Cadmium LHE for aerospace
LHE stands for low hydrogen embrittlement. On a structural aerospace component, hydrogen embrittlement gives no second chance.
The electrolytic process generates ionic hydrogen that diffuses into the steel and causes internal stress. In a high-strength part, that becomes a crack. LHE cadmium is formulated to minimize that absorption, and relief in a calibrated oven removes what is left.
The AMS-QQ-P-416 requirement is 96 hours without white corrosion. Our ASTM B117 report, from an ISO/IEC 17025 accredited laboratory, records 1,000 hours without red rust, and a seven-system test kept the cadmium intact at 3,395 hours.
Relief is done immediately after plating, between 150 °C and 250 °C, in ovens with a temperature uniformity survey (TUS) and traceable thermocouple calibration to API Specification 6A and ISO 10423.
Technical data
- Standard
- AMS-QQ-P-416 · aerospace
- Standard requirement
- 96 h without white corrosion
- ASTM B117 report
- 1,000 h without red rust · ISO/IEC 17025 accredited
- 7-system test
- intact at 3,395 h
- Hydrogen relief
- 150 °C to 250 °C · oven with TUS
- Industries
- Aerospace · defense · nuclear · offshore
What each standard sets for Cadmium LHE for aerospace.
| Standard | What it covers | What it sets here |
|---|---|---|
| AMS-QQ-P-416 | Aerospace specification | The AEROSPACE-sector standard for electrodeposited cadmium — not an oil and gas one. It governs the low-embrittlement (LHE) variant. |
| API Specification 6A | Oven calibration | Temperature uniformity of the oven used for hydrogen relief. |
| ISO 10423 · Annex M | Temperature uniformity | Defines the survey (TUS) that proves the temperature across the whole load, not only at the control point. |
| ASTM B766 | Coating specification | The oil and gas cadmium designation, class 12 type II. It appears here as a comparison reference: in aerospace, AMS governs. |
What specifiers usually ask.
What does LHE mean in cadmium?
Low Hydrogen Embrittlement. It is the process variant formulated to generate less hydrogen during deposition, used on high-strength steel in aerospace parts, where brittle fracture is not an acceptable hypothesis.
Why is the standard here AMS-QQ-P-416 and not ASTM B766?
Because they are different industries. AMS-QQ-P-416 is the aerospace standard; in oil and gas the designation is ASTM B766 class 12 type II. Swapping one for the other on a drawing is a specification error, not a synonym.
How is hydrogen relief proven?
By the oven temperature uniformity survey (TUS) and the traceable thermocouple calibration, to API Specification 6A and ISO 10423. It is the record that shows the whole load reached the range between 150 °C and 250 °C, and not just the control thermocouple point.