ASTM A182 Duplex Stainless Steel Flanges with high resistance to pitting

It is widely used in offshore oil and gas exploration/production and in heat exchangers in petrochemical/chemical processing.

Higher chromium, molybdenum and nitrogen content results in a Pitting Resistance Equivalent Number (PREN) > 40, providing superior pitting and crevice corrosion capabilities to austenitic and duplex stainless steels in virtually all corrosive media, and critical pitting temperature Above 50¡ãC .

Super Duplex is composed of 24% to 26% chromium, 6% to 8% nickel, 3% molybdenum and 1.2% manganese, with the remainder being iron. Trace amounts of carbon, phosphorus, sulfur, silicon, nitrogen, and copper were also found in Super Duplex.

Duplex steel flange also offers Good weldability and workability, High energy absorption and Low thermal expansion.

The flange is second most used joining method after selding. Flanges are used when joints need dismantling. It provides flexibility for maintenance. Flange connects the pipe with various equipment and valves. Breakup flanges are added in the pipeline system if regular maintenance in required during plant operation.
A flanged joint is composed of three separate and independent although interrdlated components; the flanges, the gaskets, and the bolting; which are assembled by yet another influence, the fitter. Special controls are required in the selection and application of all there elements to attain a joint, which has acceptable leak tightness.
A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength (as the flange of an iron beam such as an I-beam or a T-beam); for easy attachment/transfer of contact force with another object (as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera); or for stabilizing and guiding the movements of a machine or its parts (as the inside flange of a rail car or tram wheel, which keep the wheels from running off the rails). The term “flange” is also used for a kind of tool used to form flanges.

Another advantage of grade 304 stainless steel bar over grade 303 is that it is slightly harder and has better corrosion resistance. Because of this, grade 304 stainless steel bar is used in large quantities in the manufacture of fasteners and fixtures such as nuts, bolts, washers, clips, fittings and clamps. Products made from grade 304 stainless steel in the fastener industry are often referred to as “A2”.

Duplex 2205 was tested under reverse bending stress at room temperature compared to SS316. The results show that Duplex 2205 has approximately twice the fatigue limit/yield strength.

ASTM A182 F51 flanges refer to pipe flanges made from the forged duplex stainless steel grade UNS S31803 for use in pressure systems.

The material for UNS S32760 Stud Bolts is about 10% lighter when compared to grade 316 stainless steel. The Stud Bolt S32760 demonstrates high performance at cryogenic temperature settings as well. Which means that the ASTM A1082 UNS S32760 has good sub-zero notch ductility properties down to a temperature of minus 50¡ãC.

The chemistry of this steel ensures better performance with higher mechanical properties in comparison to austenitic stainless steel pipes.

The steel has excellent resistance to chloride stress corrosion cracking, high thermal conductivity, and a low coefficient of thermal expansion.

Grade UNS S31803 is termed as a duplex class due to its mixed Austenitic-ferritic microstructure. Duplex stainless steel alloys have an equal proportion of both austenite and ferrite, which is why Duplex Steel Fittings exhibit properties prominent to both classes.

A butt weld pipe fitting is designed to be welded on site at its end(s) to connect pipe(s) together and allow change in direction or pipe diameter, or branching or ending.

This fitting then becomes part of a system for transporting fluids (oil, gas, steam, chemicals, …) in a safe and efficient manner, over short or long distances.

ASTM A182 F51 equates to UNS S31803. This was the original caption for a 22% Cr duplex stainless steel.

The duplex material contains bot the austenitic and ferrite structures in the metallurgy of the material. These properties bring the material the best of both ferritic and austenitic steel types. The pipes could be hot rolled or cold drawn. The hot rolled ones are stronger and the cold drawn ones are seamless and accurate in dimensions. The Duplex Seamless Pipe is used in applications with high precision requirements.
Type “Seamless Pipe
Seamless Tube
Welded Pipe
Welded Tube
SAW LSAW ERW EFW
Beveled End, Plain End”
Size “OD: 1/2″” ~48″”
Thickness: SCH5~SCHXXS
Length :As per your requirement.”

Super Duplex S32760 Bar proves to be an excellent replacement for austenitic grades in marine environments. Super Duplex S32760 round bar (ASTM A276/ ASTM A479) exhibits good heat resistance up to 300¡ã.

