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Related Specifications
- EN 1.4439
Properties
Chemical Composition
S31703 Sheet and Plate
ASTM A240
| Chemical Element | % Present |
|---|---|
Carbon (C) | 0.00 - 0.03 |
Chromium (Cr) | 18.00 - 20.00 |
Nickel (Ni) | 11.00 - 15.00 |
Manganese (Mn) | 0.00 - 2.00 |
Phosphorous (P) | 0.00 - 0.04 |
Sulphur (S) | 0.00 - 0.03 |
Silicon (Si) | 0.00 - 0.75 |
Molybdenum (Mo) | 3.00 - 4.00 |
Nitrogen (N) | 0.00 - 0.10 |
Iron (Fe) | Balance |
Mechanical Properties
Sheet and Plate
ASTM A240
| Mechanical Property | Value |
|---|---|
Proof Stress | 205 Min MPa |
Tensile Strength | 515 Min MPa |
Elongation A50 mm | 40 Min % |
Applications
- Air Pollution control
- Chemical and petrochemical processing
- Explosives
- Food and beverage processing
- Petroleum refining
- Power generation-condensers
- Pulp and paper
Characteristics
- Excellent corrosion resistance in a wide range of chemicals
- Good formability
- Good weldability
Additional Information
Corrosion Resistance
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.
Welding
317L can be readily welded by a full range of conventional welding methods such as: Shielded metal arc welding (SMAW) Gas tungsten arc welding, TIG (GTAW) Gas metal arc welding, MIG (GMAW) Flux-cored arc welding (FCAW) Plasma arc welding (PAW) Submerged arc welding (SAW) Subsequent passes may cause precipitates of secondary phases in the weld metal. For this reason a low heat input and a maximum interpass temperature of 100ºC should be used.
Machinability
Machining stainless steel grade 317L requires low speeds and constant feeds to reduce its tendency to work harden. This steel is tougher than grade 304 stainless steel with a long stringy chip; however, using chip breakers is recommended. Welding can be performed using most of the conventional fusion and resistance methods. Oxyacetylene welding should be avoided. AWS E/ER 317L filler metal is recommended.
Conventional hot working processes can be performed. The material should be heated to 1149-1260°C (2100-2300°F); however, it should not be heated below 927°C (1700°F). To optimize corrosion resistance, a post-work annealing is recommended.
Shearing, stamping, heading and drawing are possible with grade 317L stainless steel, and post-work annealing is recommended to eliminate internal stresses. Annealing is performed at 1010-1121°C (1850-2050°F), which should be followed by rapid cooling.
Grade 317L stainless steel does not respond to heat treatment.
