Metallurgical Examination of Sections from 3-5 in. Thick Face Hardened Armor

摘要

Samples from 3, 4, and 5-in. thick face hardened plates, which were used for projectile testing, were examined metallurgically. Heat treatment was excellent and steel soundness characteristics were satisfactory on all samples except one from the 4-in. plate. Insufficient data was obtained upon which to recommend a testing procedure for controlling the uniformity of such plates employed for projectile testing. However, a fracture test will indicate plate unsoundness, if present, whether or not heat treatment was satisfactory, and will yield a satisfactory indication of case depth.