Metallurgical Examination of Twelve 1/2 Inch Rolled Armor Plates Manufactured by Republic Steel Corporation

摘要

Metallurgical examination, including Brinell hardness surveys, fracture tests for steel soundness and fibre, macro-etch tests, and microscopic examination, was conducted on each of the twelve armor plates furnished by Republic Steel Corp. Chemical analyses were taken of two plates. All plates were satisfactorily heat treated as revealed by the fibre test. However, a trace of crystallinity was evident in the two plates with a hardness of over 360. Plate 4-1, although completely fibrous, exhibited an appreciable amount of ferrite which indicated faulty heat treatment. The improper fibre test indication was undoubtedly because of the abnormally low hardness of this plate.