Alleima® 253 MA Tube and pipe, seamless

Datasheet updated

2022-06-29 14:44
(supersedes all previous editions)

Alleima® 253 MA is an austenitic chromium-nickel steel alloyed with nitrogen and rare earth metals. The grade is characterized by:

  • High creep strength
  • Very good resistance to isothermal and, particularly, cyclic oxidation
  • Good structural stability at high temperatures
  • Good weldability
  • Maximum operating temperature is approx. 1150°C (2100°F)

Trademark information: 253 MA is a trademark owned by Outokumpu OY

Standards

  • UNS: S30815
  • EN Number: 1.4835
  • W.Nr.: (1.4893)*/(1.4828 mod.)*
  • SS: 2368*

Product standards

  • ASTM A213, A312
  • EN 10297-2
  • SS 14 23 68*

* Obsolete. Replaced by EN.

Approvals

Approved for use in ASME Boiler and Pressure Vessel Code, Section I, III and VIII, Div. 1 (SA-182, SA-213, SA-240, SA-249 SA-312 and SA-479).

Chemical composition (nominal)

Chemical composition (nominal) %
C Si Mn P S Cr Ni N Ce*
0.08 1.6 ≤0.8 ≤0.040 ≤0.030 21 11 0.17 0.05

* To cerium should be added the quantity of other rare earth metals, since the the additive takes the form of misch metal containing about 50% Ce.

Chemical composition (nominal) %

C Si Mn
P
S
Cr Ni N Ce*
0.08 1.6 ≤0.8 ≤0.040 ≤0.030 21 11 0.17 0.05

* To cerium should be added the quantity of other rare earth metals, since the the additive takes the form of misch metal containing about 50% Ce.

Applications

The high creep strength of Alleima 253 MA, coupled with its excellent oxidation resistance and its good resistance to carburization in constantly carburizing gas, makes it a very suitable material for end uses in which 18/8 steels lack the necessary resistance to oxidation and carburization.

Alleima 253 MA is often preferred instead of stainless chromium steels which have insufficient creep strength and structural stability. Furthermore, Alleima 253 MA can very well take the place of higher alloyed materials such as 25Cr/20Ni steels and Alloy 800H, or even Alloy 600 in certain cases.

Alleima 253 MA has come to be used extensively in the metallurgical, petrochemical and power industries. Typical applications are:

  • Tubes in waste heat recovery systems in the metallurgical industry, e.g. recuperators
  • Tubes in heat treatment furnaces, e.g. radiation tubes, thermocouple protection tubes, burner components, furnace rollers
  • Tubes for injection of pulverized coal in blast furnaces
  • Tubing for fluidized-bed combustion plants
  • Furnace tubes for mud incineration plants
  • Tubes for carbon black process gas coolers/air heaters
  • Tubes for the glass and cement industries
  • Styrene reactor tubes
  • EDC cracking tubes
  • Convection tubes in ethylene cracking
  • Air preheater tubes in sulphuric acid gas converters
  • Muffle tubes in continuous wire annealing furnaces

Trademark information: 253 MA is a trademark owned by Outokumpu OY

Corrosion resistance

Air

Alleima 253 MA has very high resistance to oxidation, especially at cyclically varying temperatures. See Figs. 3 and 4. The service temperature in air should not exceed about 1150°C (2100°F).

Isothermal oxidation at 1150°C (2100°F) for 100 h results in a corrosion rate of about 0.3 mm/year (13 mpy), and exposure at the same temperature for 1000 h causes about 0.2 mm/year (9 mpy).

Cyclic oxidation at 1150°C (2100oF) for 5 x 24 h, with cooling to room temperature every 24 hours gives a corrosion rate of less than 1.1 mm/year (43 mpy), which is only marginally greater than the corrosion rate at 1000°C (1830°F).

Cyclic oxidation testing for 1000 h (15 minutes at the testing temperature and 5 minutes at room temperature, making a total of 3000 cycles) places heavy demands on the elasticity and adhesive capacity of the oxide. The test results in Fig. 4 show that the resistance of Alleima 253 MA in such difficult conditions is superior to that of both ASTM TP310 and EN 1.4828 (ASTM TP309). The very good properties of this grade in cyclic conditions have been achieved by adding rare earth metals and silicon.

