Rapid Ultrasonic Inspection of Artillery Projectiles. Revision
Abstract
Results of a 3-month study to evaluate metallurgical and acoustic properties of HF-1 steel are presented. The objectives were to determine the cause of and solution for reduced ultrasonic signal generation efficiencies evident during ultrasonic inspection of M549 (RAP) artillery projectiles with electromagnetic acoustic transducers(EMATs). It was shown that reduced generation efficiencies were the result of an in-process heat-treatment during fabrication and that the phenomenon was limited to the first approximately 0.007 in. (0.178 mm) of surface material. Accordingly, surface material was examined prior to and following heat-treatment to determine the metallurgical and/or morphological changes that cause this impedence. A hypothesis is that reduced ultrasonic signal efficiencies are possibly the result of a weakly magnetic continuous grain boundary phase of Fe3C. Some results are contradictory, however, and as such, studies should be continued to further evaluate this hypothesis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA078916
Entities
People
- Joseph H. Mulherin
- Murray W. Mahoney