317L stainless steel plate for projects that require elevated resistance to pitting, crevice corrosion, and certain industrial acids while keeping fabrication and welding costs moderate. For 2025 procurement, buyers should expect wide regional price variation driven by molybdenum and nickel markets, local alloy surcharges, and supply-chain premiums; typical merchant ranges run from roughly USD $800–4,000 per tonne, depending on origin, form, thickness, and certificate level.

what is 317L

317L (UNS S31703) is an austenitic chromium-nickel-molybdenum stainless alloy with low carbon content intended to reduce carbide precipitation during welding and high molybdenum for improved resistance to pitting and crevice corrosion. It typically meets ASTM A240 / ASME SA-240 specifications for stainless plate and sheet. Typical elemental ranges include chromium 18–20%, nickel 11–15%, and molybdenum 3–4% with carbon ≤0.03%.

Chemical composition and standards

We hold to the reference composition used by mills and stockists. The commonly cited composition window for 317L includes:

• Chromium (Cr): ~18.0–20.0%

• Nickel (Ni): ~11.0–15.0%

• Molybdenum (Mo): ~3.0–4.0%

• Manganese (Mn): ≤2.0%

• Silicon (Si): ≤1.0%

• Carbon (C): ≤0.03% (the “L” grade meaning low carbon)

• Phosphorus, Sulfur: trace levels per specification limits

Meeting ASTM A240/ASME SA-240, mills provide material test certificates (MTCs) and traceability for every heat. The low carbon helps prevent chromium carbide precipitation at grain boundaries during welding, preserving corrosion resistance near welds.

Mechanical and physical properties

Typical, mill-certified figures (for annealed plate) fall in these practical ranges; engineers should request certified values for design:

• Tensile strength (ultimate): ~520–720 MPa (varies by thickness and finish)

• Yield strength (0.2% offset): ~200–350 MPa

• Elongation (in 50 mm): ≥30% for many sheet/plate conditions

• Hardness (HRB/HRC): low to moderate in annealed condition

Thermal behavior: 317L is stable to moderately high service temperatures; continuous use up to ~600°C is common, but prolonged exposure at 400–800°C may promote sensitization in non-L grades, which 317L mitigates due to low carbon. For pressure-vessel design and structural calculations use the manufacturer’s certified mechanical data.

Corrosion performance — where 317L shines and where it does not

317L is chosen when chloride pitting and crevice corrosion resistance is important and when sulfuric or phosphoric acid exposure occurs. Molybdenum content improves resistance to localized attack compared with 304/316 families. In many chemical processing and marine environments 317L performs better than 316/316L, particularly in more aggressive chloride-containing streams. Nevertheless, strongly oxidizing acids (for example concentrated nitric acid) can attack austenitic stainless steels and may require alternative alloys. Consider pitting resistance equivalent number (PREN) or published corrosion charts for quantitative comparisons.

Fabrication, welding and heat treatment notes

We advise the following practical steps when specifying or fabricating 317L plate:

• Forming: Typical cold and hot forming methods apply. Because of good ductility, bending and deep drawing are straightforward within recommended bend radii for thickness.

• Welding: Use matching or low-carbon filler (ER317L, ER317LM) for best corrosion performance near welds. Preheating is rarely required for thin plate, though joint geometry and weld heat input should be controlled. Post-weld annealing is seldom necessary for the “L” grade; pickling and passivation after welding remove heat tint and restore passive film.

• Cutting: Laser, plasma, or waterjet cutting work well. For high precision or to avoid heat-affected zone (HAZ) discoloration use waterjet or fine laser settings.

• Stress relief / Annealing: General practice is full anneal followed by water quench at the producing mill. For service at elevated temperatures refer to supplier guidance.

Typical applications and sectors

317L’s place is in industries where chemical attack, chloride content, or sulfide exposure threaten lesser grades. Common uses include:

• Chemical and petrochemical equipment (reactors, heat exchangers, piping).

• Flue gas desulfurization and air pollution control where acidic condensates occur.

• Pharmaceutical and food processing lines where corrosion resistance and cleanability matter.

• Pulp and paper equipment subject to sulfate environments.

• Marine fittings and seawater handling items when higher pitting resistance is demanded.

We recommend specifying 317L only after verifying medium, temperature, and concentration limits with corrosion testing data or supplier guidance.

Market drivers that control 2025 pricing

Price formation for 317L plate is not a single figure. We track several drivers that buyers must include in any landed cost estimate:

1. Base metal commodity prices: Nickel, molybdenum, chromium prices set raw-material cost. Molybdenum in particular exerts strong leverage on 317/317L pricing.

2. Alloy surcharges: Mills and service centers apply monthly alloy surcharges that track LME metal indices or proprietary baskets. In Europe and North America buyers often see regular surcharge updates.

3. Form factor and processing: Plate vs coil vs sheet, thickness, finish, and required MTC levels change price significantly. Heavy plate or certified pressure-vessel plate costs more per tonne than thin commercial sheet.

4. Order size and terms: MOQ, batch size, and shipping Incoterms (FOB, CFR, CIF) influence quotes.

5. Lead time and supply tightness: Short-lead or emergency orders attract premiums.

6. Regional freight, duties, and taxes: Import duty, VAT or GST, and logistics add to landed price.

Global price comparison — indicative merchant ranges (2025)

Below we present an indicative, comparative snapshot of merchant ranges for 317L stainless steel plate in 2025. These ranges represent merchant/distributor and FOB listings, not a firm contractual price. Buyers must request quotes for a precise figure.

