Heat Resistance:
Oxidation - excellent resistance to air, at temperatures up to 1100°C. At high temperatures the steel quickly forms a thin, highly adherent and elastic oxide. This oxide gives good protection even under cyclic conditions, much better than is the case for Grade 310. Best resistance is under non- cycling conditions.
Carburisation - Under oxidising conditions this grade can perform well, but alloys with higher nickel content are preferred if the atmosphere is reducing.
Sulphidation - good resistance to sulphur- bearing gases in an oxidising atmosphere, even if only traces of oxygen are present. Reducing gases prevent the protective oxide forming.
253MA has high strength at elevated temperatures so is often used for structural and pressure-containing applications at temperatures above about 500°C and up to about 900°C.
253MA will become sensitised in the temperature range of 425-860°C; this is not a problem for high temperature applications, but will result in reduced aqueous corrosion resistance.
Heat Treatment 253 MA / S30815 / 1.4835 Seamless Stainless Steel Tube:
Solution Treatment (Annealing)
Heat to 1050-1150°C and cool rapidly. It is recommended that the material be solution treated after 10-20% cold work to achieve maximum creep strength in service.
This grade cannot be hardened by thermal treatment.
Welding
Excellent weldability by all standard fusion methods. AS 1554.6 pre-qualifies welding of S30815 with matching Grade 22.12HT rods or electrodes. Grade 309 fillers can be used if lower creep strength can be tolerated. Pure argon shielding gas should be used.
Machining
As for other austenitic stainless steels, the machining requires sharp tools, slow speeds and heavy feeds.
Typical Applications of 253 MA / S30815 / 1.4835 Seamless Stainless Steel Tube:
Furnace components including burners, retorts, conveyor belts, fans, jigs and baskets, rollers, walking beams, radiant tubes, electric heater elements, refractory anchors, hoods, flues, grates, expansion bellows. Petrochemical and refinery tube hangers.
