# 317L / UNS S31703 Open-Die Forgings

**Jiangyin Jiangnan Metal Co., Ltd. forges UNS S31703 (317L) as seamless rolled rings, forged rings, flanges, shafts, discs, tube sheets, sleeves and bars to ASTM A182 Grade F317L, at its integrated melting and forging works in Zhouzhuang Town, Jiangyin City, Jiangsu Province, China.**

UNS S31703 is the low-carbon version of 317: a molybdenum-bearing austenitic stainless steel with 18 to 20 percent chromium, 11 to 15 percent nickel and 3 to 4 percent molybdenum. The pitting resistance equivalent is about 29.7, against 24.2 for 316 and 19.0 for 304. The 0.030 percent carbon ceiling keeps the grade free of sensitisation after welding.

Source page: https://www.steelforgepieces.com/Stainless-Steel/UNS-S31703.html

## Grade identity

| Field | Value |
|---|---|
| UNS number | S31703 |
| Common names | 317L, AISI 317L, Alloy 317L |
| Werkstoff number | 1.4438 |
| Forging specification | ASTM A182 / A182M Grade F317L |
| Plate specification | ASTM A240, ASME SA 240 |
| Type | Austenitic Cr-Ni-Mo stainless, low carbon |
| PREN, typical analysis | approx. 29.7 |
| Magnetic response | Non-magnetic when annealed |
| Hardening | Not hardenable by heat treatment; cold work only |

## Chemical composition, weight percent

| Element | Range |
|---|---|
| Chromium | 18.0 to 20.0 |
| Nickel | 11.0 to 15.0 |
| Molybdenum | 3.0 to 4.0 |
| Carbon | 0.030 max |
| Manganese | 2.00 max |
| Silicon | 1.00 max (A182), 0.75 max (A240) |
| Phosphorus | 0.045 max |
| Sulphur | 0.030 max |
| Nitrogen | 0.10 max |
| Iron | Balance |

## Mechanical properties

Forgings are accepted against ASTM A182 F317L, not against the ASTM A240 plate values that most 317L data sheets quote. Both are shown.

| Property | ASTM A182 F317L, forgings | ASTM A240, plate | Typical annealed |
|---|---|---|---|
| Tensile strength, min | 70 ksi / 485 MPa | 75 ksi / 515 MPa | 86,300 psi / 595 MPa |
| Yield strength 0.2 percent, min | 25 ksi / 170 MPa | 30 ksi / 205 MPa | 37,700 psi / 260 MPa |
| Elongation in 2 in. or 4D, min | 30 % | 40 % | 55 % |
| Reduction of area, min | 50 % | not specified | not specified |
| Hardness, max | not specified | 95 HRB | 85 HRB |
| Modulus of elasticity | 200 GPa / 29.0 x 10^6 psi | | |
| Poisson's ratio | 0.27 to 0.30 | | |

The typical column is measured data from wrought material, not an acceptance criterion. On a heavy forging the result depends on section size, reduction ratio under the press, and test coupon orientation.

## Physical properties

| Property | Metric | Imperial |
|---|---|---|
| Density | 7.89 g/cm3 | 0.285 lb/in3 |
| Melting range | 1390 to 1440 C | 2540 to 2630 F |
| Specific heat, 0 to 100 C | 502 J/kg·K | 0.12 BTU/lb·F |
| Thermal conductivity at 20 C | 14 W/m·K | 8.1 BTU/hr·ft·F |
| Electrical resistivity at 20 C | 85.1 microohm·cm | 33.5 microohm·in |
| Thermal expansion, 20 to 100 C | 16.2 x 10^-6 /C | 8.9 x 10^-6 /F |

## Corrosion resistance

PREN = Cr + 3.3Mo + 16N, computed from mid-range typical analyses.

| Grade | Cr % | Mo % | N % | PREN |
|---|---|---|---|---|
| 304 | 18.0 | none | 0.06 | 19.0 |
| 316 | 16.5 | 2.1 | 0.05 | 24.2 |
| 317L | 18.5 | 3.1 | 0.06 | 29.7 |
| 6Mo superaustenitic | 20.5 | 6.2 | 0.22 | 44.5 |

Suited to sulphuric, acidic chloride and phosphoric acid duty, hot organic and fatty acids, flue gas desulphurisation, and pulp and paper bleach plant. Not suited to strongly oxidising acids such as nitric, where molybdenum-free grades perform better. Chloride stress corrosion cracking remains possible; above roughly 60 C in chloride service, consider duplex (A182 F51) or 6Mo (A182 F44).

## Manufacture at Jiangyin Jiangnan Metal

**Melting.** 317L runs the stainless route: 25 t electric arc furnace, 25 t or 50 t ladle furnace, 30 t or 60 t vacuum oxygen decarburisation. Maximum heat size 60 tonnes. Electroslag remelting available on 3 t and 6 t protective-atmosphere furnaces.

**Forging.** Hydraulic open-die presses of 6,300 t, 4,000 t and 2,000 t; hammers of 5 t, 3 t, 2 t, 1 t and 750 kg; radial-axial ring mills of 6 m, 3 m and 1 m.

**Solution annealing.** 1010 to 1121 C (1850 to 2050 F) with rapid cooling. Where hot working finishes below the minimum working temperature, 1080 to 1180 C with a quench. 14 furnaces including two 15 m well-type furnaces for vertical quenching of long shafts.

