Duplex Stainless Steel S31803 Pipes for Heat Exchangers

● UNS S31803 is a ferritic-austenitic stainless steel that combines many of the beneficial properties of ferritic and austenitic steels. Due to the high content of chromium and molybdenum, the steel has very good pitting and uniform resistance to stress corrosion cracking corrosion as well as high mechanical strength.

● UNS S31803 has good weldability and can be welded using most welding techniques for stainless steel. Due to the compositional balance, when welded correctly, the HAZ contains enough austenite to avoid the risk of localized corrosion.

● The chemical composition of UNS S31803 is balanced to obtain a microstructure containing approximately equal amounts of ferrite and austenite.

UNS S31803 Chemical Composition

UNS S31803 production standard
● ASTM A790, A815, A182
● ASME SA790, SA815, SA182
 
UNS S31803 Design Features

● High strength.
● Compared with austenitic steel, it has low thermal expansion and high thermal conductivity.
● High resistance to stress corrosion cracking, corrosion fatigue and erosion.
● High uniform corrosion resistance.
● High resistance to pitting and crevice corrosion.
● Good resistance to sulfide stress corrosion cracking.
 
UNS S31803 Typical Applications

● Heat exchangers, pipes and piping for the production and processing of gases and oils
● Heat exchangers and piping in salinization plants
● Pressure vessels, pipes, tanks and heat exchangers for processing and transporting various chemicals
● Pressure Vessels, Tanks and Pipelines in Process Industries Handling Chlorides
● Rotors, fans, shafts and rollers with high corrosion fatigue strength are available
● Chemical Tankers, Piping and Welding Consumables
 
UNS S31803 Tensile Requirements

● The tensile strength is 65 KSI and the yield strength is 90 KSI.
● This is equivalent to 488.175 MPa and 620.55 MPa.