Sandvik 5R75 is an austenitic, titanium-stabilized stainless chromium–nickel–molybdenum steel.
EN Number: 1.4571
EN Name: X6CrNiMoTi17-12-2
DIN: X 6 CrNiMoTi 17 12 2
Seamless tube and pipe:
- ASTM A312
- EN 10216-5
- DIN 17456, 17458
- SS 14 23 50
- NFA 49-117
- ASTM A213, A269 and A312
Chemical composition (nominal)
Sandvik 5R75 is used for a variety of industrial applications. Typical examples are heat exchangers, condensers, pipelines, cooling and heating coils in the chemical, petrochemical and pulp and paper industries.
Sandvik 5R75 has good resistance to
- Organic acids at high concentrations and temperatures
- Inorganic acids, e.g. phosphoric and sulfuric acids, at moderate concentrations and temperatures. The steels can also be used in sulfuric acid of concentrations above 90% at low temperature.
- Salt solutions, e.g. sulfates, sulfides and sulfites
- Caustic environments
Sandvik 5R75 has better resistance to intergranular corrosion than unstabilized steels. The addition of titanium prevents precipitation of chromium carbides in the grain boundaries after prolonged heating in the temperature range 450- 850°C (840-1560°F).
Pitting and crevice corrosion
Resistance to these types of corrosion improves with increasing molybdenum content and Sandvik 5R75 with about 2.1% Mo has substantially higher resistance than steels of type AISI 304/304L.
Stress corrosion cracking
Austenitic stainless steels are susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F), if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. Such service conditions should therefore be avoided. Conditions when plants are shut down must also be considered as the condensates which are then formed can develop a chloride content that leads to both stress corrosion cracking and pitting.
In applications demanding high resistance to stress corrosion cracking, austenitic- ferritic steels, e.g. Sandvik SAF 2304 or SAF 2205, are recommended. See data sheets S-1871-ENG and S-1874-ENG.
Sandvik 5R75 can be used in
- Air up to 850°C (1560°F)
- Steam up to 750°C (1380°F)
Creep behavior should also be taken into account when using the steel in the creep range. In flue gases containing sulfur, the corrosion resistance is reduced. In such environments these steels can be used at temperatures up to 600-750°C (1110-1380°F) depending on service conditions. Factors to consider are whether the atmosphere is oxidizing or reducing, i.e. the oxygen content, and whether impurities such as sodium and vanadium are present.
Annealing after cold bending is not normally necessary, but this point must be decided with regard to the degree of bending and the operating conditions. Heat treatment, if any, should take the form of stress-relieving or solution-annealing, see under "Heat treatment".
Hot bending is carried out at 1100-850°C (2010-1560°F) and should be followed by solution-annealing.
Forms of supply
Seamless tube and pipe
Tube and pipe are normally delivered in the solution-annealed and white-pickled condition. Smaller sizes may be bright-annealed. The size range can be seen from the principal size range can be seen from Fig. 1.
Hollow bar is supplied solution-annealed and white-pickled.
The tubes are normally delivered in heat treated condition. If additional heat treatment is needed after further processing the following is recommended.
850-950°C (1560-1740°F), 10-15 minutes, cooling in air.
1000-1100°C (1830-2010°F), 5-20 minutes, rapid cooling in air or water.
At 20°C (68°F)
|Proof strength||Tensile strength||Elong||Hardness|
|Rp0.2a) c)||Rp1.0a) c)||Rmc)||Ab)||Vickers|
1 MPa = 1 N/mm2
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.
c) For hot finished tube and pipe with wall thickness greater than 10 mm (0.4 in.) the minimum values for proof strength may fall short of the stated values by 20 MPa (2.9 ksi) and the range for the tensile strength is 490-690 MPa.
d) NFA 49-117 with min 45% can be fulfilled.
Due to its austenitic microstructure, Sandvik 5R75 has very good impact strength both at room temperature and at cryogenic temperatures.
Tests have demonstrated that the steel fulfils the requirements (60 J (44 ft-lb) at -196 oC (-320 oF)) according to the European standards EN 13445-2 (UFPV-2) and EN 10216-5.
At high temperatures
d) For hot finished tube and pipe with wall thicknesses greater than 10 mm (0.4 in.) the proof strength values may be slightly lower but still fulfill the requirements according to DIN 17458 and SS 14 23 50.
Density: 8.0 g/cm3, 0.29 lb/in3
|Temperature, °C||W/m °C||Temperature, °F||Btu/ft h °F|
|Temperature, °C||J/kg °C||Temperature, °F||Btu/lb °F|
|Temperature, °C||Per °C||Temperature, °F||Per °F|
1) Mean values in temperature ranges (x10-6)
|Temperature, °C||MPa||Temperature, °F||ksi|
The weldability of Sandvik 5R75 is good. Welding must be carried out without preheating and subsequent heat treatment is normally not required. 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.
For Sandvik 5R75, 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
ISO 14343 S 19 12 3 Nb / AWS A5.9 ER318 (e.g. Exaton 19.12.3.Nb )
ISO 3581 E 19 12 3 Nb R / AWS A5.4 E318-17
Sandvik 5R75 has good machining properties. Detailed recommendations for the choice of tools and cutting data are provided in brochures S-0291-ENG and S-1492-ENG.