Stainless Steel, Austenitic
317L Stainless Steel (S31703) Sheet & Plate
A lowcarbon, high molybdenum austenitic stainless steel with a higher nickel alloy content than 316L.
Alloy 317L (UNS S31703) is a low carbon corrosion resistant austenitic chromium-nickel-molybdenum stainless steel. The high levels of these elements assure the alloy has superior chloride pitting and general corrosion resistance to the conventional 304/304L and 316/316L grades. The alloy provides improved resistance relative to 316L in strongly corrosive environments containing sulfurous media, chlorides, and other halides.
It can be used in applications where it is not possible to anneal after welding and where maximum corrosion resistance is required. It provides good oxidation resistance in intermittent service to 1600 ° F and in continuous service to 1700 ° F.
This alloy combines excellent corrosion resistance with good mechanical properties, weldability, and formability, making it ideal for applications in chemical, petrochemical, and marine industries, as well as food processing and pharmaceutical equipment.
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Related Specifications
- 00Cr19Ni13Mo3
- 317L / UNS S31703
- SUS317L
- X2CrNiMo18-15-4 / 1.4438
- 317S12
- Z2CND18-15-04
- 03Х17Н14М3
- S31703
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 of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel with excellent corrosion resistance, particularly in aggressive chemical and chloride-containing environments. Its combination of durability, weldability, and resistance to chemical attack makes it suitable for a wide range of applications.
1. Chemical and Petrochemical Industry
Reactors, tanks, and vessels for corrosive chemicals
Heat exchangers and condensers
Piping systems handling acids and chlorides
Valves, fittings, and pumps in chemical processes
2. Marine and Seawater Applications
Components exposed to seawater or brackish water
Marine piping and structural equipment
Desalination plant components
3. Food and Pharmaceutical Industry
Processing equipment requiring corrosion resistance and hygiene
Storage tanks and piping for acidic or aggressive media
Heat exchangers, evaporators, and agitators
4. Industrial and Mechanical Applications
Fasteners, bolts, and screws in corrosive environments
Structural components in aggressive atmospheres
Components exposed to high humidity or saline conditions
Summary
317L stainless steel is widely used in chemical, marine, pharmaceutical, and industrial applications where superior corrosion resistance, especially to chlorides and oxidizing acids, is essential. Its low-carbon content ensures excellent weldability, making it ideal for fabricated components and complex assemblies.
Characteristics of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel designed for superior corrosion resistance and excellent performance in aggressive environments. It is widely used in industries requiring durability, chemical resistance, and good mechanical properties.
1. Superior Corrosion Resistance
High molybdenum content enhances resistance to pitting, crevice corrosion, and chemical attack, particularly in chloride or acidic environments.
Performs better than 316L in oxidizing and aggressive chemical media.
2. Austenitic Structure
Provides excellent ductility, toughness, and formability.
Maintains good mechanical properties at both high and low temperatures.
3. Low Carbon Content
Minimizes the risk of sensitization during welding.
Ensures resistance to intergranular corrosion even after heat exposure.
4. Weldability and Fabrication
Excellent weldability using standard methods such as TIG, MIG, and SMAW.
Can be easily formed into sheets, pipes, or complex components.
5. Mechanical Properties
Good tensile strength, yield strength, and elongation.
Maintains structural integrity under both static and dynamic loads.
Summary
317L stainless steel is characterized by high corrosion resistance, excellent weldability, good formability, and reliable mechanical properties. Its low carbon and high molybdenum content make it ideal for chemical, marine, pharmaceutical, and industrial applications, especially where resistance to chlorides and acids is critical.
Additional Information
Fabrication
Fabrication of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel with excellent corrosion resistance and good mechanical properties. It can be fabricated using standard industrial techniques including forming, welding, and machining.
1. Forming
Cold Working:
317L exhibits good ductility, making it suitable for bending, deep drawing, rolling, and stamping.
Work hardening occurs, so intermediate annealing may be required for extensive forming.
Hot Working:
Performed at elevated temperatures to reduce work hardening and improve ductility.
Typical hot working range: 1150–900°C (2100–1650°F).
