General
Mechanical
Property | Temperature | Value | Comment |
---|---|---|---|
Charpy impact energy | -196.0 °C | 60 J Show Supplier Material materials with Charpy impact energy of 60 J | EN 13445-2 (UFPV-2) and EN 10216-5 |
Elastic modulus | 20.0 °C | 195 GPa Show Supplier Material materials with Elastic modulus of 195 GPa | |
100.0 °C | 190 GPa Show Supplier Material materials with Elastic modulus of 190 GPa | ||
200.0 °C | 182 GPa Show Supplier Material materials with Elastic modulus of 182 GPa | ||
300.0 °C | 174 GPa Show Supplier Material materials with Elastic modulus of 174 GPa | ||
400.0 °C | 166 GPa Show Supplier Material materials with Elastic modulus of 166 GPa | ||
500.0 °C | 158 GPa Show Supplier Material materials with Elastic modulus of 158 GPa | ||
Elongation | 23.0 °C | 35 % Show Supplier Material materials with Elongation of 35 % | min. |
Elongation A2 | 23.0 °C | 35 % Show Supplier Material materials with Elongation A2 of 35 % | min. |
Hardness, Rockwell B | 23.0 °C | 96 [-] Show Supplier Material materials with Hardness, Rockwell B of 96 [-] | max. |
Tensile strength | 23.0 °C | 675 - 850 MPa Show Supplier Material materials with Tensile strength of 675 - 850 MPa | |
Yield strength Rp0.1 | 20.0 °C | 340 MPa Show Supplier Material materials with Yield strength Rp0.1 of 340 MPa | min. |
100.0 °C | 270 MPa Show Supplier Material materials with Yield strength Rp0.1 of 270 MPa | min. | |
200.0 °C | 225 MPa Show Supplier Material materials with Yield strength Rp0.1 of 225 MPa | min. | |
300.0 °C | 200 - 205 MPa Show Supplier Material materials with Yield strength Rp0.1 of 200 - 205 MPa | min. | |
350.0 °C | 195 MPa Show Supplier Material materials with Yield strength Rp0.1 of 195 MPa | min. | |
400.0 °C | 185 - 190 MPa Show Supplier Material materials with Yield strength Rp0.1 of 185 - 190 MPa | min. | |
450.0 °C | 175 MPa Show Supplier Material materials with Yield strength Rp0.1 of 175 MPa | min. | |
500.0 °C | 170 - 180 MPa Show Supplier Material materials with Yield strength Rp0.1 of 170 - 180 MPa | min. | |
Yield strength Rp0.2 | 20.0 °C | 310 MPa Show Supplier Material materials with Yield strength Rp0.2 of 310 MPa | min. |
100.0 °C | 230 MPa Show Supplier Material materials with Yield strength Rp0.2 of 230 MPa | min. | |
200.0 °C | 190 MPa Show Supplier Material materials with Yield strength Rp0.2 of 190 MPa | min. | |
300.0 °C | 170 - 175 MPa Show Supplier Material materials with Yield strength Rp0.2 of 170 - 175 MPa | min. | |
350.0 °C | 165 MPa Show Supplier Material materials with Yield strength Rp0.2 of 165 MPa | min. | |
400.0 °C | 155 - 160 MPa Show Supplier Material materials with Yield strength Rp0.2 of 155 - 160 MPa | min. | |
450.0 °C | 145 MPa Show Supplier Material materials with Yield strength Rp0.2 of 145 MPa | min. | |
500.0 °C | 140 - 148 MPa Show Supplier Material materials with Yield strength Rp0.2 of 140 - 148 MPa | min. | |
Thermal
Property | Temperature | Value | Comment |
---|---|---|---|
Coefficient of thermal expansion | 100.0 °C | 1.6E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.6E-5 1/K | for 30°C to the mentioned temperature |
200.0 °C | 1.6E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.6E-5 1/K | for 30°C to the mentioned temperature | |
300.0 °C | 1.65E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.65E-5 1/K | for 30°C to the mentioned temperature | |
400.0 °C | 1.65E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.65E-5 1/K | for 30°C to the mentioned temperature | |
500.0 °C | 1.7E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.7E-5 1/K | for 30°C to the mentioned temperature | |
600.0 °C | 1.7E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.7E-5 1/K | for 30°C to the mentioned temperature | |
700.0 °C | 1.75E-5 1/K Show Supplier Material materials with Coefficient of thermal expansion of 1.75E-5 1/K | for 30°C to the mentioned temperature | |
