Made up of chromium-nickel, alloys 309 and 309H are type of stainless steel that is most widely used under high temperature processes. The presence of chromium and nickel in higher concentrations makes them excellent corrosion resistant alloys, also good heat resistant. These alloys hold their strengths in both normal and increased temperatures. The only aspect that differentiates them is the presence of carbon in different ratios. Alloy 309S contains relatively less percentage of carbon and this allows it to control carbide precipitation and provides it with amazing welding properties.
Uses of Alloy 309 and 309S
• In the process of heating different elements
• In the making of aircrafts and jet engines
• Heat exchangers
• In Kiln liners
• Chemical processes
• Refinery apparatus
• Auto exhaust parts
• To carburize annealing products
• In equipment used to control sulfite liquor
Characteristics of SS 309 and SS 309H
• High temperature oxidation resistant
• Maintains strength in higher temperatures
Fine resistance to creep deformation and environmental attacks