Although when the 2205 duplex stainless tubing material has been exposed to temperatures above 572¡ãF, even when the exposure is for a short period of time, the duplex 2205 seamless tube is subject to embrittlement.
Type “Seamless Pipe
Seamless Tube
Welded Pipe
Welded Tube
SAW LSAW ERW EFW
Beveled End, Plain End”
Size “OD: 1/2″” ~48″”
Thickness: SCH5~SCHXXS
Length :As per your requirement.”

The standard austenitic steels like 304 (1.4301) and ferritic steels like 430 are relatively easy to make and to fabricate. As their names imply, they consist mainly of one phase, austenite or ferrite. Although these types are fine for a wide range of applications, there are some important technical weaknesses in both types.

S32760 is a super duplex stainless steel with a ferritic-austenitic microstructure.

The flanges could also be manufactured as screwed, threaded or forged types. The forged flanges are made from a single piece of raw material. These are also called the cast flanges.

2507 has Combination of properties given by austenitic and ferritic structure, and Good weldability and workability.

2205 dual-phase steel fasteners have some excellenut mechanical properties, which may be due to the balanced austenitic and ferritic microstructures in the alloy.

Known for its high impact strength, UNS S32760 exhibits no ductile-brittle transition, but only a slight decrease in impact energy with decreasing temperature.

Duplex steel sheets are resistant to chloride stress corrosion cracking at 150¡ãC.

The ASTM A790 Duplex 2205 Pipe produced under this specification are intended to be used for those applications where corrosion resistance is a primary concern.

Duplex stainless steel has an array of various benefits such as:
Strength:Duplex stainless steels have approximately double the strength of regular austenitic or ferritic stainless steels.
Toughness and ductility:Duplex stainless steels exceed the toughness and ductility of ferritic grades although they are not as touch as austenitic grades.
Corrosion resistance:As with all stainless steels, corrosion resistance depends mostly on the composition of the stainless steel, with chromium, molybdenum and nitrogen content being the most important. Duplex stainless steels are extremely corrosion resistant and even in chloride and sulphide environments, duplex stainless steels exhibit very high resistance to stress corrosion cracking (SCC). SCC is a type of corrosion that takes place when a particular set of factors are present: Tensile stress, corrosive environment and a sufficiently high temperature.
Seamless Tube
Welded Pipe
Welded Tube
SAW LSAW ERW EFW
Beveled End, Plain End”
Size “OD: 1/2″” ~48″”
Thickness: SCH5~SCHXXS
Length :As per your requirement.”

This grade, with a tighter specification, is captioned as F60, equating to UNS S32205. Consequently, S32205 can be dual-certified as S31803 but not vice-versa.

Super Duplex UNS S32750 bar has excellent resistance to stress corrosion cracking in chlorine containing environments. After heating to a solution treatment temperature of 1080¡ãC to 1120¡ãC, quenching is required.

Super Duplex Steel UNS S32760 are dual phase austenitic-ferritic duplex fasteners manufactured from alloy containing chromium, nickel and molybdenum with restricted carbon content and minimum PREN42. Zeron washers have high strength, resistance to pitting, stress corrosion cracking, erosion and corrosion fatigue, crevice corrosion resistance.

The origin of Duplex steels can be traced back to the 1920s, with the first cast being made in Sweden in 1930. However, the popularity of using duplex only started to rise around 30 years ago when steelmaking technology became more advanced. The two types of metals used to make Duplex ¨C austenitic and ferritic ¨C are both fit for purpose in many types of scenarios but they both have weaknesses that prevent them from being used more widely.
Type “Seamless Pipe
Seamless Tube
Welded Pipe
Welded Tube
SAW LSAW ERW EFW
Beveled End, Plain End”
Size “OD: 1/2″” ~48″”
Thickness: SCH5~SCHXXS
Length :As per your requirement.”

Compared with ferritic stainless steel and austenitic stainless steel, duplex stainless steel pipe has good welding performance. It is neither like the welding heat affected zone of ferritic stainless steel, because of the grain coarsening, the plastic toughness is greatly reduced, nor like austenitic stainless steel, it is more sensitive to welding hot cracks.
Type “Seamless Pipe
Seamless Tube
Welded Pipe
Welded Tube
SAW LSAW ERW EFW
Beveled End, Plain End”
Size “OD: 1/2″” ~48″”
Thickness: SCH5~SCHXXS
Length :As per your requirement.”

Heated from 1050¡ãC to 1150¡ãC and water quenched, this treatment of duplex steel UNS S31803 nuts ensures that all carbides are dissolved.