Figure 3. Oxidation in air during cyclic testing 5x24 h with cooling to room temperature every 24 h. Comparison of Alleima 253 MA with four other high temperature materials.
1 = EN 1.4828 (ASTM TP309)
2 = ASTM TP446
3 = ASTM TP310
4 = Sandvik 253 MA
5 = Alloy 800 H

Figure 4. Oxidation in air during 1000 h cyclic exposure. The cycles comprise 15 min. at the testing temperature and 5 min at room temperature. The curves represent averages.

Figure 4. Oxidation in air during 1000 h cyclic exposure. The cycles comprise 15 min. at the testing temperature and 5 min at room temperature. The curves represent averages.


Carburizing atmosphere

Carburization can occur when a material comes into contact with hot gases with high carbon activity, e.g. hydrocarbons. The degree of carburization depends on the composition of the material and on the carbon and oxygen contents of the gas.

Thanks to the relatively high chromium content and the addition of silicon and rare earth metals, a protective oxide is easily formed on the surface of Alleima 253 MA material. Carburization resistance is, therefore, good. Fig. 5 shows carburization after 500 h at different temperatures, in a mixture of about 10% methane and about 90% argon containing 0.5% oxygen. As can be seen, Alleima 253 MA is less prone to carburization at high temperatures in these conditions than ASTM TP310 and Alloy 800H.

In alternately oxidizing and carburizing atmospheres and carburizing slags, Alleima 253 MA is slightly more prone to carburization than steels of higher chromium and/or nickel content.

Figure 5. Carburization of a cylindrical test piece at 0.5 mm (0.02 in.) distance from the surface after testing for 500 h at different temperatures in about 10% CH4 + about 90% Ar + 0.5% O2 .

Other gaseous atmospheres

In addition to its very good oxidation resistance in air, Alleima 253 MA is also highly resistant to other atmospheres. The highly protective oxide layer makes it possible to use this steel at high temperatures in atmospheres containing sulphur and other aggressive compounds.

Alleima 253 MA is more resistant than the higher alloyed 25Cr/20Ni steels to combustion gas attacks in cyclic conditions. It has an equivalent resistance, compared to the same grades, in conditions which are virtually isothermal. Alleima 253 MA can also be used in nitrogen-containing atmospheres provided that the gas contains enough oxygen to form a protective oxide layer. In gas shields containing little or no oxygen the resistance of Alleima 253 MA is inferior to that of Alloy 800H and 25Cr/20Ni steels as illustrated in Fig. 6. Thus, the grade is not recommended for use in muffle tubes using cracked ammonia gas.


Figure 6. Testing for 400 h at 825°C (1515°F) in nitrogen containing 43 and 205 ppm O2 , respectively.

Salt and metal melts

Compared with conventional austenitic stainless steels, Alleima 253 MA has good resistance to cyanide melts and neutral salt melts and also to metal melts, e.g. lead, at high temperatures. Its resistance to metal melts is to a great extent determined by the oxygen content of the melt. As with other alloyed steels, corrosion is greatest at the surface of the metal bath.

Wet corrosion

Alleima 253 MA is not generally used in conditions requiring great resistance to wet corrosion. The steel is, however, slightly more resistant than ASTM TP304 to stress corrosion cracking in chloride bearing aqueous solutions. Its resistance is more or less the same as that of ASTM TP316.

Bending

Annealing after cold bending is not normally necessary, but this should be reviewed depending on the degree of bending and the operating conditions.

If cold bending has exceeded 10–20%, we recommend solution annealing for tubes that are to be used at temperatures above about 800°C (1450°F), and when the highest possible creep strength is required in the bent tube.

Hot bending should be carried out at 1100–850°C (2050–1560°F) and should be followed by solution annealing.

Forms of supply

Seamless tube and pipe in Alleima 253 MA is supplied in dimensions up to 260 mm (10.2 in.) outside diameter in the solution-annealed and white-pickled condition or solution annealed by a bright-annealing process.

Other forms of supply

  • Fittings
  • Welded tube and pipe
  • Strip
  • Wire, drawn or ground
  • Bar steel
  • Plate, sheet and wide strip

Heat treatment

Tubes are delivered in the heat treated condition. If another heat treatment is needed after further processing, the following is recommended:

Stress relieving

850-950°C (1560-1740°F), 10-15 minutes, cooling in air.

Solution annealing

1050-1150°C (1920-2100°F), 5-20 minutes, rapid cooling in air or water.

