253 MA Stainless Steel Data Sheet

GENERAL PROPERTIES

253MA is a grade combining excellent service properties at high temperatures with ease of fabrication. It resists oxidation at temperatures up to 1150°C and can provide superior service to Grade 310 in carbon, nitrogen and sulphur containing atmospheres. 253MA contains fairly low nickel content, which gives it some advantage in reducing sulphide atmospheres when compared to high nickel alloys and to Grade 310. The inclusion of high silicon, nitrogen and cerium contents gives the steel good oxide stability, high elevated temperature strength and excellent resistance to sigma phase precipitation.

The austenitic structure gives this grade excellent toughness, even down to cryogenic temperatures.

RESISTANCE TO CORROSION

Although not designed for aqueous corrosion resistance the high chromium and nitrogen contents give the grade a pitting resistance approximating that of 316. 253MA does however have a high carbon content so is highly susceptible to sensitisation from welding or service exposure.

PHYSICAL PROPERTIES

MECHANICAL PROPERTIES

CHEMICAL PROPERTIES

WELDING

Excellent weldability by all standard fusion methods, using matching filler metals. AS 1554.6 pre-qualifies welding of 253MA with 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.

HEAT TREATMENT

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.