Duplex Steel Pipe Fittings for Structure Pipe
Tel : +86-531-67803178
Whatsapp : +86 18963454069
Email : alice@cndrmetal.com

For our full product, please contact us

CONTACT US

Duplex stainless steel tube has good welding performance, compared with ferritic stainless steel and austenitic stainless steel, it is not like the welding heat affected zone of ferritic stainless steel, because of the severe coarsing grain and the plastic toughness is greatly reduced, nor like austenitic stainless steel, is more sensitive to welding hot crack.


Because of its special advantages, duplex stainless steel is widely used in petrochemical equipment, seawater and wastewater treatment equipment, oil and gas pipelines, papermaking machinery and other industrial fields. In recent years, it has also been studied in the field of bridge bearing structure, with good prospects for development.


Duplex stainless steel is in its solid quenching structure of ferritic phase and austenite phase accounted for half, generally the minimum phase content may be up to 30%.

Steel grade

C≤

Mn≤

Si≤

S≤

P≤

Cr≤

Ni

Mo

Cu≤

N

S32750(SAF2507)

00Cr25Ni7Mo4N

0.03

1.20

0.8

0.020

0.035

24.0/26.0

6.0/8.0

3.0/5.0

0.50

0.24/0.32

S31803(SAF2205)

00Cr22Ni5Mo3N

0.03

2.00

1.0

0.020

0.030

21.0/23.0

4.50/6.50

2.50/3.5


0.08/0.20

S31500(3RE60)

00Cr18Ni5Mo3Siz

0.03

1.2/2.0

1.4/2.0

0.030

0.030

18.0/19.0

4.25/5.25

2.50/3.0


0.05/0.10


Steel grade

σb(Mpa)≥

σs(Mpa)≥

δ(%)≥

hardness

brinell(HB)rockwell(HRC)

S32750(SAF2507)

00Cr25Ni7Mo4N

800

550

15

310

32

S31803(SAF2205)

00Cr22Ni5Mo3N

620

450

25

290

30.5

S31500(3RE60)

00Cr18Ni5Mo3Siz

630

440

30

290

30.5


展示.jpg


Compared with austenitic stainless steel, the advantages of duplex stainless steel

(1) the yield strength is more than twice as high as ordinary austenitic stainless steel, and it has enough plastic toughness required for molding. The wall thickness of tanks or pressure vessels made of duplex stainless steel is 30-50% less than that of commonly used austenite, which is beneficial to reduce costs.


(2) with excellent stress corrosion cracking ability, even the lowest alloy content of duplex stainless steel has higher stress corrosion cracking ability than austenitic stainless steel, especially in the environment containing chloride ions. Stress corrosion is a difficult problem for ordinary austenitic stainless steel.


(3) in many media the most commonly used 2205 duplex stainless steel corrosion resistance is better than ordinary 316L austenitic stainless steel, and super duplex stainless steel has high corrosion resistance, and some media, such as acetic acid, formic acid and so on can even replace high alloy austenitic stainless steel, and corrosion resistant alloy.


(4) has good local corrosion resistance, compared with the alloy content of austenitic stainless steel, its wear corrosion and fatigue corrosion performance is better than austenitic stainless steel.


(5) the linear expansion coefficient is lower than austenitic stainless steel, and close to carbon steel, suitable for connection with carbon steel, has important engineering significance, such as the production of composite plate or lining.


(6) regardless of dynamic or static load conditions, than austenitic stainless steel has higher energy absorption capacity, which for the structural parts to cope with emergencies such as collision, explosion, etc., duplex stainless steel has obvious advantages, has practical application value.


Compared with austenitic stainless steel, duplex stainless steel is weak

(1) the universality and versatility of the application is not as good as austenitic stainless steel, such as its use temperature must be controlled below 250℃.


(2) its plastic toughness is lower than austenitic stainless steel, cold, hot processing technology and molding performance is inferior to austenitic stainless steel.


(3) There is a medium-temperature brittle zone, so the process system of heat treatment and welding needs to be strictly controlled to avoid the appearance of harmful phase and damage performance.


Folding has advantages over ferritic stainless steel, duplex stainless steel

(1) the comprehensive mechanical properties are better than ferritic stainless steel, especially the plastic toughness, not as sensitive to brittleness as ferritic stainless steel.


(2) In addition to stress corrosion resistance, other local corrosion resistance is better than ferritic stainless steel.


(3) Cold processing properties and cold forming properties are far better than ferritic stainless steel.


(4) welding performance is far better than ferritic stainless steel, general welding without preheating, welding without heat treatment.


(5) the application range is wider than ferritic stainless steel.


Compared with ferritic stainless steel, duplex stainless steel is weak

Alloy element content is high, the price is relatively high, general ferrite does not contain nickel.


Product Testing:

检测.jpg


Factory Display:

工厂.jpg


Submit