Summary
Inconel 690 was developed as a higher-chromium alternative to 600 for service where 600 suffers stress-corrosion cracking, most notably steam generator tubing. The two can look alike as tube and bar.
Because chromium is the only big difference, a single XRF reading is enough. Material from nuclear plant needs its own clearance documents before it can be traded at all. See Inconel 690 scrap and nuclear industry scrap.
Side by Side
| Inconel 600 | Inconel 690 | |
|---|---|---|
| Chromium | About 15.5% | About 29% |
| Iron | About 8% | About 9% |
| Key XRF marker | Chromium near 15% | Chromium near 29% |
| Typical service | Furnace parts, caustic evaporators | Steam generator tubes, nitric acid equipment |
| Common scrap forms | Pipe, plate, sheet | Tube, tube sheet offcuts, bar |
Composition Compared
Nominal compositions compared element by element. Change either grade to compare others.
On the XRF
Switch the grade to see how the fingerprint changes. See how XRF sorts nickel alloys.
FAQ
What is the main difference between Inconel 600 and Inconel 690?
Inconel 690 has about 29% chromium against about 15.5% in Inconel 600. Iron is similar, around 8–9%, and neither carries molybdenum or niobium.
Can Inconel 600 and Inconel 690 scrap be mixed?
No. Keep them separate. A melter buying either one needs its chemistry to stay within the grade’s limits, and mixing can mean a re-sort or a different valuation.