Stainless pipe fitting,stainless fitting,duplex stainless,31803,32750,32760,we are one of largest sour service stainless fitting supplier according to ISO 10156.
The so-called duplex stainless steel is in its solid quenching organisation in the ferritic phase and austenitic phase each accounted for half, generally the least phase content needs to reach 30%.
Due to the characteristics of the two-phase organisation, through the correct control of the chemical composition and heat treatment process, so that the DSS (Duplex Stainless Steel, referred to as DSS), both ferritic stainless steel and austenitic stainless steel advantages.
Compared with austenitic stainless steel, the advantages of duplex stainless steel are as follows:
(1) yield strength than ordinary austenitic stainless steel is more than twice as high, and has sufficient plastic toughness needed for forming. The use of duplex stainless steel manufacturing tanks or pressure vessels to reduce the wall thickness than the commonly used austenitic 30-50%, which is conducive to cost reduction.
(2) has excellent resistance to stress corrosion rupture, even the lowest alloy-containing duplex stainless steel has a higher resistance to stress corrosion rupture than austenitic stainless steel, especially in the environment containing chloride ions. Stress corrosion is common austenitic stainless steel is difficult to solve the outstanding problems.
(3) in many media in the most common application of 2205 duplex stainless steel corrosion resistance is better than ordinary 316L austenitic stainless steel, and super duplex stainless steel has a very high corrosion resistance, in some media, such as acetic acid, formic acid, etc. and can even replace the high-alloyed austenitic stainless steel, and even corrosion-resistant alloys.
(4) has good resistance to local corrosion, with a comparable alloy content of austenitic stainless steel, its resistance to wear corrosion and fatigue corrosion are better than austenitic stainless steel.
(5)Lower coefficient of linear expansion than austenitic stainless steel, and carbon steel is close, suitable for connection with carbon steel, has important engineering significance, such as the production of composite plates or linings.
(6) Whether in dynamic or static load conditions, than the austenitic stainless steel has a higher energy absorption capacity, which is structural components to cope with sudden accidents such as impact, explosion, etc., duplex stainless steel advantage is obvious, there are practical applications.
Compared with austenitic stainless steel, duplex stainless steel disadvantages are as follows:
(1) The universality and versatility of the application is not as good as austenitic stainless steel, for example, its use temperature must be controlled below 250 degrees Celsius.
(2) Its plastic toughness is lower than austenitic stainless steel, cold, hot working process and moulding performance is not as good as austenitic stainless steel.
(3) The existence of medium temperature brittle zone, need to strictly control the heat treatment and welding process system, in order to avoid the emergence of harmful phases, damage performance.
Compared with ferritic stainless steel, the advantages of duplex stainless steel are as follows:
(1) The comprehensive mechanical properties are better than ferritic stainless steel, especially the plastic toughness, not as sensitive to embrittlement as ferritic stainless steel.
(2) In addition to stress corrosion resistance, other local corrosion resistance is better than ferritic stainless steel.
(3) Cold working process performance and cold forming properties are much better than ferritic stainless steel.
(4) Welding performance is also far better than ferritic stainless steel, generally do not need preheating before welding, no heat treatment after welding.
(5) Wider range of applications than ferritic stainless steel.
Compared with ferritic stainless steel, duplex stainless steel is vulnerable as follows:
High content of alloying elements, the price is relatively high, generally ferritic does not contain nickel.
In summary, can be seen in general terms the use of DSS performance and process performance of the general picture, it is its superior mechanical and corrosion resistance of the overall performance to win the favour of users, has become both weight-saving and investment saving excellent corrosion-resistant engineering materials.
About Our Solutions
[C&N Hongcheng] provides premium duplex stainless products including:
- DSS pipes (2205/2507 grades)
- Custom flanges & fittings
- Technical support services
Benefits of choosing us:
✅ ISO-certified production
✅ 15+ years industry experience
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