ASTM A240 UNS S31803

ASTM A240 UNS S31803 Plate is a duplex grade with a ferritic-austenitic microstructure which enables combining improved resistance to pitting, stress corrosion, high strength, crevice corrosion and cracking.

SA 240 S31803 Plate resists sulfide stress corrosion and chloride environments. It consists of around 40-50% ferrite in the annealed condition. Its high temperature strength are similar to stainless steel 430 in the range of 950~1150°C. However it shows rapid increase in the strength below 900°C. Cold workability is required as proof stress is high and elongation is low as compared to stainless steel 304.It is useful in application of oil & gas, pressure vessels, hydro power, pulp & paper, chemical tankers and structural components. It is not recommended to be used at temperatures above 300°C due to embrittlement.

ASTM A240 UNS S32205 Sheet has high strength of the ferritic grades while keeping the corrosion resistance of the austenitic grades. It has combination of good mechanical strength and ductility with moderate to good corrosion resistance in a variety of environments.

SA 240 UNS S32205 Plate is used as a practical solution to chloride-induced stress cracking, which is the achilles’ heel of stainless steel. It has magnetic property that can be used to easily differentiate them from common austenitic stainless grades.

As compared to 317L stainless steel ASTM A240 UNS S32205 Sheet and Plate has superior resistance to crevice corrosion and chloride pitting.It has an outstanding corrosion resistance to most concentrations of sulphuric acid and seawater and also resistant to sulphide stress corrosion cracking. It widely attributed to the high levels of chromium present as well as nitrogen and molybdenum.