2. Welding
Excellent weldability using TIG, MIG, SMAW, and FCAW methods.
Low carbon content minimizes sensitization and reduces risk of intergranular corrosion.
Filler metals such as ER317L or ER316L are commonly used to ensure corrosion resistance in welded joints.
3. Machining
Moderate machinability due to the austenitic structure.
Work hardens easily; sharp tools and rigid setups are recommended.
Carbide tools and proper cutting fluids improve tool life and surface finish.
4. Post-Fabrication Treatments
Annealing: Restores ductility and relieves stresses after heavy cold working.
Pickling and Passivation: Recommended to remove scale and restore optimal corrosion resistance after welding or hot forming.
5. Applications Related to Fabrication
Chemical and petrochemical processing equipment
Marine components and seawater piping
Food and pharmaceutical processing machinery
Heat exchangers, tanks, and vessels
Summary
317L stainless steel is highly fabricable, supporting cold and hot forming, welding, and machining. Its low carbon content ensures excellent weldability and corrosion resistance, making it ideal for chemical, marine, pharmaceutical, and industrial applications.
Weldability
Weldability of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel with excellent weldability, making it suitable for fabricating corrosion-resistant components in aggressive environments.
1. General Weldability
Can be welded using all standard fusion welding techniques:
TIG (GTAW)
MIG (GMAW)
SMAW (Shielded Metal Arc Welding)
FCAW (Flux-Cored Arc Welding)
Welds maintain good toughness, corrosion resistance, and mechanical strength.
2. Low Carbon Advantage
The low carbon content minimizes sensitization, preventing intergranular corrosion in welded zones.
Unlike higher carbon stainless steels, 317L does not require special post-weld heat treatment for corrosion resistance in most applications.
3. Filler Metal Recommendations
Suitable filler metals include:
ER317L (matching high-molybdenum, low-carbon composition)
ER316L (for less aggressive environments)
Filler selection ensures consistent corrosion resistance and mechanical properties in the weld.
4. Heat Input and Preparation
Moderate heat input is recommended to avoid excessive grain growth.
Clean joint surfaces free of oil, grease, or oxide scale ensure better weld quality.
Preheating is typically not required.
5. Post-Weld Considerations
Post-weld annealing is generally unnecessary unless the component is heavily stressed or exposed to very aggressive environments.
Pickling or passivation is recommended to restore the chromium oxide layer after welding.
6. Applications Related to Weldability
Chemical and petrochemical equipment
Marine piping and structural components
Food and pharmaceutical processing machinery
Heat exchangers, tanks, and vessels
Summary
317L stainless steel exhibits excellent weldability due to its low carbon content and austenitic structure. Proper filler selection and controlled welding techniques produce strong, corrosion-resistant joints, making 317L ideal for chemical, marine, pharmaceutical, and industrial applications.
Machinability
Machinability of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel. It offers moderate machinability, similar to other austenitic stainless steels, but certain characteristics require careful attention during machining.
1. Work Hardening
317L has a high tendency to work harden, especially during light cuts or repeated passes.
To reduce work hardening:
Use sharp, rigid tooling
Avoid shallow or interrupted cuts
Employ adequate lubrication and coolant
2. Tooling Recommendations
Carbide tools are preferred for efficient cutting and long tool life.
High-speed steel (HSS) tools can be used for lower-speed operations.
Rigid fixturing minimizes vibration and improves surface finish.
3. Cutting Conditions
Use moderate to low cutting speeds to avoid heat buildup.
Maintain adequate feed and depth of cut to reduce tool rubbing.
Continuous coolant flow improves tool life and chip evacuation.
4. Chip Formation
Produces long, ductile chips due to its austenitic structure.
Use chip breakers or controlled cutting techniques to manage chips effectively.
5. Surface Finish
Achievable with proper tooling and lubrication.
Avoid overheating, which can degrade the surface layer and reduce corrosion resistance.
