Difference Between Inconel and Stainless Steel

Inconel

Inconel is a family of austenitic nickel-chromium-based superalloys while Stainless steel is an alloy of Iron with a minimum of 10.5% Chromium. Chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'.

Inconel Composition

Inconel Element (% by mass) Ni Cr Fe Mo Nb Co Mn Cu Al Ti Si C S P B 600 72.0 14.0–17.0 6.0–10.0 1.0 0.5 0.5 0.15 0.015 617 44.2–56.0 20.0–24.0 3.0 8.0–10.0 10.0–15.0 0.5 0.5 0.8–1.5 0.6 0.5 0.15 0.015 0.015 0.006 625 58.0 20.0–23.0 5.0 8.0–10.0 3.15–4.15 1.0 0.5 0.4 0.4 0.5 0.1 0.015 0.015 690 59.5 30 9.2 0.35 0.01 0.02 0.35 0.019 0.003 718 50.0–55.0 17.0–21.0 balance 2.8–3.3 4.75–5.5 1.0 0.35 0.2–0.8 0.65–1.15 0.3 0.35 0.08 0.015 0.015 0.006 X-750 70.0 14.0–17.0 5.0–9.0 0.7–1.2 1.0 1.0 0.5 0.4–1.0 2.25–2.75 0.5 0.08 0.01

Inconel alloys

Alloys of inconel include:

• Inconel 600: Solid solution strengthened
• Inconel 601
• Inconel 625: Acid resistant, good weldability. The LCF version is typically used in bellows.
• Inconel 690: Low cobalt content for nuclear applications, and low resistivity
• Inconel 713C: Precipitation hardenable nickel-chromium base cast alloy
• Inconel 718: Gamma double prime strengthened with good weldability
• Inconel 751: Increased aluminium content for improved rupture strength in the 1600 °F range
• Inconel 792: Increased aluminium content for improved high temperature corrosion properties, used especially in gas turbines
• Inconel 939: Gamma prime strengthened to increase weldability

Inconel Equivalent Grades

STANDARD WERKSTOFF NR. UNS GOST AFNOR JIS BS EN OR Inconel 600 2.4816 N06600 МНЖМц 28-2,5-1,5 NC15FE11M NCF 600 NA 13 NiCr15Fe ЭИ868 Inconel 601 2.4851 N06601 XH60BT NC23FeA NCF 601 NA 49 NiCr23Fe ЭИ868 Inconel 617 2.4663 N06617             Inconel 625 2.4856 N06625 ХН75МБТЮ NC22DNB4M NCF 625 NA 21 NiCr22Mo9Nb ЭИ602 Inconel 690 2.4642 N06690             Inconel 718 2.4668 N07718             Inconel 725 - N07725             Inconel X-750 2.4669 N07750            

Inconel Melting Point, Density and Tensile Strength

  Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation 600 8.47 g/cm3 1413 °C (2580 °F) Psi – 95,000 , MPa – 655 Psi – 45,000 , MPa – 310 40 % 601 8.1 g/cm3 1411 °C (2571 °F) Psi – 80,000 , MPa – 550 Psi – 30,000 , MPa – 205 30 % 617 8.3g/cm³ 1363°C ≥ 485 MPa ≥ 275 MPa 25 % 625 8.4 g/cm3 1350 °C (2460 °F) Psi – 135,000 , MPa – 930 Psi – 75,000 , MPa – 517 42.5 % 690 8.3g/cm³ 1363°C ≥ 485 MPa ≥ 275 MPa 25 % 718 8.2 g/cm3 1350 °C (2460 °F) Psi – 135,000 , MPa – 930 Psi – 70,000 , MPa – 482 45 % 725 8.31 g/cm3 1271°C-1343 °C 1137 MPa 827 MPa 20 % X-750 8.28 g/cm3 1430°C 1267 MPa 868 MPa 25 %

