Warm Working of Armor for Improved Toughness

The transition temperature of Mn-Mo armor steels, quenched and tempered in either the temper embrittling or tempered martensite embrittling range, can be significantly lowered by warm working. The improved toughness, however, is developed only when the direction of prestraining and testing is identical. Deformation in one direction followed by testing in the opposite direction produced an increased transition temperature.