How to use the table: Treat the numbers as an initial benchmark. For formal procurement run a request for quotation (RFQ) that specifies thickness, plate finish, MTC level, test requirements, and Incoterm.

Interpreting supplier quotations (practical checklist)

When reviewing a quote for 317L plate we recommend verifying the following fields; ticking them off prevents costly misunderstandings:

• Mill standard and spec (ASTM A240 / ASME SA-240)

• UNS / grade notation (UNS S31703)

• Finish and thickness tolerance (2B, No.1, BA, No.4, etc.)

• Certificate type (3.1/3.2 EN 10204, or mill MTC)

• Heat treatment and provenance (mill name, heat number)

• Chemical and mechanical test results included with shipment

• Delivery terms and expected lead time

• Surface protection and packaging for sea freight

• Warranty, return policy, and acceptance test plan (ATP)

Quality control, testing and documentation

We expect reputable suppliers to provide:

• Material Test Certificate (MTC) to EN 10204 3.1 or equivalent showing chemical and mechanical test results.

• Mill heat number traceability so the buyer or third party can verify production records.

• Non-destructive testing (NDT) where required (UT, PT, etc.).

• Corrosion testing: If used in critical service, insist on pitting potential or laboratory exposure test reports for the specific process fluid.

• Surface cleanliness: Passivation certificate and weld passivation/pickling record if items were welded or cut.

Logistics, packaging, and storage

For long sea transit we recommend banding, wooden crates, and waterproof wrapping. For thin plate sizes use interleaving paper or plastic, then timber-blocked crates. Avoid prolonged wet storage. Inland transport must maintain plate flatness; overstacking may introduce permanent bending.

Sustainability and recycling

317L is fully recyclable. Scrap value depends on nickel and molybdenum content; mills and recyclers pay premiums for segregated stainless scrap streams. When specifying, include any recycled content requirements only if mill can certificate percentage.

How we approach sourcing to control cost (practical strategy)

When we help clients source 317L plate, our process includes:

1. Define exact specification: thickness, finish, MTC level, tolerances.

2. Solicit competing RFQs: at least three quotes from different origins (China mill, regional distributor, local service center).

3. Normalize quotations: convert to same Incoterm, add estimated import duty and freight, and compare landed cost per tonne and unit.

4. Check alloy surcharge methodology: if surcharge tied to LME metals, compare recent history.

5. Assess lead time risk: long lead times add hidden cost; include contingency.

6. Sample or small pilot purchase: for new suppliers request a sample plate with full MTC prior to large order.

Limitations, caveats and what to verify with suppliers

We emphasize honesty: published ranges are indicative. Exact figures change with commodity markets, political events, freight disruptions, and local taxes. Always request recent MTCs, confirm mill finish and test reports, and ask suppliers to lock prices in writing for the quoted validity period.

Annex — practical specification template

When you send an RFQ include:

• Material: 317L (UNS S31703)

• Specification: ASTM A240 / ASME SA-240

• Thickness: __ mm (specify tolerance)

• Size: __ x __ mm (or cut-to-size with edge condition)

• Finish: 2B / No.1 / No.4 / BA / Mirror

• Certificate: EN 10204 3.1 / Mill MTC

• Mechanical tests required: Tensile, Yield, Elongation

• Chemical tests required: Full elemental analysis

• Packaging: Waterproof, banded, timber blocked

• Delivery: Incoterm: FOB / CIF / CFR

• Lead time required: __ weeks

Frequently asked questions (FAQs)

Q1 — How does 317L compare with 316L for seawater or chloride exposure?
We recommend 317L where chloride pitting risk is elevated. The extra molybdenum and slightly higher chromium and nickel content of 317/317L grants better resistance to localized attack than 316/316L in many chloride environments, but design must consider temperature, chloride concentration, and flow conditions. For aggressive seawater at elevated temperature duplex or superaustenitic alloys might be required.

Q2 — What certification should I insist on for pressure-containing parts made from 317L plate?
Ask for ASTM A240 / ASME SA-240 compliance and an EN 10204 3.1 (or 3.2 where needed) mill test certificate that shows heat number, chemical and mechanical test data, and any NDT reports. For critical service include an acceptance test plan that lists hydrostatic or leak tests if required.

Q3 — How quickly do prices change and what can I do to protect my project budget?
Prices follow metal markets and can move monthly or faster. Protect budgets by negotiating price validity windows, locking in fixed-price contracts where feasible, or using a staggered purchase plan to average price. Confirm alloy surcharge formulas in your purchase contract.

Q4 — Are there thickness bands where 317L is unusually more expensive?
Heavy plate with tight dimensional tolerances, thicker than ~20–25 mm, and plate requiring pressure-vessel certification typically pulls higher per-tonne premiums because of metallurgical control and lower production throughput. Cold-rolled thin gauge coil often costs less per tonne but may not be suitable for thick plate needs.

Q5 — Can we weld 317L plate to 316L or 304L in a mixed-grade assembly?
Yes, mixed-grade joints are common; choose compatible filler metal (usually matching the higher alloy, e.g., ER317L) and be mindful of galvanic or localized corrosion risks in the assembled environment. Post-weld pickling/passivation restores corrosion resistance near joints.