Call today for a free estimate
North America: +1-918-437-5400 • South America: +56-2-2243-9345 • Australia-Asia-NZ: +64-3-545-0445

Call today for a free estimate
North America: +1-918-437-5400
South America: +56-2-2243-9345
Australia-Asia-NZ: +64-3-545-0445

Alloy 309 & 309S Stainless Steel

Heat resistant stainless steel for use in high temperature service.

Applications

Alloy 309 and Alloy 309S are heat resistant varieties of stainless steel used in high temperature service. You can find 309 and 309S steel pipe and products in incinerators, furnaces, burners, kilns, annealing and carburizing boxes, combustion chambers, salt pots, thermo wells, gas turbines, retorts, flairs and equipment to handle sulfite liquor.

Properties

Alloy 309 and 309S is best known for high temperature service. This alloy works well up to 2000 °F, especially if oxidation resistance is required. 309 and 310 stainless steel are premier high temperature performers among the common stainless grades available from our stock. High nickel and chromium content and a coarse grain structure result in:

  • Improved resistance to cyclic oxidation
  • Increased resistance to sulfidation
  • Better high temperature strength
  • Improved resistance to intergranular corrosion

309S (UNS S30908) stainless steel is the low carbon version of the alloy. It is utilized for ease of fabrication.

309H (UNS S30909) is a high carbon modification developed for enhanced creep resistance. It most instances the grain size and carbon content of the plate can meet both the 309S and 309H requirements. When heated between 1202 – 1742°F (650 – 950°C) the alloy is subject to sigma phase precipitation. A solution annealing treatment at 2012 – 2102°F (1100 – 1150°C) will restore a degree of toughness. Alloy 309 can be easily welded and processed by standard shop fabrication practices.

Specifications

Type Sizes Schedules ASTM Standards
Bar A276, A479
Butt Weld Fittings 1/2″ thru 12″ Sch 10, 40, 80, 160 & XXH A403
Forgings A182
Pipe Welded & Seamless 1/4″ thru 16″ Sch 10, 40, 80, 160 & XXH A312
Tube, Welded A249
Tube, Seamless A213
Plate A240
Flange & Pressure Fittings All Descriptions A182