**Machining.** Vertical lathes to 5,000 mm swing, horizontal lathes to 14 m between centres, deep-hole drilling to 1,600 mm diameter by 10,000 mm. The grade work-hardens quickly: low speed, constant uninterrupted feed, chip breakers advised.

**Welding.** AWS E317L or ER317L filler. No post-weld heat treatment required. Do not use oxyacetylene.

### Size envelope

| Product | Limit |
|---|---|
| Seamless rolled rings | OD 50 to 6,000 mm |
| Forged shafts | to 14,000 mm turned length |
| Discs, tube sheets, blocks | to 5,000 mm machined diameter |
| Bored cylinders, hollow shafts | to 1,600 mm dia x 10,000 mm |
| Single piece weight | 10 kg to 30,000 kg |

## Product forms in 317L

Seamless rolled rings, forged rings, retaining rings and valve seat rings. Forged flanges, tube sheets, covers and nozzles. Round bars, shafts, spindles and eccentric shafts. Discs, blanks, gear blanks and wheels. Sleeves, bushings, hollow bars and bored cylinders. Valve bodies, bonnets, blocks, stems and spools. Blocks, rolls, manifolds and custom profiles to drawing.

Supplied as-forged with machining allowance, proof-machined for volumetric inspection, or finish-machined to drawing.

## Testing and certification

| Test | Standard | Where |
|---|---|---|
| Optical emission spectrometry | ASTM E415 | In house |
| Carbon and sulphur, infrared | ASTM E1019 | In house |
| Positive material identification | PMI | In house |
| Tensile | ASTM A370, ISO 6892 | In house, 600 kN and 300 kN |
| Charpy V-notch impact | ASTM A370, to -60 C | In house |
| Ultrasonic examination | ASTM A388, EN 10228-3 | In house |
| Grain size | ASTM E112 | In house |
| Intergranular corrosion | ASTM A262, ASTM G28 | Accredited third-party laboratory |
| Pitting resistance | ASTM G48 | Accredited third-party laboratory |

Classification society approvals: CCS, BV, DNV, LR, NK. EN 10204 3.1 as standard; EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TUV or the customer's inspector on request. Traceability runs from melt number to despatch.

## Ordering

Minimum order 10 kg, no minimum piece count. Lead time 20 to 60 days. Include in the enquiry: grade and specification; dimensions or drawing; quantity and repeat volume; delivery condition; heat treatment and testing requirements; certification and destination port.

## Frequently asked questions

### What is the difference between 317L and 316L?
Molybdenum and nickel. 317L carries 3.0 to 4.0 percent molybdenum against roughly 2 percent in 316L, and 11.0 to 15.0 percent nickel. PREN rises from about 24.2 to about 29.7, giving better resistance to chloride pitting, crevice attack and sulphurous media. Both share the 0.030 percent carbon ceiling, so both can be used as welded.

### What are the ASTM A182 F317L mechanical minimums?
70 ksi (485 MPa) tensile, 25 ksi (170 MPa) yield at 0.2 percent offset, 30 percent elongation in 2 in. or 4D, 50 percent reduction of area. The ASTM A240 plate minimums of 75 ksi, 30 ksi and 40 percent do not apply to forgings.

### Can UNS S31703 be hardened by heat treatment?
No. It is fully austenitic and hardens only by cold work. Non-magnetic when annealed.

### Does 317L need post-weld heat treatment?
No. The 0.030 percent carbon maximum prevents chromium carbide precipitation during welding. Use AWS E317L or ER317L filler; avoid oxyacetylene welding.

### What is the solution annealing temperature?
1010 to 1121 C (1850 to 2050 F) with rapid cooling, or 1080 to 1180 C with a quench where hot working finished below the minimum working temperature.

### Is 317L suitable for nitric acid?
Usually not. Molybdenum-bearing grades generally perform worse than molybdenum-free grades in strongly oxidising acids.

### What size 317L forgings can you produce?
Rings to OD 6,000 mm, single pieces to 30 tonnes, shafts to 14,000 mm turned length, discs to 5,000 mm diameter. Minimum order 10 kg.

### Do you melt the 317L yourselves?
Yes. 25 t electric arc furnace, 25 t and 50 t ladle furnaces, 30 t and 60 t vacuum oxygen decarburisation units. The certificate traces to a melt number, not to a purchased billet.

### What certification is supplied?
EN 10204 3.1 as standard, EN 10204 3.2 witnessed on request. Works approvals: CCS, BV, DNV, LR, NK.

## Related grades forged at this works

A182 F44 (6Mo), A182 F51 (duplex 2205), 904L, A182 F347, Alloy 20, Incoloy 825.

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**Jiangyin Jiangnan Metal Co., Ltd.**
Integrated steel melting works, open-die forge and ring rolling mill. Operating since 1997. 460 staff including 9 senior engineers, 32 intermediate engineers and 140 technicians.

No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Hours: Monday to Saturday, 08:00 to 17:30 China Standard Time (UTC+8)

Technical data compiled from ASTM A182 / A182M Grade F317L, ASTM A240 / ASME SA 240 and published Alloy 317L mill data sheets. Last updated 7 October 2026.