Effect of Preferred Orientation and Related Metallurgical Parameters on Mechanical Properties and Ballistic Performance of High-Hardness Steel Armor.

摘要

Optimum ballistic properties were obtained in a medium-carbon 5Ni-Si-Mo-Cu armor steel by rolling at temperatures (approximately 1500F) just above the critical range followed by quenching and tempering. Although the mechanical properties of the armor plate were slightly increased by this thermomechanical treatment,these increases were not sufficient to explain the improved ballistic performance. Rather,the improvement also resulted from a simultaneous beneficial change in a number of metallurgical parameters. These included a finer martensite plate size and an increase in the amount of retained austenite both of which have a beneficial effect on toughness. Because of the low rate of austenite decomposition in this steel,no ferrite formed during intercritical rolling. Thus,thermomechanical treatment performed at temperatures within the critical range was essentially the same as that performed at temperatures just above the critical range. (Modified author abstract)