253MA Forgings, UNS S30815 / EN 1.4835 / ASTM A182 F45

253MA forged products we manufacture

Jiangyin Jiangnan Metal produces 253MA open-die forgings and seamless rolled rings to customer drawings: forged rings, seamless rolled rings, forged flanges, round bars, discs and disks, bushings and sleeves, shafts and spindles, forged tubes and hollow bars, tube sheets, forged pipe, valve bodies and valve seat rings, nozzles, blocks and rolls.

Confirm the exact envelope with our engineers before placing an order.

253MA equivalent designations

Cross-references are functional comparisons and not contractual equivalents. Where an exact equivalent is required, consult the original specification. 253 MA is a trademark owned by Outokumpu OY. Jiangyin Jiangnan Metal is not affiliated with, endorsed by or licensed by Outokumpu and supplies the generic grade UNS S30815 / EN 1.4835.

253MA chemical composition, ASTM A182 grade F45

Cerium is added as mischmetal, so other rare-earth metals accompany the cerium. Nominal mill analysis for the grade is about 0.08% C, 1.6% Si, 21% Cr, 11% Ni, 0.17% N and 0.05% Ce. Flat-rolled product to ASTM A240 permits a lower silicon minimum of 1.10% than the A182 F45 forging grade, so silicon should be stated explicitly when ordering forgings.

Our 253MA is melted by EAF + VOD, with ESR remelting available on request for improved cleanliness and ultrasonic quality.

253MA mechanical properties

Room temperature, minimum values

Typical mill-annealed tensile strength for the grade falls between 650 and 850 MPa (94 to 123 ksi), with 1.0% proof strength of 350 MPa (51 ksi) minimum and hardness around 190 HV. The austenitic structure gives good toughness down to cryogenic temperatures.

Elevated-temperature strength

Creep rupture strength

Above about 550 C (1020 F), design stress for 253MA is governed by creep rupture strength rather than by Rp0.2 proof strength.

Creep values are published grade data given for information. They do not replace the allowable stresses of the governing design code, and Jiangyin Jiangnan Metal does not carry out pressure-vessel design.

253MA physical properties

Heat and corrosion resistance

Oxidation

253MA forms a thin, adherent and elastic oxide that stays protective under cyclic heating, an effect produced by the combined silicon and rare-earth additions. Maximum recommended service temperature in air is about 1150 C (2100 F). Published isothermal oxidation testing at 1150 C gives roughly 0.3 mm/year after 100 h and about 0.2 mm/year after 1000 h, while cyclic oxidation at the same temperature stays below about 1.1 mm/year. In severe cyclic testing 253MA outperforms both ASTM TP310 and EN 1.4828 (TP309).

Carburisation

Carburisation resistance is good in oxidising conditions, because the chromium, silicon and rare-earth content readily forms a protective oxide. Published testing in a methane-argon mixture shows less carburisation than TP310 and Alloy 800H. Where the atmosphere is strongly reducing, higher-nickel alloys are preferred.

Sulphidation and other atmospheres

Resistance to sulphur-bearing gases is good provided that at least traces of oxygen are present to maintain the oxide. In nitrogen atmospheres with very little or no oxygen, 253MA is inferior to Alloy 800H and 25Cr/20Ni steels, and the grade is not recommended for muffle tubes operating in cracked ammonia. The steel shows good resistance to cyanide and neutral salt melts and to molten metals such as lead.

Structural stability

Chromium is moderate and nitrogen is deliberately added, so 253MA is less prone to sigma-phase embrittlement than 25Cr/20Ni steels.

Wet corrosion

The high chromium and nitrogen give pitting resistance roughly comparable with 316, and chloride stress-corrosion cracking resistance slightly better than 304. The grade nevertheless carries 0.05 to 0.10% carbon and sensitises in the 425 to 860 C range, so aqueous corrosion resistance after service exposure or welding is reduced. 253MA should not be selected as a wet-corrosion alloy.

