Stainless Steel 317LMN CR-2B
Finish state
AISI/SAE 317LMN · UNS S31726 · EN 1.4439, X2CrNiMoN17-13-5
Thin sheet/coil (0.5–6 mm) with smooth 2B finish for tank linings, plate heat exchangers and formed parts.
Values for the CR-2B condition
Other 317LMN tempers and conditions
317LMN is listed in 4 conditions; see the grade overview at 317LMN.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed (~1050–1120 °C, rapid quench), pickled | Standard supply condition for plate, sheet, bar, pipe and fittings; maximum corrosion resistance and ductility. | 340 | 620 | 45 | 165 HB | — |
As-welded deposit | Reference condition for fabricated vessels; strength is governed by the weld, and over-alloyed filler (e.g. ERNiCrMo-3) is used to match the base metal's pitting resistance. | 350 | 590 | 33 | 180 HB | 2 % IACS |
CR-2BThis page cold rolled, annealed, pickled and lightly skin-passed sheet | Thin sheet/coil (0.5–6 mm) with smooth 2B finish for tank linings, plate heat exchangers and formed parts. | 355 | 640 | 44 | 175 HB | 2 % IACS |
Cold drawn | Choose for higher strength shafts, fasteners and machined fittings where corrosion resistance of the L+N grade is still needed. | 550 | 760 | 25 | 220 HB | — |
What is 317LMN CR-2B?
317LMN CR-2B is 317LMN supplied in the CR-2B condition — thin sheet/coil (0.5–6 mm) with smooth 2B finish for tank linings, plate heat exchangers and formed parts. 317LMN CR-2B has a yield strength of 355 MPa (51.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of stainless steel grades. Elongation at break is 44% and the elastic modulus is 200 GPa (29 Msi). 317LMN CR-2B has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F). Annealed is the default condition FabDigit quotes; CR-2B is available on request or by drawing note.
Advantages
- Good corrosion resistance — 80/100, better than 88% of stainless steel grades
- Forms and bends easily — 72/100, better than 84% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
317LMN CR-2B properties
Typical room-temperature values for 317LMN CR-2B; 23 are specific to this condition. Other listed values are 317LMN reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
317LMN CR-2B has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical14
317LMN CR-2B has a yield strength of 355 MPa (51.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of stainless steel grades. Elongation at break is 44% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
317LMN CR-2B is rated for continuous service to 425°C (797 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
317LMN CR-2B conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 88% of stainless steel grades.
Sustainability4
Producing a kilogram of 317LMN CR-2B takes about 58 MJ of energy and emits 5.5 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
317LMN CR-2B's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability very good (80/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 317LMN CR-2B
Is 317LMN easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, 30–60 % lower speed than 304, heavy feed and copious flood coolant to avoid glazing.
Can 317LMN be welded?
Readily welded by GTAW/GMAW/SMAW without pre- or post-weld heat treatment; use over-alloyed filler (317L/Mo-rich, ERNiCrMo-3/-4) to keep weld-metal PREN at base-metal level, keep heat input low and interpass < 150 °C.
Can 317LMN be formed, bent or molded?
Cold forms well but needs ~40–50 % more press force and larger springback allowance than 316L; hot work 1150–900 °C followed by full solution anneal and quench.
What surface finishes work on 317LMN?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; no anodising — mechanical polishing to No.4/mirror is straightforward.
317LMN chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow-carbon grade | ≤ 0.03 | 0.02 |
| Si | ≤ 0.75 | 0.4 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0 |
| CrEN 1.4439: 16.5–18.5 | 17 – 20 | 18.5 |
| NiEN 1.4439: 12.5–14.5 | 13.5 – 17.5 | 14.5 |
| Mo | 4 – 5 | 4.3 |
| NEN 1.4439: 0.12–0.22 | 0.1 – 0.2 | 0.15 |
| Cu | ≤ 0.75 | 0.3 |
| Fe | balance | — |
317LMN CR-2B — frequently asked
What is 317LMN CR-2B used for?
317LMN CR-2B is typically used for FGD systems, chemical process equipment and offshore hardware. In short: nitrogen-strengthened 317 grade; highest PREN in 317 family; below 6Mo superaustenitics.
What is the yield strength of 317LMN CR-2B?
317LMN CR-2B has a typical yield strength of 355 MPa (51.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 317LMN CR-2B easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, 30–60 % lower speed than 304, heavy feed and copious flood coolant to avoid glazing.
Can 317LMN CR-2B be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW without pre- or post-weld heat treatment; use over-alloyed filler (317L/Mo-rich, ERNiCrMo-3/-4) to keep weld-metal PREN at base-metal level, keep heat input low and interpass < 150 °C.
What surface finishes work on 317LMN CR-2B?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; no anodising — mechanical polishing to No.4/mirror is straightforward.
Can 317LMN CR-2B be formed, bent or molded?
Cold forms well but needs ~40–50 % more press force and larger springback allowance than 316L; hot work 1150–900 °C followed by full solution anneal and quench.
What is the maximum service temperature of 317LMN CR-2B?
317LMN CR-2B is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 317LMN Annealed and 317LMN-CD?
Annealed is the default condition — standard supply condition for plate, sheet, bar, pipe and fittings; maximum corrosion resistance and ductility. CD: choose for higher strength shafts, fasteners and machined fittings where corrosion resistance of the L+N grade is still needed. Yield strength is 340 MPa in Annealed versus 550 MPa in CD.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip (S31726) — ASTM International (2023)
- ASTM A182 / A312 / A276 (S31726 forgings, pipe, bar) — ASTM International (2022)
- EN 10088-1/-2 — Stainless steels: X2CrNiMoN17-13-5 (1.4439) — CEN (2014)
- GB/T 24511 / GB/T 4237 (022Cr19Ni13Mo4N ) — SAC (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Outokumpu Steel Grades / Corrosion Handbook (317LMN, 4439) — Outokumpu (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.