Metallurgical Examination of Two T23 Cast Turrets Produced by the Continental Foundry and Machine Company

摘要

Metallurgical examination of two T23 cast turrets indicates both were temper embrittled to approximately the same degree. In addition, turret No. 5 was further embrittled as a result of incomplete quench hardening, which, in conjunction with the temper embrittlement, was sufficient to cause rejection of the casting because of the displacement of fragments from the back during partial penetration of 3-in. APC M62 projectiles. Turret No. B6, despite its temper embrittlement, still possessed sufficient ductility to meet the requirement of Specification AXS-492-4. Impact tests show that turret No. B6 possess approximately twice the impact energy of Turret No. 5, both at room and reduced temperatures. Water quenching from the tempering temperature should prevent the temper embrittlement of castings of the composition and section thicknesses of the subject turrets.