Accession Number : ADA306036

Title :   Improved Rolled Homogeneous Armor (IRHA).

Descriptive Note : Final rept. Jan-Dec 94,

Corporate Author : DYNAMIC SCIENCE INC ABERDEEN MD

Personal Author(s) : Leavy, R. B.

PDF Url : ADA306036

Report Date : MAR 1996

Pagination or Media Count : 39

Abstract : This report describes tests conducted on an enhanced conventional armor steel. The improved rolled homogeneous armor (IRHA) steel was designed to be harder than conventional rolled homogeneous armor (RHA), but maintain the same weight and weldability as RHA. This was accomplished through optimizing the alloy chemistry and heat treatment of the IRHA. The material was tested against a penetrator with a length-to diameter aspect ratio of 5 tungsten alloy slug fired from a 105-mm bore diameter gun. Standard RHA, high-hard, and some experimental harder steels were also tested for comparison with the IRHA results. The ballistic data of the materials tested was compared to semiempirical calculations of the performance based on target hardness. Two separate types of IRHA were examined. The heat treatment and tempering temperatures produced two different IRHA hardnesses. A temper of 985 or 42 deg F resulted in an armor haniness of Rockwell C Scale 41 (Rc 41) or the balder Rc 47, respectively. Standard RHA has a hardness in the Rc 27-34 range, with the RHA used in this program being Rc 34. Tests performed utilized semi-infinite as well as finite laminate block targets. Penetration and breckout effects were analyzed to determine the overall ballistic efficiency of the IRHA.

Descriptors :   *VEHICULAR ARMOR, *HOMOGENEITY, *ROLLING(METALLURGY), EFFICIENCY, ALLOYS, TARGETS, STEEL, HEAT TREATMENT, COSTS, CODING, CHEMISTRY, KINETIC ENERGY PROJECTILES, BALLISTICS, HARDNESS, TEMPERING, ASPECT RATIO, WELDABILITY, ORDNANCE STEEL.

Subject Categories : Fabrication Metallurgy
      Armor

Distribution Statement : APPROVED FOR PUBLIC RELEASE