AISI 317LMN Stainless Steel Plate | 317LMN China steel mill-Direct Supply
What is AISI 317LMN Stainless Steel?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 317LMN Stainless Steel Plate.
AISI 317LMN (UNS S31726) is an advanced low-carbon austenitic stainless steel within the 317 family. It combines higher molybdenum content (typically 4.0–5.0%), intentional nitrogen addition, and extra-low carbon (maximum 0.03%). The elevated molybdenum significantly improves resistance to pitting and crevice corrosion in aggressive chloride environments. Nitrogen further increases strength through solid-solution hardening and contributes to a higher Pitting Resistance Equivalent Number (PREN), while the low carbon content ensures excellent resistance to intergranular corrosion after welding.
This combination makes AISI 317LMN particularly suitable for welded constructions in chemical processing, pulp and paper, flue gas desulfurization, offshore, pharmaceutical and other demanding chloride-containing applications where both enhanced corrosion resistance and higher mechanical strength are required.
SHH STEEL supplies AISI 317LMN as true China steel mill-Direct Supply, sourcing directly from major Chinese stainless steel mills. This model delivers competitive mill pricing, consistent quality, complete heat traceability and reliable delivery. SHH STEEL offers AISI 317LMN in plate and sheet form across a practical range of thicknesses and surface finishes.
AISI 317LMN is frequently compared with a240 317l, a240 317lm, a240 316l, a240 904l, a240 2205 and a240 316 when selecting materials for highly corrosive or higher-strength chloride service. SHH STEEL provides technical support to help customers choose the most appropriate grade.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 317LMN / UNS S31726 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, related high-Mo + N specs | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Solution Annealed | Standard |
| Thickness Range | 0.5 mm – 80 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 2000–3000 mm | Available |
| Length | Up to 12000 mm or cut-to-length | Available |
| Surface Finish | 2B, No.1, BA, No.4 | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
SHH STEEL can supply AISI 317LMN dual-certified to ASTM A240 / ASME SA240 when required by the project.
Chemical Composition
Typical Chemical Composition of AISI 317LMN (UNS S31726):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.030 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 17.00 – 20.00 |
| Nickel (Ni) | 13.50 – 17.50 |
| Molybdenum (Mo) | 4.00 – 5.00 |
| Nitrogen (N) | 0.10 – 0.20 |
| Iron (Fe) | Balance |
AISI 317LMN features three critical controls: higher molybdenum (4.0–5.0%) for enhanced pitting resistance, intentional nitrogen (0.10–0.20%) for increased strength and further improved PREN, and extra-low carbon (≤ 0.03%) for excellent weldability and intergranular corrosion resistance. SHH STEEL carefully controls all three elements to deliver consistent high-performance results.
Mechanical Properties
Annealed Condition (typical values)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 550 MPa |
| Yield Strength (0.2%) | ≥ 240 MPa |
| Elongation (in 50 mm) | ≥ 35–40% |
| Hardness | ≤ 217 HB |
AISI 317LMN offers higher yield and tensile strength than standard 317L and 317LM due to the nitrogen addition, while retaining good ductility and toughness. The higher strength can allow thickness reduction in many designs. SHH STEEL supplies material with consistent nitrogen-enhanced mechanical properties.
Physical Properties Density is approximately 8.00 g/cm³. The grade is non-magnetic in the annealed condition. Melting range is approximately 1370–1400°C.
Material Comparison
| Grade | Mo (%) | Nitrogen | Carbon | Strength Level | Pitting Resistance | Typical Preference |
|---|---|---|---|---|---|---|
| AISI 316L | 2.0–3.0 | Low | ≤ 0.03 | Lower | Better | Standard welded chloride service |
| AISI 317L | 3.0–4.0 | Low | ≤ 0.03 | Lower | Superior | Welded aggressive chloride service |
| AISI 317LM | 4.0–5.0 | Low | ≤ 0.03 | Lower | Higher | More severe chloride environments |
| AISI 317LMN | 4.0–5.0 | Elevated | ≤ 0.03 | Higher | Higher + PREN boost | High-strength severe chloride service |
| AISI 904L | 4.0–5.0 | Low | ≤ 0.02 | Standard | Excellent | Highly aggressive chloride / acid |
| AISI 2205 | 3.0–3.5 | Elevated | ≤ 0.03 | Much Higher | Excellent | High strength + high chloride resistance |
AISI 317LMN is selected when both enhanced pitting resistance (from higher Mo + N) and higher strength are required in aggressive chloride environments. Compared with a240 317l, it offers higher molybdenum, nitrogen strengthening and better overall performance. For maximum strength and chloride resistance, SHH STEEL also recommends evaluating duplex grades such as a240 2205.
Corrosion Resistance
AISI 317LMN offers excellent resistance to atmospheric corrosion and many chemical environments. The combination of higher molybdenum and nitrogen provides enhanced resistance to pitting and crevice corrosion in aggressive chloride-containing media, resulting in a higher PREN than standard 317L or 317LM. The low carbon content ensures excellent resistance to intergranular corrosion after welding.
It is particularly effective in chemical processing, pulp and paper, flue gas desulfurization, offshore and pharmaceutical applications. In extremely aggressive conditions involving high temperatures, very high chloride concentrations or strong reducing acids, more highly alloyed grades such as a240 904l or super duplex may still be necessary. SHH STEEL can assist in material selection based on the specific service environment.
Weldability
AISI 317LMN has excellent weldability due to its low carbon content. Matching or appropriate higher-molybdenum / nitrogen-bearing filler metals are recommended. The extra-low carbon minimizes the risk of intergranular corrosion in the as-welded condition, and post-weld annealing is generally not required.
