General Characteristics
347/4550 is a niobium stabilized alternative 321/4541 with improved intergranular corrosion resistance and good mechanical properties at high temperatures. 347/4550 is particularly useful in applications with intermittent heating in the range 400–900 °C/750–1650 °F. 347/4550 is an austenitic stainless steel that belongs to the standard CrNi stainless steels. 347/4550 can be welded in all dimensions without becoming susceptible to intergranular corrosion.
The austenitic CrNi standard grades are the most widely used group of stainless steels. Their well-balanced material properties make them suitable for the fabrication of many products.
Typical Applications
High temperature gaskets
Rocket engine parts
Expansion joints
Aircraft collector rings
Exhaust manifolds
Chemical production equipment
Flanges and valves
Product forms, available sizes and finishes
Flat
Product type | Finishes | Thickness | Width |
Black hot band | 1U | 2,70-10,00 | 1000-1550 |
Cold rolled coil | 2B, 2BB, 2C, 2D, 2E, 2G, 2H, 2J, 2R | 0,05-4,00 | 3-1600 |
Cold rolled sheet | 2B, 2BB, 2D, 2E, 2G, 2H, 2J, 2R | 0,25-4,00 | 350-1250 |
Hot rolled coil, pickled | 1C, 1D, 1G, 1U | 2,00-10,00 | 50-1550 |
Precision strip | 2H, 2R | 0,05-1,50 | 3-649 |
Quarto plate | 1D | 5,00-130,00 | 400-3200 |
Long
| Product type | Thickness | Width | |
Cast billet | 127,00-180,00 | 127-180 | |
Cold drawn bar hex | 8,00-25,40 | 8-25 | |
Cold drawn bar round | 6,00-25,40 | 6-25 | |
Cold drawn bar square | 8,00-22,00 | 8-22 | |
Forged billet round | 200,00-230,00 | 200-230 | |
Forged billet square | 200,00-230,00 | 200-230 | |
Hot rolled / Black bar round | 75,00-230,00 | 75-230 | |
Peeled / turned bar round | 70,00-170,00 | 70-170 | |
Rolled billet round | 90,00-200,00 | 90-200 | |
Rolled billet square | 75,00-200,00 | 75-200 | |
Wire rod (Rod coil) hex | 9,00-27,00 | 9-27 | |
Wire rod (Rod coil) round | 5,00-27,00 | 5-27 | |
Wire rod (Rod coil) square | 9,00-24,00 | 9-24 |
Chemical Composition
The chemical composition may vary slightly between different product standards. The required standard will be fully met as specified on the order.
The typical chemical composition for this grade is given in the table below, together with composition limits given for the product according to different standards. The required standard will be fully met as specified on the order.
The chemical composition is given as % by mass.
| C | Mn | Cr | Ni | Mo | |
| Typical | 0.05 | 17.5 | 9.5 | ||
ASME II A SA-240 | ≤0.08 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | |
ASME II A SA-240 | 0.04-0.10 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | |
ASTM A240 | ≤0.08 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | |
ASTM A240 | 0.04-0.10 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | |
EN 10028-7 | ≤0.08 | ≤2.00 | 17.00-19.00 | 9.00-12.00 | |
EN 10088-2 | ≤0.08 | ≤2.0 | 17.0-19.0 | 9.0-12.0 | |
EN 10088-3 | ≤0.08 | ≤2.0 | 17.0-19.0 | 9.0-12.0 | |
IS 6911 | ≤0.08 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | ≤0.70 |
IS 6911 | 0.04-0.10 | ≤2.00 | 17.0-19.0 | 9.0-13.0 | ≤0.70 |
Mechanical Properties
| Standard | Rp0.2 | Rp1.0 | Rm | Elongation | Rockwell | HB |
MPa | MPa | MPa | % | |||
Product type: Cold rolled coil and sheet | ||||||
Typical (thickness 1 mm) | 275 | 300 | 620 | 82 | ||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
Product type: Hot rolled coil and sheet | ||||||
Typical (thickness 4 mm) | 320 | 365 | 640 | 53 | ||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 201 | |||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
Product type: Hot rolled quarto plate | ||||||
Typical (thickness 15 mm) | 260 | 290 | 595 | 45 | ||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
ASME II A SA-240 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
ASTM A240 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
EN 10028-7 | ≥ 200 | ≥ 240 | 500-700 | ≥ 40 | ||
EN 10088-2 | ≥ 200 | ≥ 240 | 500-700 | ≥ 40 | ||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
IS 6911 | ≥ 205 | ≥ 515 | ≤ 92HRB | ≤ 201 | ||
Product type: Wire rod | ||||||
Typical | 250 | 280 | 580 | 45 | ||
Physical Properties (Data according to EN 10088)
| Density | Modulus of elasticity | Thermal exp. at 100 °C | Thermal conductivity | Thermal capacity | Electrical resistance | Magnetizable |
kg/dm3 | GPa | 10-6/°C | W/m°C | J/kg°C | µΩm | |
7,9 | 200 | 16,0 | 15 | 500 | 0,73 | No |
