F6NM (UNS S41500 / AISI 415) is a low-carbon soft martensitic stainless steel containing ~13% Cr, 4% Ni, and 0.5% Mo. Compared with conventional 13Cr grades (410 / 420), its higher Ni and near-zero C deliver superior sub-zero toughness, better weldability, and improved resistance to SSC and pitting. Qualified to NACE MR0175/ISO 15156; service range −60 °C to 300 °C. Primary sectors: oil & gas, hydropower, petrochemical, marine, power generation.
Equivalent Grades
| System | Designation | Specification(s) |
|---|---|---|
| ASTM / ASME / UNS | F6NM · S41500 · AISI 415 · CA6-NM | A182, A240, A276, A473, A479 |
| EN / DIN | 1.4313 · X3CrNiMo13-4 | EN 10088-3 · EN 10222-5 |
| JIS | SCS5 · SUSF415 · SUS 415 | JIS G4305 |
| AFNOR | Z4CND13.4M · Z6CND13-04 | NF A35-574 |
| BS | 425C11 · 415S17 | BS EN 10028 |
Applications
| Industry | Parts / Components |
|---|---|
| Oil & Gas | Valve bodies, gate valves, valve seats & gates, pump shafts, compressor discs, wellhead housings, Christmas tree components, flanges, tubulars |
| Hydropower | Turbine runners, turbine blades, turbine casings, hydraulic turbine shafts |
| Power Generation | Reactor pressure vessels, boiler fittings, pump impellers, forged nozzles |
| Marine / Subsea | Propeller shafts, hull reinforcements, subsea actuators, riser clamps |
| Chemical / Petrochem | Centrifuges, heat exchangers, compressor impellers, reactor vessels |
Supply Forms & Dimensions
| Form | Key Standard | Typical Size |
|---|---|---|
| Round Bar | ASTM A276 · A479 | Ø 10–800 mm |
| Flat Bar | ASTM A276 | t ≥ 5 mm, custom width |
| Plate / Sheet | ASTM A240 · ASME SA240 | t 1–200 mm |
| Seamless Pipe / Tube | ASTM A213 · A312 | Custom OD / WT |
| Wire / Wire Rod | ASTM A580 | Ø 0.1–13 mm |
| Forging (ring / disc / shaft) | ASTM A182 · A473 | Custom |
Chemical Composition
Per ASTM A182 / A240 (UNS S41500), heat analysis, wt%:
| C | Cr | Ni | Mo | Mn | Si | P max | S max |
|---|---|---|---|---|---|---|---|
| ≤ 0.05 | 11.5–14.0 | 3.50–5.50 | 0.50–1.00 | 0.50–1.00 | ≤ 0.60 | 0.030 | 0.030 |
Mechanical Properties
Per ASTM A182 / A479, SA+DT condition, minimum values:
| Condition | UTS (MPa) | YS (MPa) | El. (%) | RA (%) | Hardness | CVN |
|---|---|---|---|---|---|---|
| Q+T (standard) | ≥ 795 | ≥ 620 | ≥ 15 | ≥ 40 | 22–28 HRC | > 27 J @ −46 °C |
| NACE sour service | ≥ 700 | ≥ 550 | ≥ 18 | ≥ 50 | ≤ 23 HRC | ≥ 55 J @ 0 °C |
Heat treatment: solution anneal 950–1050 °C → quench (air or oil) → double temper 550–620 °C. PREN ≈ 18–22. Density 7.85 g/cm³. Thermal conductivity ~25 W/m·K.
Need F6NM / S41500 to the specification above?
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