253MA - Atlas Steels

Grade Data Sheet253MAUNS S30815Atlas 253MA is 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 atmospheres.253MA® 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 phaseprecipitation.The austenitic structure gives this gradeexcellent toughness, even down to cryogenictemperatures.nickel content are preferred if the atmosphereis reducing.Sulphidation - good resistance to sulphurbearinggases in an oxidising atmosphere, evenif only traces of oxygen are present. Reducinggases prevent the protective oxide forming.253MA has high strength at elevatedtemperatures so is often used for structuraland pressure-containing applications attemperatures above about 500°C and up toabout 900°C.253MA will become sensitised in thetemperature range of 425-860°C; this is not aproblem for high temperature applications, butwill result in reduced aqueous corrosionresistance.Heat TreatmentSolution Treatment (Annealing)Heat to 1050-1150°C and cool rapidly. It isrecommended that the material be solutiontreated after 10-20% cold work to achievemaximum creep strength in service.Corrosion ResistanceAlthough not designed for aqueous corrosionresistance, the high chromium and nitrogencontents give the grade a pitting resistanceapproximating that of 316. 253MA doeshowever have a high carbon content so ishighly susceptible to sensitisation; this is likelyto reduce aqueous corrosion resistance afterhigh temperature service or fabrication.Consult Atlas Technical Assistance for specificenvironmental recommendations.Heat ResistanceOxidation - excellent resistance to air, attemperatures up to 1100°C. At hightemperatures 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 noncyclingconditions.Carburisation - Under oxidising conditions thisgrade can perform well, but alloys with higherRevised May 2008 Page 1 of 2www.atlassteels.com.auThis grade cannot be hardened by thermaltreatment.WeldingExcellent weldability by all standard fusionmethods. AS 1554.6 pre-qualifies welding ofS30815 with matching Grade 22.12HT rods orelectrodes. Grade 309 fillers can be used iflower creep strength can be tolerated. Pureargon shielding gas should be used.MachiningAs for other austenitic stainless steels, themachining requires sharp tools, slow speedsand heavy feeds.Typical 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 hangers.

Grade Data Sheet253MAUNS S30815Specified PropertiesThese properties are specified for flat rolled product (plate, sheet and coil) as Grade S30815 inASTM A240/A240M. Similar but not necessarily identical properties are specified for S30815 inother products such as pipe and bar in their respective specifications, and for Grade 1.4835 inspecifications such as EN 10095.Composition Specification (%)Grade C Mn Si P S Cr Ni N CeS30815Grademin.max.0.050.10-0.801.402.00-0.040-0.03020.022.010.012.00.140.20Mechanical Property Specification (single values are minima except as noted)TensileStrength(MPa)minYield Strength0.2% Proof(MPa)minElongation(% in50mm)minRockwellB (HR B)maxHardnessBrinell(HB)maxS30815 600 310 40 95 217Physical PropertiesGradeDensity(kg/m3)ElasticModulus(GPa)Mean Coefficient of ThermalExpansion0-100°C(m/m/°C)0-600°C(m/m/°C)(typical values in the annealed condition)Thermal SpecificConductivity Heat0-1000°C(m/m/°C)at 20°C(W/m.K)at 800°C(W/m.K)0-100°C( J/kg.K)0.030.08ElectricalResistivityS30815 7800 200 17.0 18.5 19.5 15.0 25.5 500 850Grade Specification ComparisonGradeUNSEuronormNo No NameSwedishSS(n.m)JapaneseS30815 S30815 1.4835 X9CrNiSiNCe21-11-2 2368 -These comparisons are approximate only. The list is intended as a comparison of functionally similarmaterials not as a schedule of contractual equivalents. If exact equivalents are needed original specificationsmust be consulted.Possible Alternative GradesGrade Why it might be chosen instead of S30815310 Carburising atmospheres require a higher nickel content304H Lower cost alternative, with lower creep strength, for use up to about 800°C321H Lower cost alternative, with lower creep strength, for use up to about 800°CNickelAlloysCarburising atmospheres or temperatures above the 1100 - 1150°C maximum ofS30815.JISLimitation of LiabilityThe information contained in this datasheet is not an exhaustive statement of all relevant information. 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.Revised May 2008 Page 2 of 2www.atlassteels.com.au