A lever (machined from a casting made of AISI type 410 stainless steel, then surface hardened by nitriding) that was a component of the main fuel-control linkage of an aircraft engine fractured in flight after a service life of less than 50 h. Investigation (radiographic inspection) supported the conclusions that the lever broke at a cold shut extending through approximately 95% of the cross section. The normally applied load constituted an overload of the remainder of the lever. Recommendations included adding magnetic-particle inspection to the inspection procedures for this cast lever.

Liquid penetrant inspection of an ASTM A296 grade CA-15 residual heat removal pump impeller from a nuclear plant revealed a crack like indication that approximated the outer contour of the wear ring. Examination of a section containing the crack and three sections from near the main crack indication revealed that the failure was caused by hot cracking related to original weld repairs performed on the impeller casting.

An investigation was conducted to determine the cause of numerous cracks and other defects on the surface of a cast ASTM A743 grade CA-15 stainless steel main boiler feed pump impeller. The surface was examined using a stereomicroscope, and macrofractography was conducted on several cross sections removed from the impeller body. Areas that appeared to have the most severe surface damage were sectioned, fractured open, and examined using SEM. The chemistry of the impeller and an apparent repair weld were also analyzed. The examination indicated that the cracks were shrinkage voids from the original casting process. Surface repair welds had been used to fill in or cover over larger shrinkage cavities. It was recommended that more stringent visual and nondestructive examination criteria be established for the castings.