Mechanical properties

Metric units, at 20°C
Proof strength Tensile strength Elong. Elong. Hardness
Rp0.2a) Rp1.0a) Rm Ab) A2" Vickers
MPa MPa MPa % %
≥310 ≥350 650-850 ≥40 ≥40 ≈190

1 MPa = 1 N/mm2

Imperial units, at 68°F
Proof strength Tensile strength Elong. Elong. Hardness
Rp0.2a) Rp1.0a) Rm Ab) A2" Vickers
ksi ksi ksi % %
≥45 ≥51 94-123 ≥40 ≥40 ≈190

a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength, respectively.
b) Based on L0 = 5.65 √S0 where L0 is the original gauge length and S0 the original cross-section area

At high temperatures

Metric units
Temperature Proof strength Tensile strength
°C Rp.02 Rp1.0 Rm
MPa MPa MPa
100 ≥225 ≥265 ≥550
200 ≥189 ≥215 ≥475
300 ≥170 ≥200 ≥440
400 ≥160 ≥190 ≥425
500 ≥150 ≥180 ≥400
600 ≥140 ≥165 ≥340
Imperial units
Temperature Proof strength Tensile strength
°F Rp.02 Rp1.0 Rm
ksi ksi ksi
200 ≥33.5 ≥39.0 ≥80.5
400 ≥26.0 ≥31.0 ≥68.5
600 ≥24.5 ≥28.5 ≥63.6
800 ≥23.0 ≥27.5 ≥61.0
1000 ≥21.0 ≥25.5 ≥55.0
1200 ≥19.5 ≥23.0 ≥46.5

Creep strength

The creep and creep rupture strength values correspond to values evaluated by the Swedish Institute for Metals Research for inclusion in the Swedish Standard. The evaluation is based on data submitted by AB Sandvik Materials Technology and Outokumpu Stainless and tests made by the Swedish Institute for Metals Research. The values apply to tube, pipe, sheet, plate and bar steel.

The higher values given in parentheses apply to Alleima seamless tube and pipe only. The basic values have been determined by testing at intervals of 100°C and at 750°C (1380°F), under uniaxial stress and with a constant load. The mean values in the tables below have been evaluated from the test results with the aid of linear regression of the logarithmic relationship between stress and time. This evaluation has also provided the basis of interpolation and extrapolation of temperatures and times.

The temperature above which design calculations are based on creep rupture strength instead of Rp0.2 proof strength, can be read off from Fig. 1. For Alleima 253 MA this temperature is about 550°C (1020°F). Fig. 2 shows the relationship between nominal stress and minimum creep rate, measured during testing under constant load.

Metric units
Temperature Creep strength 1% Creep rupture strength
°C 10 000 h 100 000 h 10 000 h 100 000 h
MPa MPa MPa MPa
525 - - - 162
550 - - - 128
575 - - 167 102
600 117 70 138 82
625 93 55 112 64
650 75 42 94 52
675 59 32 76 43
700 46 25 62 33
725 37 20 50 27
750 31 16 41 22
775 25 13 33 18
800 20 11 27 (28) 15 (16)
825 17 9.4 22 (23) 12 (14)
850 14 8.0 18 (20) 10 (12)
875 12 6.7 15 (17) 8.8 (10)
900 10 5.7 13 (14) 7.5 (8.4)
925 8.5 4.8 11 (12) 6.6 (7.2)
950 7.3 4.0 9.6 (10.5) 5.7 (6.3)
975 6.3 3.5 8.2 (9.0) 5.0 (5.8)
1000 5.4 3.0 7.0 (7.8) 4.3 (4.9)
1025 - - 6.2 (6.6) 3.8
1050 - - 5.5 (5.7) 3.3
1075 - - 4.9 3.0
1100 - - 4.3 2.6
Imperial units
Temperature Creep strength 1% Creep rupture strength
°F 10 000 h 100 000 h 10 000 h 100 000 h
ksi ksi ksi ksi
1000 - - - 20.9
1050 - - - 16.1
1100 - - 21.2 12.6
1150 13.9 8.3 17.1 9.7
1200 10.9 6.1 13.8 7.5
1250 8.4 4.5 10.7 5.9
1300 6.5 3.5 8.6 4.6
1350 5.1 2.8 6.8 3.8
1400 4.1 2.2 5.5 2.9
1450 3.2 1.7 4.3 (4.4) 2.5
1500 3.6 1.42 3.4 (3.6) 1.9 (2.1)
1550 2.2 1.19 2.7 (3.0) 1.5 (1.8)
1600 1.7 0.99 2.2 (2.5) 1.25 (1.5)
1650 1.45 0.81 1.9 (2.0) 1.07 (1.26)
1700 1.23 0.68 1.6 (1.7) 0.93 (1.04)
1750 1.04 0.58 1.33 (1.46) 0.80 (0.88)
1800 0.87 0.49 1.13 (1.03) 0.70 (0.75)
1850 - - 0.96 (1.03) 0.59 (0.68)
1900 - - 0.84 (0.88) 0.51
1950 - - 0.75 (0.77) 0.45
2000 - - 0.67 0.39

