Chief Metallurgist, The American Brake Shoe and Foundry Co., Mahwah, N. J.
Pages: 16 Published: Jan 1943
The cooperation of five X-ray laboratories has made possible the collection of interesting and instructive data concerning the utilization of radiographic examination for metallurgical control and inspection over a wide range of castings. The relative definition of ordinary defects upon the films varies with the general laboratory technique, the type and location of the defect with respect to the direction of the beam and especially with the thickness of the sections. The more familiar imperfections readily interpreted from the films are shrink-age cavities, flocculent shrink, blowholes from mold or metal gases, cracks, inclusions, and pronounced dendritic formations. Arbitrary specifications frequently impose hardships upon the foundry and unnecessarily increase the ultimate cost to the consumer. Maintenance of adequate standards without expensive destructive testing is an outstanding advantage of radiographic inspection. In the laboratories of the Aluminum Company of America, radiography has been used primarily in the development of satisfactory casting or fabricating technique and to a comparatively small extent for the routine inspection of commercial products. The Electro-Alloys Co. and the American Manganese Steel Co. have utilized X-ray examination for similar purposes. The unit at Rock Island Arsenal has been used strictly as an inspection tool. Manufacturers submit sample castings which are radiographed throughout. Complete reports are forwarded to the producer for his information and guidance. The Watertown Arsenal has combined both production and inspection routine as the problems arise. The employment of small-scale pilot castings (175:1 by weight) for the study of homogeneity control and the attainment of directional solidification in production is described in detail.
Paper ID: STP43904S