Duplex Stainless Steels have a structure that contains both ferrite and austenite. Duplex alloys have higher strength and better stress corrosion cracking resistance than most austenitic alloys and greater toughness than ferritic alloys, especially at low temperatures. The corrosion resistance of duplex alloys depends primarily on their composition, especially the amount of chromium, molybdenum, and nitrogen they contain.

Duplex alloys are often divided into three sub-classes:

Lean Duplex (ATI 2102　duplex, ATI 2003　duplex, and ATI 2304　duplex alloys),

Standard Duplex (ATI 2205　duplex alloy),

Superduplex (ATI 255　duplex and UNS S32760 duplex alloys).

Duplex Statinless Steel Pipe
1.Standard AISI, ASTM
2.Place of Origin: China (Mainland)
3.Brand Name: SunnySteel
4.Delivery Conditions: Annealed and Pickled
5.Shape: round&square
6.Certificates: PED / AD2000 W0 / DNV
7.Material: UNS N06600,UNS N08825,UNS N08925,
304/304L,316/316L,316Ti,310S,321/H,347H,317L,400,800H,904L,UNS S31803, UNS S32750, ...
8.Standards:
ASTM B407,ASTM B163
ASTM A213,ASTM A269,ASTM A511,ASTM A312/ASME SA312,ASTM A789, ASTM A790
9.Application:
Petrochemical industrial pipe
Pipe pharmaceutical industry
Food industry management
Aerospace tube
Boiler heat exchange tube
Pipe construction and decoration industries
Automation and other industrial pipe
10.Dimensions:
O.D. 1/4NB SCH10S, SCH40S, SCH80S, SCH160, SCH XXS
O.D. 18NB SCH10S, 40S, SCH80S
11.Payment Terms: T/T, L/C
12.Minimum Order Quantity: Negotiable
13.Load Port: shanghai
14.Packaging Details: plywood boxes; plastic bags
15.Delivery Time: 30 days
16.Supply Ability: 300 Ton/Tons per Month

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.

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.