6. Applications Related to Machining
Precision components in chemical and petrochemical equipment
Fittings, valves, and fasteners in aggressive environments
Piping, tanks, and industrial machinery requiring corrosion-resistant parts
Summary
317L stainless steel exhibits moderate machinability with a high work-hardening tendency. Proper tooling, cutting speeds, and coolant use are essential for effective machining. Its machinability combined with excellent corrosion resistance makes it suitable for chemical, marine, pharmaceutical, and industrial applications.
Corrosion Resistance
Corrosion Resistance of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel that provides excellent corrosion resistance in aggressive environments, particularly where chlorides or oxidizing acids are present. Its corrosion resistance is superior to that of 316L due to the higher molybdenum content.
1. General Corrosion Resistance
Resists oxidation and general atmospheric corrosion.
Performs well in moderate chemical environments, including mild acids and alkaline solutions.
Suitable for outdoor applications and industrial environments.
2. Pitting and Crevice Corrosion
High molybdenum content improves resistance to pitting and crevice corrosion.
Particularly effective in chloride-containing environments, such as seawater or brine solutions.
Outperforms 316L in marine and chemical processing applications.
3. Intergranular Corrosion Resistance
Low carbon content minimizes sensitization during welding.
Maintains resistance to intergranular corrosion (IGC) in welded components.
4. Resistance to Chemical Attack
Performs well in oxidizing acids such as nitric acid.
Provides moderate resistance to reducing acids (e.g., hydrochloric acid) under controlled conditions.
Excellent choice for chemical reactors, tanks, and piping handling aggressive fluids.
5. Limitations
Like other austenitic stainless steels, 317L can be susceptible to:
Stress corrosion cracking (SCC) in hot chloride solutions
Localized attack in highly acidic or strongly reducing environments
6. Applications Related to Corrosion Resistance
Chemical and petrochemical equipment
Marine and seawater-exposed components
Food and pharmaceutical processing machinery
Heat exchangers, piping, and storage tanks
Summary
317L stainless steel provides excellent overall corrosion resistance, with superior performance in chloride-rich and oxidizing environments due to its high molybdenum content and low carbon. Its combination of corrosion resistance, weldability, and formability makes it ideal for chemical, marine, pharmaceutical, and industrial applications.
Cold Working
Cold Working of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel that exhibits good ductility and formability, making it suitable for a variety of cold working operations. Cold working increases strength through work hardening while retaining corrosion resistance.
1. Common Cold Working Processes
Bending and Forming: Can be shaped into complex geometries for tanks, piping, and structural components.
Rolling: Suitable for sheets, strips, and coils.
Deep Drawing: Can produce containers, trays, and intricate components.
Stamping and Punching: Used in chemical, marine, and industrial applications.
2. Work Hardening
317L work hardens rapidly, increasing tensile and yield strength during deformation.
Excessive cold working can reduce ductility.
Intermediate annealing is recommended for extensive forming to restore ductility and relieve internal stresses.
3. Fabrication Considerations
Use gradual deformation to avoid cracking or overstressing the material.
Proper tooling, lubrication, and support are essential for maintaining surface finish and dimensional accuracy.
Cold-worked components may require stress relief for critical applications.
4. Applications Related to Cold Working
Chemical and petrochemical processing equipment
Marine components exposed to seawater
Food and pharmaceutical processing machinery
Tanks, piping, and structural parts requiring corrosion resistance
Summary
317L stainless steel exhibits excellent cold working characteristics, allowing bending, rolling, deep drawing, and stamping. Cold working enhances strength while maintaining corrosion resistance, making 317L ideal for chemical, marine, pharmaceutical, and industrial applications.
Heat Treatment
Heat Treatment of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel. Its strength is primarily derived from its austenitic structure and work hardening, so it is not hardenable by conventional heat treatment methods. Heat treatment is mainly used for annealing, stress relief, and restoring ductility after cold working or welding.
1. Annealing
Purpose: Restore ductility, relieve stresses, and improve corrosion resistance after cold working or welding.
Typical temperature: 1040–1120°C (1900–2050°F).
Cooling method: Rapid cooling, typically in air or water, to maintain corrosion resistance.
2. Stress Relief
Applied to reduce internal stresses from forming, welding, or machining.
