Tube stainless steel Sanmac® 4571

aeronautical

Sanmac® 4571 (1.4571 / 316Ti) is a titanium-stabilized, molybdenum-alloyed austenitic chromium-nickel steel with improved machinability, intended for billets used in demanding industrial applications.

Standards

• ASTM: 316Ti
• UNS: S31635
• EN Number: 1.4571
• W.Nr.: 1.4571
• DIN: X 6 CrNiMoTi 17 12 2

Product standards & certificates

• Product standards: EN 10088-3, ASTM A-314
• Suitable for production of flanges etc. according to AD-2000-W2
• Certificates: Status according to EN 10 204/3.1

Chemical composition (nominal) %

• C: 0.03
• Si: 0.4
• Mn: 1.8
• P: ≤0.045
• S: ≤0.030
• Cr: 17
• Ni: 11
• Mo: 2.1
• Others: Ti > 5 × (C + N)

Applications (industrial categories → typical applications)

• Chemical industry → Flanges
• Food industry → Valves
• Petrochemical industry → Fittings
• Pulp and paper industry → Couplings
• Nuclear industry → Rings
• Other typical applications → Seals, Bolts and nuts, Shafts, Forgings, Discs

Corrosion resistance

• Good resistance to organic acids at high concentrations and temperatures.
• Good resistance to inorganic acids (e.g. phosphoric and sulphuric) at moderate concentrations and temperatures; can be used in sulphuric acid >90% at low temperature.
• Resistant in salt solutions (sulphates, sulphides, sulphites) and caustic environments.
• Improved resistance to intergranular corrosion versus unstabilized steels due to titanium stabilisation (prevents chromium carbide precipitation in 450–850°C range).
• Improved pitting/crevice resistance due to ~2.1% Mo compared with AISI 304/304L.
• Austenitic steels can be susceptible to stress corrosion cracking above ≈60°C in tensile stress and chloride-containing environments; avoid such service conditions if possible.
• Gas corrosion: usable in air up to 850°C and in steam up to 750°C (creep behavior and flue-gas impurities must be considered).

Forms of supply — sizes, tolerances and surface conditions

• Produced as round-cornered square and round billets in a wide range of sizes; larger sizes on request.
• Square billets: unground, spot ground or fully ground.
• Round billets: peel turned or black condition.
• Selected size / tolerance examples (rolled/forged condition): Square billets sizes 80 mm (±2) length 4–6.3 m; 100–150 mm (±3) length 4–6.3 m; 160–200 mm (±4) length 4–6.3 m; >200–350 mm (±5) length 3–5.3 m.
• Peel turned round billets: 75–200 mm (±1) length max 10 m; >200–450 mm (±3) length 3–8 m.
• Unground round billets: examples cover 77–112 mm (±2) up to max length 10 m and other listed diameters with ±2 tolerance.

Heat treatment

• Billets are delivered hot worked and not solution annealed.
• Recommended solution annealing after processing: 1060–1070°C (1940–1960°F) with rapid cooling in air or water.

Mechanical properties (solution annealed and quenched condition)

• At 20°C (68°F): Proof strength Rp0.2 ≥ 210 MPa; Rp1.0 ≥ 245 MPa; Tensile strength Rm 515–700 MPa; Elongation A ≥ 40%; Reduction of area Z ≥ 50%; Brinell hardness HB ≤ 215.
• Impact strength: very good at room and cryogenic temperatures; meets 60 J at -196°C per EN13445-2 (UFPV-2) and EN 10272.
• High-temperature proof/tensile strength values provided up to 500°C (see datasheet tables for detailed values).

Physical & thermal properties

• Density: 8.0 g/cm3 (0.29 lb/in3).
• Thermal conductivity (W/m·°C): e.g. 20°C → 14; 100°C → 15; up to 600°C → 23 (see table for full values).
• Specific heat capacity (J/kg·°C): e.g. 20°C → 485; 100°C → 500; up to 600°C → 575.
• Mean thermal expansion (×10-6 per °C) in ranges: 30–100°C → 16.5; 30–300°C → 17.5; up to 30–700°C → 19 (see table for full ranges).
• Modulus of elasticity: 20°C → 200 GPa (≈29.0 ksi); decreases with temperature (tables provided).

Hot working & welding

• Recommended hot working: 1220–1260°C (2230–2300°F); do not go below 900°C (1650°F). Rapid cooling in water or air after hot working.
• Weldability: good. Preferred fusion methods TIG/GTAW (first choice) and gas-shielded arc welding; MMA/SMAW also suitable.
• Because of alloys added for machinability, surface oxides on weld beads may be higher than standard 1.4571/316Ti; welding with filler material gives similar behavior to standard 1.4571/316Ti.
• Recommended heat input < 1.5 kJ/mm and interpass < 100°C; preheat/post-weld heat treatment normally not necessary.
• Recommended filler metals (examples): ISO 14343 S 19 12 3 Nb / AWS A5.9 ER318 (e.g. Exaton 19.12.3.Nb), ISO 14343 S 19 12 3 L / AWS A5.9 ER316L (e.g. Exaton 19.12.3.L), and corresponding MMA electrodes ISO 3581 E 19 12 3 variants.

Machining (improved machinability)

• Sanmac® materials have improved machinability without compromising corrosion resistance and mechanical strength via optimized non-metallic inclusions, chemical composition and production parameters.
• Detailed cutting data provided for turning, drilling, milling, tapping, threading and sawing; example turning starting values: finishing inserts MF/GC2015 feed 0.15 mm/rev at 240 m/min; medium machining MM/GC2025 feed 0.25 mm/rev at 210 m/min.
• Drilling, milling and threading charts and recommended tooling grades are provided in the datasheet (see machining chart figure).

Additional products

• Available in related product forms: Seamless tube and pipe (Sanmac®), Hollow bar (Sanmac®).

caractéristiques / spécifications techniques

• Commercial name / Model: Sanmac® 4571
• Brand: Sanmac®
• EN no.: 1.4571 • UNS: S31635 • ASTM: 316Ti • W.Nr.: 1.4571
• Chemical composition (nominal): C 0.03; Si 0.4; Mn 1.8; P ≤0.045; S ≤0.030; Cr 17; Ni 11; Mo 2.1; Ti > 5×(C+N)
• Density: 8.0 g/cm³
• Proof strength (20°C): Rp0.2 ≥210 MPa; Rp1.0 ≥245 MPa
• Tensile strength (20°C): 515–700 MPa; Elongation ≥40%
• Hardness (HB): ≤215
• Service temperature (gas): air up to 850°C; steam up to 750°C (consider creep and environment)
• Typical supply forms: round-cornered square and round billets; surface conditions: unground/spot/fully ground (square) and peel-turned/black (round)