Stainless Steel 317L Sheet/Plates
Great Steel & Metals offers superior quality stainless steel 317L sheet/plates which are molybdenum bearing austenitic stainless steel to all its customers. As compared to conventional stainless steels of chromium-nickel like alloy 304, alloy 317L offers increased resistance to the chemical attack. Also, as compared to the conventional stainless steels, higher creep, tensile and stress to rupture strength at elevated temperatures is offered by alloy 317L. During thermal processes and welding, alloy 317L provides resistance to sensitization.
Alloy 317L is corrosion resistant, low carbon austenitic chromium-nickel-molybdenum stainless steel. Superior resistance to general corrosion and chloride pitting is offered by alloy 317L on account of high levels of these elements as compared to the conventional 304/304Land 316/316L grades. In the strongly corrosive environments that contain chlorides, sulfurous media and other halides, the alloy provides improved resistance.
The alloy could be dual certified as Alloy 317 (UNS S 31700) with addition of nitrogen in it as a strengthening agent. In the annealed condition, alloy 317L is non magnetic.
- Air Pollution Control — flue gas desulfurization systems (FGD)
- Chemical and Petrochemical Processing
- Food and Beverage Processing
- Petroleum Refining
- Power Generation — condensers
- Pulp and Paper
The higher molybdenum content of Alloy 317L assures superior general and localized corrosion resistance in most media when compared with 304/304L and 316/316L stainless steels. Environments that don’t attack 304/304L stainless steel will normally not corrode 317L. One exception, however, are strongly oxidizing acids such as nitric acid. Alloys that contain molybdenum generally do not perform as well in these environments.
Alloy 317L has excellent corrosion resistance to a wide range of chemicals. It resists attack in sulfuric acid, acidic chlorine and phosphoric acid. It is used in handling hot organic and fatty acids often present in food and pharmaceutical processing applications.
The corrosion resistance of 317 and 317L should be the same in any given environment. The one exception is where the alloy will be exposed to temperatures in the chromium carbide precipitation range of 800 – 1500°F (427 – 816°C). Because of its low carbon content, 317L is the preferred material in this service to guard against intergranular corrosion.
In general, austenitic stainless steels are subject to chloride stress corrosion cracking in halide service. Although 317L is somewhat more resistant to stress corrosion cracking than 304/304L stainless steels, because of its higher molybdenum content, it is still susceptible.
The higher chromium, molybdenum and nitrogen content of 317L enhance its ability to resist pitting and crevice corrosion in the presence of chlorides and other halides. The Pitting Resistance Equivalent including Nitrogen number (PREN) is a relative measure of pitting resistance. The following chart offers a comparison Alloy 317L and other austenitic stainless steels.
1Pitting Resistance Equivelant, including Nitrogen, PREN = Cr + 3.3Mo + 16N
Weight % (all values are maximum unless a range is otherwise indicated)
0.12 BTU/lb-°F (32 – 212°F)
502 J/kg-°K (0 – 100°C)
Modulus of Elasticity
29.0 x 106 psi
Thermal Conductivity 212°F (100°C)
2540 – 2630°F
1390 – 1440°C
33.5 Microhm-in at 68°C
85.1 Microhm-cm at 20°C
Mean Coefficient of Thermal Expansion
Values at 68°F (20°C) (minimum values, unless specified)
Alloy 317L can be easily welded and processed by standard shop fabrication practices.
Working temperatures of 1652 – 2102°F (900 – 1150°C) are recommended for hot working processes. Do not work this alloy below 1742°F (950°C). If the final forming temperature falls below this threshold, a solution anneal of 1976 – 2156°F (1080 – 1180°C) is necessary. Rapid quenching is required.
The alloy is quite ductile and forms easily. The addition of molybdenum and nitrogen implies more powerful processing equipment may be necessary when compared with the standard 304/304L grades.
The cold work hardening rate of Alloy 317L makes it less machinable than 410 stainless steel. The table below provides relevant machining data.
Alloy 317L can be readily welded by most standard processes. A post weld heat treatment is not necessary.