Where 253MA forgings are used

253MA combines high creep strength with cyclic oxidation resistance, so it is specified where 18/8 austenitics lack oxidation and carburisation resistance, and where straight chromium steels lack creep strength and structural stability. It can substitute for 25Cr/20Ni steels and Alloy 800H, and in some cases for Alloy 600. Typical forged applications:

• Industrial furnaces. Forged burner components, retorts, radiant tubes, furnace rollers, walking beams, fans, hoods, flues, grates, jigs, baskets, refractory anchors and expansion bellows rings.
• Petrochemical and refining. Tube hangers and supports, forged flanges and tube sheets for waste-heat recovery, convection tube components in ethylene cracking, styrene reactor and EDC cracking hardware.
• Metallurgical plant. Recuperator components, pulverised-coal injection lance parts for blast furnaces, continuous wire annealing furnace parts.
• Power and incineration. Fluidised-bed combustion components, sludge incineration furnace parts, carbon-black process gas cooler and air heater parts, air preheater components in sulphuric acid gas converters.
• Cement, glass and heat treatment. Forged rolls, shafts, discs, bushings and sleeves running hot and cycling.
• High-temperature valves. Forged bodies, blocks, seat rings and stems for gate, globe, ball, check and plug valves in hot gas service.

Forging, heat treatment and fabrication

Hot working

Our shop practice is to forge 253MA from a soak temperature near 1150 C, with finish forging kept above roughly 900 C, followed by solution annealing. Published guidance for hot bending of the grade is 1100 to 850 C (2050 to 1560 F), also followed by solution annealing.

Solution annealing

Solution anneal at 1050 to 1150 C (1920 to 2100 F) for 5 to 20 minutes, then cool rapidly in air or water. Stress relieving, where required, is carried out at 850 to 950 C for 10 to 15 minutes with air cooling. Material that has received 10 to 20% cold work should be solution treated to restore maximum creep strength in service. 253MA cannot be hardened by thermal treatment.

Welding

Weldability is good by all standard fusion processes, with TIG/GTAW the first choice and MMA/SMAW also suitable. Matching filler is EN ISO 14343-A G 21 10 N, W.-Nr. 1.4829, commonly known as 22.12 HT. EN ISO 3581-A E Z 23 10 N R 12 covers MMA electrodes. Grade 309 fillers are acceptable only where lower creep strength is tolerable. Recommended heat input is below 1.5 kJ/mm with interpass temperature below 150 C, and pure argon shielding should be used.

Machining

As with other austenitic stainless steels, use sharp tooling, slow speeds and heavy feeds. Sulphur is low, so chip breaking is less favourable than in free-machining grades.

Testing, NDT and certification

253MA forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 as required by the order. Available on request: liquid penetrant examination, PMI verification, grain size and intergranular corrosion testing, elevated-temperature tensile testing and impact testing. Certification is issued to EN 10204 type 3.1, or type 3.2 with third-party inspection by BV, SGS, TUV, Lloyd's or a nominated inspector. Forgings can be supplied as SA-182 F45 to ASME Section VIII requirements where the order calls for it. The grade is approved for use in the ASME Boiler and Pressure Vessel Code, Sections I, III and VIII Division 1.

253MA compared with alternative grades

Standards and data sources

Chemical composition and mechanical minima on this page follow ASTM A182 grade F45, UNS S30815. Oxidation, carburisation, creep, physical property, heat-treatment and welding data follow published grade datasheets for 253 MA / S30815 / 1.4835:

• ASTM A182 / A182M grade F45, UNS S30815, chemistry and mechanical requirements: specification summary.
• Alleima 253 MA material datasheet, creep, oxidation, carburisation, physical properties, heat treatment and welding: datasheet.
• Atlas Steels grade datasheet, Stainless Steel Grade 253MA, UNS S30815: datasheet.
• Outokumpu Therma 253 MA product page, service temperature to 1150 C: product page.

Values are given for material selection guidance. They are not a warranty of performance in a specific service, and the purchase specification and design code take precedence.