Description

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 ***2　duplex, ATI ***3　duplex, and ATI ***4　duplex alloys),

Standard Duplex (ATI ***5　duplex alloy),

Superduplex (ATI **5　duplex and UNS S****0 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 / AD***0 W0 / DNV
7.Material: UNS N****0,UNS N****5,UNS N****5,
**4/**4L,**6/**6L,**6Ti,**0S,**1/H,**7H,**7L,**0,**0H,**4L,UNS S****3, UNS S****0, ...
8.Standards:
ASTM B**7,ASTM B**3
ASTM A**3,ASTM A**9,ASTM A**1,ASTM A**2/ASME SA**2,ASTM A**9, ASTM A**0
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
*0.Dimensions:
O.D. 1/4NB SCH*0S, SCH*0S, SCH*0S, SCH**0, SCH XXS
O.D. *8NB SCH*0S, *0S, SCH*0S
*1.Payment Terms: T/T, L/C
*2.Minimum Order Quantity: Negotiable
*3.Load Port: shanghai
*4.Packaging Details: plywood boxes; plastic bags
*5.Delivery Time: *0 days
*6.Supply Ability: **0 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 **6 in most environments. Excellent resistance to localized corrosion including intergranular, pitting and crevice corrosion; the CPT of ***5 is generally at least *5ºC. The grade is also resistant to chloride stress corrosion cracking (SCC) at temperatures of up to about **0ºC. Grade ***5 will often perform well in environments which cause premature failure of austenitic grades. It has better resistance to sea water then Grade **6.

Duplex Heat Resistance

Although ***5 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 **0ºC. If embrittled, this can only be rectified by a full solution annealing treatment. Duplex stainless steels are almost never used above **0ºC.

Duplex Heat Treatment

Solution treatment (annealing) - heat to ***0ºC****0ºC and cool rapidly. This grade cannot be hardened by thermal treatment, but does work harden.