| 摘要 |
<p>A method for removing a diffusion coating which includes Al from a Ni base alloy surface portion comprises mechanically removing substantially a coating outer portion disposed on a coating diffused inner portion, and then depleting Al from the exposed diffused inner portion. Such depletion is by exposing the inner portion to a reducing gas comprising greater than about 6 wt. % halogen gas, for example a mixture of up to about 20 wt. % of a hydrohalogen gas, such as hydrogen fluoride gas, with the balance principally hydrogen gas. The temperature of exposure is at least about 1600 DEG F, preferably about 1600 DEG - 2000 DEG F for about 2 - 10 hours.</p> |
