance; superior to Grade 316 in most environments. Excellent resistance to localized corrosion including intergranular, pitting and crevice corrosion; the CPT of 2205 is generally at least 35ºC. The grade is also resistant to chloride stress corrosion cracking (SCC) at temperatures of up to about 150ºC. Grade 2205 will often perform well in environments which cause premature failure of austenitic grades. It has better resistance to sea water then Grade 316.