Inconel Reagent
Inconel Etchant
Material Specific
Composition
Hydrogen peroxide 10–20%, Hydrogen chloride 20–40%, Nitric acid 10–30%
PACE product, by weight
Method
Swab
Time
10–30 s
Alternative Names
Tags
Reveals
Grain boundaries, primary carbides (MC, M23C6), large gamma-prime in aged Ni-base superalloys
Typical Results
Modified aqua regia with hydrogen peroxide added for additional oxidation power. Specifically designed for hard-to-etch nickel-base superalloys such as Inconel 600/625/718/738, Hastelloy C-276, and Waspaloy. The H2O2 enhances attack on the Cr-rich passive layer that protects superalloy grain boundaries.
Application Method
Method:Swab
Typical Time:10–30 s
Preparation Notes
PACE Inconel Etchant is supplied ready-to-use. Composition (by weight):
| Ingredient | CAS No. | % | Hazardous |
|---|---|---|---|
| Hydrogen peroxide | 7722-84-1 | 10–20% | Yes |
| Hydrogen chloride | 7647-01-0 | 20–40% | Yes |
| Nitric acid | 7697-37-2 | 10–30% | Yes |
| Water | 7732-18-5 | 10–50% | No |
Application Notes
Swab 10–30 s at room temperature. Visible bubbling on contact is normal (peroxide reaction). Rinse with water then ethanol.
Troubleshooting
No bubbling on contact means the H2O2 has decomposed; discard. Solution-treated condition etches faster than aged. Aged 718 / Waspaloy may need the longer end of the time window.
Storage Notes
Amber glass, cool storage (refrigerate if possible). Per PACE SDS, H2O2 decomposes over months; replace when reactivity drops.
Alternative Etchants
- Glyceregia
- Marble's Reagent
- ASTM No. 157
Similar Etchants
- Glyceregia