The nitrogen content contributes to higher strength in both the base metal and the weld zone when proper procedures are followed. SHH STEEL recommends controlled welding parameters and post-weld cleaning to achieve optimum corrosion and mechanical performance.
Heat Treatment
AISI 317LMN is normally supplied in the solution-annealed condition by SHH STEEL.
Recommended solution annealing temperature range is 1010–1120°C, followed by rapid cooling. Proper solution annealing is important to retain nitrogen in solid solution and to optimize both strength and corrosion resistance. SHH STEEL controls heat treatment to ensure consistent performance.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 317LMN 2B – most common for general fabrication |
| No.1 | Hot-rolled, annealed and pickled | AISI 317LMN No.1 – industrial plate |
| BA | Bright Annealed | AISI 317LMN BA – cleaner surface applications |
| No.4 | Brushed finish | AISI 317LMN No.4 – architectural surfaces |
SHH STEEL regularly supplies AISI 317LMN in 2B and No.1 finishes, and can provide other finishes according to project requirements.
Tolerances
Dimensional tolerances for AISI 317LMN Stainless Steel Plate supplied by SHH STEEL generally conform to ASTM A480 practices.
Typical available size range is thickness 0.5 mm – 80 mm, width up to 2000–3000 mm, and length up to 12000 mm or cut-to-length. SHH STEEL provides precise dimensional control and can support tighter tolerances when required.
Equivalent Material Grades
| Grade / Designation | Standard / Region | Notes |
|---|---|---|
| AISI 317LMN | — | — |
| UNS S31726 | Unified Numbering System | — |
| ASTM A240 Type 317LMN | ASTM A240 | When dual certified |
| Related high-Mo + N grades | EN (Europe) | Closest European grades |
| Related SUS grades | JIS (Japan) | Japanese related grades |
| Related high-Mo + N grades | GB/T (China) | Chinese related grades |
| Related 317L / 317LM / 904L | Multiple | Lower-Mo / non-N / higher-alloy variants |
Related grades for comparison include a240 317l, a240 316l, a240 904l, a240 2205, a240 316 and a240 317.
Applications
AISI 317LMN is selected for welded constructions requiring both enhanced pitting resistance and higher strength in aggressive chloride environments. Typical applications of AISI 317LMN include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Chemical & Process Industry | AISI 317LMN tanks, vessels, reactors, piping and process equipment |
| Pulp & Paper | AISI 317LMN process equipment and structural parts |
| Flue Gas Desulfurization | AISI 317LMN components in FGD systems |
| Marine & Offshore | AISI 317LMN high-strength components in aggressive chloride environments |
| Pharmaceutical & Medical | AISI 317LMN clean equipment, vessels and piping |
| Pressure Vessels | AISI 317LMN higher-strength pressure vessels and containers |
| General Fabrication | AISI 317LMN welded tanks, frames and structures |
SHH STEEL supplies AISI 317LMN for these demanding applications with consistent quality. For related industry solutions, see our petrochemical industry, marine industry and equipment manufacturing pages. Supporting services include steel cutting services and steel welding services.
Why Choose SHH STEEL
SHH STEEL is a China steel mill-Direct Supply specializing in stainless steel plate and sheet. By working directly with major Chinese stainless steel mills, SHH STEEL supplies AISI 317LMN with the following advantages:
- Genuine China steel mill-Direct Supply pricing
- Consistent quality and complete heat traceability
- Full Mill Test Certificates (EN 10204 3.1)
- Higher-molybdenum + nitrogen-strengthened material optimized for severe chloride service and higher strength
- Flexible dimensions and surface finishes (including AISI 317LMN 2B and AISI 317LMN No.1)
- Technical support for selection among 317L, 317LM, 317LMN, 904L and duplex grades
- Value-added services including steel cutting services, steel welding services and worldwide shipping service
For more information about our company and full product range, please visit China steel Mill Agent-SHH STEEL.
FAQ
- What is the main difference between AISI 317LMN and AISI 317L or 317LM?AISI 317LMN adds intentional nitrogen on top of higher molybdenum and low carbon. This increases strength and further improves pitting resistance (higher PREN). SHH STEEL recommends 317LMN when both higher strength and enhanced chloride resistance are required.
- How does nitrogen improve AISI 317LMN?Nitrogen increases yield and tensile strength through solid-solution hardening and contributes to a higher Pitting Resistance Equivalent Number. It also helps stabilize the austenitic structure. SHH STEEL controls nitrogen content carefully for consistent performance.
- Is AISI 317LMN suitable for welded constructions?Yes. The low carbon content (≤ 0.03%) provides excellent resistance to intergranular corrosion after welding. SHH STEEL recommends 317LMN for most welded applications in aggressive chloride service.
- Is AISI 317LMN magnetic?Non-magnetic in the annealed condition. It may become slightly magnetic after heavy cold working. SHH STEEL supplies fully annealed material as standard.
- What is the density of AISI 317LMN?Approximately 8.00 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Can AISI 317LMN replace duplex stainless steels?In many corrosive chloride environments it can be a good alternative, but duplex grades such as 2205 offer significantly higher strength. SHH STEEL can help evaluate the best balance of corrosion resistance, strength and cost for your project.
- Does SHH STEEL supply dual-certified ASTM A240 / AISI 317LMN material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 317LMN Stainless Steel Plate is a low-carbon, nitrogen-strengthened, higher-molybdenum austenitic grade that successfully combines enhanced resistance to pitting and crevice corrosion with higher mechanical strength. It is an outstanding choice for welded chemical processing equipment, pulp and paper systems, flue gas desulfurization components, offshore structures and other applications in aggressive chloride environments where both superior corrosion performance and elevated strength are required.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 317LMN Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 317LMN 2B and AISI 317LMN No.1), or a competitive quotation.
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