Analysis of the status of precipitates in heat resistant alloys

In the analysis of the status of alloys, the kind, composition and amount of precipitation of all the precipitates in those materials must be always grasped. This study aimed at the development of techniques to grasp the change of precipitates as universal as possible, and the following points were clarified. In the extraction of precipitates, the amount of precipitation was regarded as important heretofore, there fore, the process with much loss was apt to be neglected, but it is more important to confirm all kinds of precipitates. It was clarified that MoC was present in Inconel 617 as a main precipitate. As the method of identifying precipitates, it was shown that the isolation by some suitable method is effective as well as X-ray diffraction and electron beam diffraction as the state of mixture. X-ray fluorometry was applied to the quantitative analysis of precipitates of very small amount. As for large precipitates, the analysis by EPMA without extraction was also effective. The high accuracy was obtained by correction calculation. The image analysis of structure photographs and EPMA without extraction were examined to avoid the extraction loss, and these were found to be usable. (Kako, I.)