High-Temperature & Corrosion Resistant (600 / 601 / 690) – Exotic Metals LLP
These grades are primarily solid-solution strengthened
and are prized for their resistance to oxidation and various forms of aqueous
corrosion.
Inconel 600 (UNS N06600)
- The standard engineering material for applications requiring resistance to both heat
and corrosion
- Key Feature: Virtually immune to chloride-ion stress-corrosion
cracking
- Applications: Nuclear reactor components, chemical processing
(fatty acids), and furnace muffles
Inconel 601 (UNS N06601)
- A variation of 600 with added Aluminum for enhanced high-temperature oxidation
resistance
- Key Feature: Outstanding resistance to spalling (scaling) under cyclic heating up to
1250°C
- Applications: Radiant tubes, flame shields, and aerospace engine igniters
Inconel 690 (UNS N06690)
- A high-chromium variant (30% Cr) designed specifically for highly oxidizing
environments
- Key Feature: Superior resistance to nitric acid and sulfur-containing gases
- Applications: Nuclear steam generator tubes and radioactive waste vitrification
Grade
| Grade |
Ni (%) |
Cr (%) |
Fe (%) |
Tensile (MPa) |
Yield (MPa) |
| 600 |
72.0 Min |
14.0–17.0 |
6.0–10.0 |
≥ 550 |
≥ 240 |
| 601 |
58.0–63.0 |
21.0–25.0 |
Bal. |
≥ 550 |
≥ 205 |
| 690 |
58.0 Min |
27.0–31.0 |
7.0–11.0 |
≥ 585 |
≥ 240 |
High-Strength & Specialty (625 / 718 / X750)
These grades are utilized when mechanical load-bearing
capacity is as critical as corrosion resistance.
Inconel 625 (UNS N06625)
- Strengthened by Molybdenum and Niobium. It is known for its high fatigue strength
and excellent weldability
- Applications: Marine exhaust systems, flare stacks, and specialized seawater
hardware
Inconel 718 (UNS N07718)
- A precipitation-hardenable alloy that maintains high strength and ductility up to
700°C
- Key Feature: "Sluggish" hardening response allows welding without spontaneous
cracking during heating/cooling
- Applications: Gas turbine blades, rocket motors, and high-strength bolts
Inconel X750 (UNS N07750)
- Similar to 600 but made age-hardenable by adding Aluminum and Titanium
- Key Feature: Excellent properties down to cryogenic temperatures and high
creep-rupture strength
- Applications: High-temperature springs, extrusion dies, and pressure vessels
Weight Chart: Inconel Round Bar (Theoretical kg/m)
| Diameter |
625 (Density 8.44) |
718 (Density 8.19) |
X750 (Density 8.28) |
| 12 mm |
0.95 |
0.93 |
0.94 |
| 25 mm |
4.14 |
4.02 |
4.06 |
| 50 mm |
16.57 |
16.08 |
16.26 |
| 100 mm |
66.29 |
64.32 |
65.03 |
Comparison of Mechanical Strengthening
| Grade |
Strengthening Mechanism |
Hardness (Typical) |
| 600/601/625/690 |
Solid Solution / Cold Work |
80–95 HRB |
| 718 |
Precipitation Hardening |
36–44 HRC |
| X750 |
Precipitation Hardening |
30–35 HRC |