Specific heat capacity | 20.0 °C | 485 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 485 J/(kg·K) | |
100.0 °C | 510 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 510 J/(kg·K) | ||
200.0 °C | 535 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 535 J/(kg·K) | ||
300.0 °C | 565 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 565 J/(kg·K) | ||
400.0 °C | 585 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 585 J/(kg·K) | ||
500.0 °C | 600 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 600 J/(kg·K) | ||
600.0 °C | 615 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 615 J/(kg·K) | ||
700.0 °C | 625 J/(kg·K) Show Supplier Material materials with Specific heat capacity of 625 J/(kg·K) | ||
Thermal conductivity | 20.0 °C | 10 W/(m·K) Show Supplier Material materials with Thermal conductivity of 10 W/(m·K) | |
100.0 °C | 12 W/(m·K) Show Supplier Material materials with Thermal conductivity of 12 W/(m·K) | ||
200.0 °C | 14 W/(m·K) Show Supplier Material materials with Thermal conductivity of 14 W/(m·K) | ||
300.0 °C | 16 W/(m·K) Show Supplier Material materials with Thermal conductivity of 16 W/(m·K) | ||
400.0 °C | 18 W/(m·K) Show Supplier Material materials with Thermal conductivity of 18 W/(m·K) | ||
500.0 °C | 20 W/(m·K) Show Supplier Material materials with Thermal conductivity of 20 W/(m·K) | ||
600.0 °C | 21 W/(m·K) Show Supplier Material materials with Thermal conductivity of 21 W/(m·K) | ||
700.0 °C | 23 W/(m·K) Show Supplier Material materials with Thermal conductivity of 23 W/(m·K) | ||
Chemical properties
Property | Value | Comment | |
---|---|---|---|
Carbon | 0.02 % Show Supplier Material materials with Carbon of 0.02 % | max. | |
Chromium | 20 % Show Supplier Material materials with Chromium of 20 % | ||
Copper | 0.7 % Show Supplier Material materials with Copper of 0.7 % | ||
Iron | Balance | ||
Manganese | 1 % Show Supplier Material materials with Manganese of 1 % | max. | |
Molybdenum | 6.1 % Show Supplier Material materials with Molybdenum of 6.1 % | ||
Nickel | 18 % Show Supplier Material materials with Nickel of 18 % | ||
Nitrogen | 0.2 % Show Supplier Material materials with Nitrogen of 0.2 % | ||
Phosphorus | 0.03 % Show Supplier Material materials with Phosphorus of 0.03 % | max. | |
Silicon | 0.8 % Show Supplier Material materials with Silicon of 0.8 % | max. | |
Sulfur | 0.01 % Show Supplier Material materials with Sulfur of 0.01 % | max. |
Technological properties
Property | ||
---|---|---|
Application areas | Sandvik 254 SMO is used in the following applications: Trademark information: 254 SMO is a trademark owned by Outokumpu OY. | |
Certifications | Approvals: At high temperatures: Intermetallic phases are precipitated within the temperature range of 600–1000°C (1110–1830°F). Therefore, the steel should not be exposed to these temperatures for prolonged periods. | |
Cold Forming | The excellent formability of Sandvik 254 SMO permits cold bending to very tight bending radii. Annealing is not normally necessary after cold bending. | |
Corrosion properties | In solutions containing halides such as chloride and bromide ions, conventional stainless steels can be readily attacked by local corrosion in the form of pitting corrosion, crevice corrosion or stress corrosion cracking (SCC). In acid environments, the presence of halides also accelerates general corrosion. General corrosion: In pure sulphuric acid, Sandvik 254 SMO is much more resistant than ASTM TP316, and in naturally aerated sulphuric acid containing chloride ions Sandvik 254 SMO exhibits higher resistance than '904L', see Figure 2. Intergranular corrosion: Sandvik 254 SMO has a very low carbon content. This means that there is very little risk of carbide precipitation during heating, for example when welding. The steel passes the Strauss test (ASTM A262, practice E) even after sensitizing for one hour at 600–1000°C (1110–1830°F). However, due to the