The main representative grades of duplex stainless steel can be generally divided into four categories:
1. Low alloy type – representative grade: UNS S32304 (23Cr-4Ni-0.1N)
2. Medium alloy type – representative grade: UNS-S31803 (22Cr-5Ni) -3Mo-0.1N)
3. high alloy type – representative grade: UNS S32550 (22Cr-6Ni-3Mo-2Cu-0.2N)
4. super duplex stainless steel type – standard grade: UNS-S32507 (25Cr-7Ni- 3.7Mo-0.3N).
Low-alloy
UNS S32304 contains no molybdenum and can be used in place of AISI304 or 316 for stress corrosion resistance. Medium alloy type: UNS S31803 has corrosion resistance between AISI316L and 6%Mo+N austenitic stainless steel; high alloy type : generally contains 25% Cr, also contains molybdenum nitrogen, and some also contain copper wall iron and tungsten, such steel has higher corrosion resistance than 22% Cr duplex stainless steel; super duplex stainless steel: contains high molybdenum and nitrogen, Some also contain tungsten and copper, also suitable for harsh media conditions cv548, with good corrosion resistance and mechanical properties, comparable to super austenitic stainless steel.
Post time: Mar-15-2019