Temperature range: 450–650°C (840–1200°F).
Ensures dimensional stability and reduces risk of distortion or cracking.
3. Effects of Heat Treatment
Restores ductility and toughness in heavily cold-worked areas.
Eliminates residual stresses from welding or fabrication.
Does not significantly increase strength, as 317L is not precipitation-hardenable.
4. Post-Treatment Surface Finishing
Pickling or passivation may be applied after heat treatment to remove oxides and restore the protective chromium oxide layer for optimal corrosion resistance.
5. Applications Related to Heat Treatment
Welded piping, tanks, and vessels in chemical processing
Heat exchangers and reactors requiring dimensional stability
Marine and pharmaceutical equipment exposed to high temperatures
Summary
Heat treatment of 317L stainless steel is used primarily for annealing and stress relief, maintaining ductility, corrosion resistance, and dimensional stability. It ensures reliable performance in chemical, marine, pharmaceutical, and industrial applications, especially after fabrication or welding.
Heat Resistance
Heat Resistance of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel with good resistance to oxidation and scaling at elevated temperatures. Its chemical composition allows it to maintain corrosion resistance and mechanical integrity in moderately high-temperature applications.
1. Continuous Service Temperature
Suitable for continuous service up to approximately 870°C (1600°F) in oxidizing atmospheres.
Maintains mechanical strength and corrosion resistance under sustained heat exposure.
2. Intermittent Exposure
Can withstand short-term or intermittent exposures up to 925°C (1700°F) without significant scaling or oxidation.
Suitable for components exposed to thermal cycling or fluctuating high temperatures.
3. Oxidation Resistance
Forms a stable chromium oxide layer that protects against scaling and oxidation.
High molybdenum content enhances resistance to localized attack during high-temperature exposure.
4. Limitations
Not suitable for prolonged service at extremely high temperatures (>925°C / 1700°F).
May be susceptible to crevice or stress corrosion cracking in hot chloride-containing environments.
5. Applications Related to Heat Resistance
Heat exchangers, boilers, and furnace components in chemical and petrochemical industries
High-temperature piping and tanks
Marine equipment exposed to elevated temperatures
Industrial equipment requiring moderate heat resistance combined with corrosion resistance
Summary
317L stainless steel provides good heat resistance for continuous service up to 870°C and intermittent exposure up to 925°C, while maintaining corrosion resistance and mechanical integrity. Its combination of heat resistance, corrosion resistance, and weldability makes it suitable for chemical, marine, pharmaceutical, and industrial applications.
Hot Working
Hot Working of 317L Stainless Steel
317L stainless steel is a low-carbon, high-molybdenum austenitic stainless steel with good hot workability. Hot working allows shaping and forming at elevated temperatures while minimizing work hardening and maintaining mechanical integrity.
1. Hot Working Temperature
Recommended hot working range: 1150–900°C (2100–1650°F).
Proper temperature control prevents grain growth and preserves corrosion resistance and strength.
2. Hot Working Processes
Hot Rolling: Produces sheets, plates, and strips with uniform thickness.
Forging: Suitable for structural components and high-temperature parts.
Extrusion: Enables production of rods, tubes, and profiles.
Hot Pressing and Forming: Useful for shaping complex geometries with minimal risk of cracking.
3. Advantages of Hot Working
Reduces work hardening compared to cold working.
Improves ductility and toughness in the finished component.
Facilitates the production of large, thick, or complex parts.
4. Post-Hot Working Treatments
Annealing may be applied to restore uniform mechanical properties and relieve residual stresses.
Pickling or passivation improves surface corrosion resistance after hot working.
5. Applications Related to Hot Working
Heat exchangers, furnace components, and high-temperature piping
Structural components for petrochemical and power generation equipment
Industrial parts requiring high-temperature performance and corrosion resistance
Summary
317L stainless steel exhibits excellent hot working characteristics, allowing rolling, forging, extrusion, and complex forming at 1150–900°C. Hot working reduces work hardening, enhances ductility, and enables the production of parts for chemical, marine, pharmaceutical, and industrial high-temperature applications.