Fig. 1. Proof strength Rp0.2 and creep rupture strength at 10 000 and 100 000 h.

Fig. 2 Relationship between nominal stress and minimum creep rate at 600 –1100°C (1110–2010°F).

Physical properties

Density: 7.8 g/cm3, 0.28 lb/in3

Relative magnetic permeability

1.003 (typical value)

Thermal conductivity
Temperature, °CW/m °CTemperature, °FBtu/ft h °F
20 13 68 7.5
100 14 200 8.5
200 16 400 9.5
300 18 600 10.5
400 20 800 11.5
500 21 1000 12.5
600 23 1200 13.5
700 24 1400 14.5
800 25 1600 15
900 26 1800 16
1000 28 2000 17
1100 29 - -
Specific heat capacity
Temperature, °CJ/kg °CTemperature, °FBtu/ft h °F
20 490 68 0.12
100 515 200 0.12
200 540 400 0.13
300 565 600 0.14
400 580 800 0.14
500 600 1000 0.15
600 615 1200 0.15
700 630 1400 0.15
800 645 1600 0.16
900 655 1800 0.16
1000 665 2000 0.16
1100 680 - -
Thermal expansion1)
Temperature, °CPer °CTemperature, °FPer °F
30-100 16.5 86-200 9.5
30-200 17 86-400 9.5
30-300 17 86-600 9.5
30-400 17.5 86-800 10
30-500 18 86-1000 10
30-600 18 86-1200 10
30-700 18.5 86-1400 10.5
30-800 19 86-1600 10.5
30-900 19 86-1800 11
30-1000 19.5 - -

1) mean values in temperature ranges (x10-6)

Resistivity
Temperature, °CµΩmTemperature, °FµΩin.
20 0.84 68 33.2
100 0.91 200 35.4
200 0.97 400 38.1
300 1.02 600 40.3
400 1.07 800 42.3
500 1.11 1000 44.1
600 1.15 1200 45.7
700 1.18 1400 47.1
800 1.21 1600 48.2
900 1.23 1800 49.2
1000 1.26 2000 50.5
1100 1.29 - -
Modulus of elasticity1)
Temperature, °CMPaTemperature, °Fksi
20 200 68 28.5
200 185 400 27.0
400 170 800 24.0
600 155 1200 21.5
800 135 1400 20.0
1000 120 1800 17.5

1) (x103)

Structural stability

Because Sandvik 253 MA contains less chromium, and because of the addition of nitrogen the grade is less prone to sigma phase embrittlement than 25Cr/20Ni steels. See Fig. 7.

Figure 7. Time-Temperature- Transformation (TTT) diagram showing 1% sigma phase formation curves. The figures at the measuring points refer to sigma phase percentages by volume.

Welding

The weldability of Alleima 253MA is good. Suitable methods of fusion welding are manual metal-arc welding (MMA/SMAW) and gas-shielded arc welding, with the TIG/GTAW method as first choice.

In common with all austenitic stainless steels, Alleima 253MA has low thermal conductivity and high thermal expansion. Welding plans should therefore be carefully selected in advance, so that distortions of the welded joint are minimized. If residual stresses are a concern, solution annealing can be performed after welding.

For Alleima 253MA, heat-input of <1.5 kJ/mm and interpass temperature of <150°C (300°F) are recommended.

Recommended filler metals

TIG/GTAW or MIG/GMAW welding

EN ISO 14343-A G 21 10 N / W.no (EN no.) 1.4829

MMA/SMAW welding

EN ISO 3581-A E Z 23 10 N R 12

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.