Metallurgical Examination of Two 1/4 in. Rolled Homogeneous Armor Plates which Exhibited Differences in Steel Soundness under Ballistic Tests
WATERTOWN ARSENAL LABS MA WATERTOWN ARSENAL United States
Pagination or Media Count:
In this report two 14 in. plates were examined one of which exhibited back spalls when subjected to impacts with cal. .30 AP M2 projectiles at a velocity such that the jacket went through the plate the other plate exhibited a clean punching condition under the same circumstances. It was found that a centerline plane of weakness caused by a concentration of silicate type stringers was responsible forthe back spalls. This plane of weakness was not revealed by the fracture test for steel soundness yet its presence was disclosed by the fracture test for steel soundness yet its presence was disclosed by the macroetch test and a special torsion test.