Tube stainless steel Sanmac® 4435

aeronautical

Sanmac® 4435 is a molybdenum-alloyed austenitic chromium-nickel stainless steel with improved machinability and a guaranteed minimum molybdenum content of 2.5%. It is supplied primarily as hollow bar and intended for applications requiring better corrosion resistance than standard 304/304L steels.

Applications

• Machine parts for tube and pipe fittings
• Components for valves, pumps, heat exchangers and vessels
• Tubular shafts in chemical, petrochemical, fertilizer, pulp and paper and power industries, and components for pharmaceuticals, food and beverage production

Corrosion resistance

• Good resistance to organic acids at high concentrations and temperatures (except formic acid and acids with corrosive contaminants)
• Resistance to inorganic acids such as phosphoric acid at moderate concentrations/temperatures; sulfuric acid below 20% at moderate temperatures and in some high-concentration, low-temperature sulfuric environments
• Resistance to sulfates, sulfides and sulfites and to caustic environments
• Low carbon content gives improved resistance to intergranular corrosion compared with typical ASTM 316 steels
• Pitting and crevice corrosion resistance is improved by the ~2.6% Mo content compared with AISI 304 and ordinary ASTM 316/316L with ~2.1% Mo
• Susceptible to stress corrosion cracking like other austenitic steels (risk increases above ~60°C in chloride-containing environments); for higher resistance consider duplex/ferritic alternatives such as SAF™ 2304, Alleima® 10RE51 or SAF™ 2205
• Usable in air up to 850°C and steam up to 750°C; service in flue gases containing sulfur is possible up to ~600–750°C depending on conditions (oxidizing vs reducing atmosphere and presence of impurities)

Forms of supply

• Hollow bar: stocked up to 250 mm OD in solution-annealed and white-pickled condition (catalogue references S-110-ENG, S-029-ENG or S-02909-ENG)
• Other forms: also available in round bar and billet
• Hollow bar dimensional tolerances: OD +2 / -0% (minimum +1 / -0 mm); ID +0 / -2% (minimum +0 / -1 mm); straightness ±1.5 mm/m; guaranteed component sizes after machining for OD < 2.5 × OD

Welding

• Good weldability. Suitable methods: MMA/SMAW and gas-shielded arc welding; TIG/GTAW is first choice
• Because of alloying for machinability, welded beads may show more surface oxides and possible arc instability in TIG/GTAW without filler; welding with filler behaves like standard 316L
• Recommended heat input < 2.0 kJ/mm and interpass temperature < 150°C. Preheating and PWHT normally not necessary
• Recommended filler metals: TIG/GTAW or MIG/GMAW: ISO 14343 S 19 12 3 L / AWS A5.9 ER316L (e.g. Exaton 19.12.3.L); MMA/SMAW: ISO 3581 E 19 12 3 L R / AWS A5.4 E316L-17 (e.g. Exaton 19.12.3.LR)

Machining

• Sanmac® is Alleima's trademark for improved machinability concept: improved non-metallic inclusions, optimized chemical composition and process parameters deliver better machinability without jeopardising corrosion resistance and mechanical strength
• Detailed cutting-data recommendations (turning, threading, parting/grooving, drilling, milling, sawing) are provided in brochure S-02909-ENG; cutting speed/feed ranges depend on desired tool life and cut length

Caractéristiques / spécifications techniques

• Standards: ASTM: MT 316L, MT 316; UNS: S31603, S31600; EN number: 1.4435, 1.4436; EN name: X2CrNiMo18-14-3, X3CrNiMo17-13-3; JIS: SUS316TKA
• Product standards: EN 10216-5*, EN 10297-2, ASTM A511, JIS G3446 (* leakage test deferred to finished component)
• Approval: JIS Approval No. SE9402 for Stainless Steel Tubes
• Chemical composition (nominal), wt%: C ≤ 0.030; Si 0.2; Mn 1.8; P ≤ 0.040; S ≤ 0.017; Cr 17.5; Ni 12.5; Mo 2.6
• Mechanical properties at 20°C (metric): Proof strength Rp0.2 ≥ 220 MPa; Rp1.0 ≥ 250 MPa; Tensile strength 515–690 MPa; Elongation A ≥ 45%; A2 ≥ 35%; Hardness HRB ≤ 90
• Mechanical properties at 20°C (imperial): Proof strength Rp0.2 ≥ 32 ksi; Rp1.0 ≥ 36 ksi; Tensile strength 75–100 ksi; Elongation A ≥ 45%; A2 ≥ 35%; Hardness HRB ≤ 90
• Impact strength: Very good at room and cryogenic temperatures; meets EN 13445-2 (min. 60 J at -270°C) and EN 10216-5 (min. 60 J at -196°C)
• Proof strength — high temperature (metric, MPa minima): 50°C: Rp0.2 200 / Rp1.0 230; 100°C: 180 / 215; 150°C: 165 / 195; 200°C: 150 / 180; 250°C: 140 / 170; 300°C: 135 / 160; 350°C: 130 / 155; 400°C: 125 / 150; 450°C: 120 / 145; 500°C: 120 / 145; 550°C: 115 / 140; 600°C: 110 / 135
• Density: 8.0 g/cm³ (0.29 lb/in³)
• Thermal conductivity (W/m·°C): 20°C: 14; 100°C: 15; 200°C: 17; 300°C: 18; 400°C: 20; 500°C: 21; 600°C: 23
• Specific heat capacity (J/kg·°C): 20°C: 485; 100°C: 500; 200°C: 515; 300°C: 525; 400°C: 540; 500°C: 555; 600°C: 575
• Thermal expansion, mean values (×10⁻⁶ per °C): 30–100°C: 16.5; 30–200°C: 17; 30–300°C: 17.5; 30–400°C: 18; 30–500°C: 18; 30–600°C: 18.5; 30–700°C: 18.5
• Modulus of elasticity (metric): 20°C: 200 GPa; 100°C: 194 GPa; 200°C: 186 GPa; 300°C: 179 GPa; 400°C: 172 GPa; 500°C: 165 GPa
• Hollow bar tolerances / supply: Stocked in many sizes up to 250 mm OD, solution-annealed and white-pickled; OD tolerance +2 / -0% (min +1/-0 mm), ID +0 / -2% (min +0/-1 mm), straightness ±1.5 mm/m. Hollow bar delivered heat treated.