Ballistic Testing of SSAB Ultra-High-Hardness Steel for Armor Applications

• Main Authors: Showalter, Dwight D, Gooch, William A, Burkins, Matthew S, Koch, R S
• Format: Report
• Language: English
• Subjects: Ammunition and Explosives; Armor; ARMOR APPLICATIONS; ARMOR PIERCING AMMUNITION; ARMOR PLATE; BALLISTIC TESTING; BALLISTICS; DUAL HARDNESS; MILITARY REQUIREMENTS; PROJECTILES; ROLL BONDING; SMALL ARMS AMMUNITION; SPECIFICATIONS; SSAB(SWEDISH STEEL OXELSUND AB); STEEL; TEST AND EVALUATION; ULTRA HIGH HARDNESS STEEL; WEIGHT

The highest-performing U.S. steel alloys for armor-piercing (AP) bullet protection are manufactured to MIL-DTL-46100E, high-hardness armor (HHA) with a hardness range of 477 534 Brinell hardness number (BHN), and to MIL-A-46099C, dual hardness armor (DHA), which is produced by roll bonding a 601 712 BHN front plate to a 461 534 BHN back plate. While these materials still serve their intended applications, monolithic ultra-high-hardness (UHH) steels with a hardness of 600 BHN or greater have been developed. This class of steels increases AP bullet defeat, reduces armor weight, and eliminates the manufacturing difficulties inherent in DHA. Swedish Steel Oxel sund AB (SSAB) produces a number of grades of steel, which have previously been assessed against AP ammunition. However, SSAB has two UHH armor steels designated ARMOX 600T and ARMOX ADVANCE that meet this hardness criteria. ARMOX 600T is a nominal 600 BHN steel while ARMOX ADVANCE has a nominal hardness of Rockwell C58-63 (650 BHN). This report assesses the performance of these steels against two projectiles that will be used to generate a new military specification for UHH steel armor. The performance of these UHH steels will be compared to the current HHA MIL-DTL-46100E specification. Prepared in collaboration with SSAB Oxelosund AB, Sweden.