Stainless Steel

Stainless Steel Equivalent Grades

STANDARD WERKSTOFF NR. UNS JIS BS GOST AFNOR EN SS 304 1.4301 S30400 SUS 304 304S31 08Х18Н10 Z7CN18‐09 X5CrNi18-10 SS 304L 1.4306/1.4307 S30403 SUS 304L 304S11 03Х18Н11 Z3CN18‐10 X2CrNi18-9 / X2CrNi19-11 SS 310 1.4845 S31000 - - - - - SS 310S 1.4845 S31008 SUS310S - 20Ch23N18 - X8CrNi25-21 SS 316 1.4401 / 1.4436 S31600 SUS 316 316S31 / 316S33 - Z7CND17‐11‐02 X5CrNiMo17-12-2 / X3CrNiMo17-13-3 SS 316L 1.4404 / 1.4435 S31603 SUS 316L 316S11 / 316S13 03Ch17N14M3 / 03Ch17N14M2 Z3CND17‐11‐02 / Z3CND18‐14‐032 X2CrNiMo17-12-2 / X2CrNiMo18-14-3 SS 317 1.4449 S31700 SUS 317 - - - X6CrNiMo19-13-4 SS 317L 1.4438 S31703 SUS 317L - - - X2CrNiMo18154 SS 321 1.4541 S32100 SUS 321 - 08Ch18N10T - X6CrNiTi18-10 SS 321H 1.4541 S32109 SUS 321H - - - X6CrNiTi18-10 SS 347 1.4550 S34700 SUS 347 - 08Ch18N12B - X6CrNiNb18-10 SS 347H 1.4961 S34709 SUS 347H - - - X7CrNiNb18-10 SS 446 1.4762 S44600 - - - - -

Stainless Steel Composition

Grade C Mn Si P S Cr Mo Ni N SS 304 0.08 max 2 max 0.75 max 0.040 max 0.030 max 18 – 20 - 8 – 11 - SS 304L 0.03 max 2 max 0.75 max 0.045 max 0.030 max 18 – 20 - 8 – 12 0.10 max SS 310 0.25 max 2 max 1.50 max 0.045 max 0.030 max 24 - 26 - 19 - 22 - SS 310S 0.08 max 2 max 1.50 max 0.045 max 0.030 max 24 - 26 - 19 - 22 - SS 316 0.08 max 2 max 0.75 max 0.045 max 0.030 max 16 - 18 2 - 3 10 - 14 0.1 max SS 316L 0.3 max 2 max 0.75 max 0.045 max 0.030 max 16 - 18 2 - 3 10 - 14 0.10 max SS 317 008 max 2 max 1 max 0.040 max 0.03 max 18 - 20 3 - 4 11 - 14 0.10 max SS 317L 0.035 max 2 max 1 max 0.040 max 0.03 max 18 - 20 3 - 4 11 - 15 - SS 321 0.08 max 2 max 0.75 max 0.045 max 0.03 max 17 - 19 5xC min
0.60% max 9 - 12 0.10 max SS 321H 0.04 - 0.10 max 2 max 0.75 max 0.045 max 0.03 max 17 - 19 4xC min
0.60% max 9 - 12 0.10 max SS 347 0.08 max 2 max 0.75 max 0.045 max 0.03 max 17 - 20 10xC min
1.00 max 9 - 13 62.74 SS 347H 0.04 – 0.10 2 max 0.75 max 0.045 max 0.03 max 17 - 20 8xC min
1.00 max 9 - 13 62.74 SS 446 0.2 max 1.5 max 0.75 max 0.040 max 0.03 max 23 – 30 0.10 – 0.25 0.50 max Balance

Stainless Steel Melting Point, Density and Tensile Strength

Grade Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation SS 304 8.0 g/cm3 1400 °C (2550 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 304L 8.0 g/cm3 1400 °C (2550 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 40 % SS 310 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 310S 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 316 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 316L 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 40 % SS 317 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 317L 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 321 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 321H 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 35 % SS 347 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 40 % SS 347H 8.0 g/cm3 1454 °C (2650 °F) Psi – 75000 , MPa – 515 Psi – 30000 , MPa – 205 40 % SS 446 7.5 g/cm3 1510 °C (2750 °F) Psi – 75,000 , MPa – 485 Psi – 40,000 , MPa – 275 20 %