STAINLESS STEEL OVERVIEW: TUTORIAL
Fourth Branch
Duplex Stainless Steels
When the chromium content is high (18 to 26%) and the nickel content is low
(4 to 7%), the resulting structure is called Duplex. In addition most grades
contain 2 to 3% molybdenum. This results in a structure that is a combination
of both Ferritic and Austenitic (hence the name Duplex), and have the following
characteristics:
- High resistance to stress corrosion cracking
- Increased resistance to chloride ion attack
- Very weldable
- Have higher tensile and yield strengths than Ausenitic or Ferritic stainless steels
Common Uses:
- Sea water applications
- Heat exchangers
- Desalination plants
- Food pickling plants
Common Grades:
- Metallurgical structure - Duplex
- Grade: 2205
- Unified Numbering System UNS: S31803