high alloying content of the steel, inter-metallic phases can precipitate at the grain boundaries in the temperature range 600–1000°C (1110–1830°F). These precipitations do not involve any risk of intergranular corrosion in the environments in which the steel is intended to be used. Thus, welding can be carried out without any risk of intergranular corrosion. Pitting and crevice corrosion: The pitting and crevice corrosion resistance of stainless steel is primarily determined by the content of chromium, molybdenum and nitrogen. Manufacture and fabrication, e.g. welding, are also of vital importance for the actual performance in service. A parameter for comparing the resistance to pitting in chloride environments is the PRE number (Pitting Resistance Equivalent). The PRE is defined as, in weight-%, PRE = %Cr + 3.3 x %Mo + 16 x %N. PRE-value for Sandvik 254 SMO = ≥42,5. The results of laboratory determination of the critical pitting temperature (CPT) in 3 % NaCl are shown in Figure 3, where it can be seen that Sandvik 254 SMO possesses very good resistance in water containing chlorides. Sandvik 254 SMO is, therefore, a suitable material for use in seawater. Stress corrosion cracking (SCC): Ordinary austenitic steels of the ASTM TP304 and TP316 type are prone to stress corrosion cracking (SCC) in chloride-containing solutions at temperatures exceeding about 60°C (140°F). For the austenitic steels, resistance to SCC increases with higher nickel and molybdenum contents. The tables below show the results of two accelerated tests, clearly demonstrating that Sandvik 254 SMO has a very good resistance to SCC. Stress corrosion cracking tests in boiling 25% NaCl solution, pH=1.5. U-bend specimens. Stress corrosion cracking tests. Drop evaporation method* Stress: 0.9xRp0.2 Crevice corrosion: The weak point of conventional stainless steels is their limited resistance to crevice corrosion. In seawater, for example, there is a considerably greater risk of crevice corrosion under gaskets, deposits or fouling. Tests in natural seawater at 60°C (140°F) have shown that Sandvik 254 SMO can be exposed for prolonged periods without suffering crevice corrosion. Figure 4 shows the results of accelerated crevice corrosion tests. | |
Heat Treatment | The tubes are delivered in heat treated condition. If additional heat treatment is needed due to further processing the following is recommended. Solution annealing: 1150–1200°C (2100–2190°F), quenching in water. Thin-walled tubes min. 1130°C (2060°F), quenching in air/water. | |
Machining | Sandvik 254 SMO is a high alloyed austenitic stainless steel and thus tougher inserts in metal cutting are needed than is the case for lower alloyed austenitic grades. When machining Sandvik 254 SMO considerably lower cutting speeds are recommended compared to the grades Sanmac 304/304L and Sanmac 316/316L, which have improved machinability. Avoid abrasion against copper/copper alloys or other similar metals which, if present in metallic form, can cause cracks during subsequent welding, hot processing or heat treatment. | |
Other | Forms of supply: Seamless tube and pipe are supplied in dimensions up to 230 mm (9.06 in.) outside diameter. The delivery condition is either solution annealed and white pickled, or solution annealed in a bright annealing process. Other forms of supply: | |
Welding | The weldability of Sandvik 254 SMO 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 fully austenitic stainless steels, Sandvik 254 SMO 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 Sandvik 254 SMO, heat-input of <1.5 kJ/mm and interpass temperature of <100°C (210°F) are recommended. A string bead welding technique should be used. Nickel alloys with high molybdenum and chromium must be used as filler metals to have good corrosion resistance in the as-welded condition. Recommended filler metals:
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