Atlas Grade datasheet 253MA rev May 2008 July 2010

1 Grade Data Sheet253 MAUNS S30815 Revised May 2008 Page 1 of 253 MAis a Grade combining excellentservice properties at high temperatures withease of fabrication. It resists oxidation attemperatures up to 1150 C and can providesuperior service to Grade 310 in carbon,nitrogen and sulphur containing is a trademark owned by OutokumpuStainless AB. The standard Grade designationcovering this Grade is UNS S30815. Other millsproduce grades compliant with UNS S30815,including Sirius S15 . 253MA contains a fairly low nickel content,which gives it some advantage in reducingsulphide atmospheres when compared to highnickel alloys and Grade 310. The inclusion ofhigh chromium, silicon, nitrogen and ceriumcontents gives the steel good oxide stability,high elevated temperature (creep) strengthand excellent resistance to sigma austenitic structure gives this gradeexcellent toughness, even down to ResistanceAlthough not designed for aqueous corrosionresistance, the high chromium and nitrogencontents give the Grade a pitting resistanceapproximating that of 316.

2 253MA doeshowever have a high carbon content so ishighly susceptible to sensitisation; this is likelyto reduce aqueous corrosion resistance afterhigh temperature service or Atlas Technical Assistance for specificenvironmental ResistanceOxidation - excellent resistance to air, attemperaturesupto1100 the steel quickly forms a thin,highly adherent and elastic oxide. This oxidegives good protection even under cyclicconditions, much better than is the case forGrade 310. Best resistance is under non-cycling - Under oxidising conditions thisgrade can perform well, but alloys with highernickel content are preferred if the atmosphereis - good resistance to sulphur-bearing gases in an oxidising atmosphere, evenif only traces of oxygen are present. Reducinggases prevent the protective oxide so is often used for structuralandpressure-containingapplicat ionsattemperatures above about 500 C and up toabout 900 range of 425-860 C; this is not aproblem for high temperature applications, butwill result in reduced aqueous TreatmentSolution Treatment (Annealing)Heat to 1050-1150 C and cool rapidly.

3 It isrecommended that the material be solutiontreated after 10-20% cold work to achievemaximum creep strength in Grade cannot be hardened by weldability by all standard fusionmethods. AS pre-qualifies welding ofS30815 with matching Grade rods orelectrodes. Grade 309 fillers can be used iflower creep strength can be tolerated. Pureargon shielding gas should be for other austenitic stainless steels, themachining requires sharp tools, slow speedsand heavy ApplicationsFurnace components including burners, retorts,conveyor belts, fans, jigs and baskets, rollers,walking beams, radiant tubes, electric heaterelements, refractory anchors, hoods, flues,grates, expansion bellows. Petrochemical andrefinery tube Data Sheet253 MAUNS S30815 Revised May 2008 Page 2 of PropertiesThese properties are specified for flat rolled product (plate, sheet and coil) as Grade S30815 inASTM A240/A240M.

4 Similar but not necessarily identical properties are specified for S30815 inother products such as pipe and bar in their respective specifications, and for Grade inspecifications such as EN Specification (%) Property Specification(single values are minima except as noted)HardnessGradeTensileStrength(MPa)m inYield Proof(MPa)minElongation(% in50mm)minRockwellB (HR B)maxBrinell(HB)maxS308156003104095217 Physical Properties(typical values in the annealed condition)Mean Coefficient of ThermalExpansionThermalConductivityGrade Density(kg/m3)ElasticModulus(GPa)0-100 C( m/m/ C)0-600 C( m/m/ C)0-1000 C( m/m/ C)at 20 C( )at 800 C( )SpecificHeat0-100 C( )ElectricalResistivity(n .m) Specification comparisons are approximate only. The list is intended as a comparison of functionally similarmaterialsnotas a schedule of contractual equivalents. If exact equivalents are needed original specificationsmust be Alternative GradesGradeWhy it might be chosen instead of S30815310 Carburising atmospheres require a higher nickel content304 HLower cost alternative, with lower creep strength, for use up to about 800 C321 HLower cost alternative, with lower creep strength, for use up to about 800 CNickelAlloysCarburising atmospheres or temperatures above the 1100 - 1150 C maximum of LiabilityThe information contained in this datasheet is not an exhaustive statement of all relevant information.

5 It is a generalguide for customers to the products and services available from Atlas Steels and no representation is made or warrantygiven in relation to this document or the products or processes it describes.