穿甲侵彻过程中靶板内绝热剪切带特性及形成原因分析

Analysis on Adabiatic Shear Band Characteristic and Cause of Formation in Process of Penetration in Armor

发射小口径脱壳穿甲弹 ,对 30CrMnMo钢装甲靶板产生的绝热剪切带特性及形成原因进行了分析。结果表明 :在开坑和冲塞阶段 ,不产生绝热剪切带 ;在稳定的侵彻阶段 ,可达到绝热剪切带需要的应变量 ,从而产生绝热剪切带 ,并呈稀疏状分布 ,与侵彻方向大约成 4 5°夹角。在本试验条件下 ,产生绝热剪切带的临界剪应变大约为 0 .4 7,临界温度大约为 391℃ .产生绝热剪切带后 ,在剪切带内变形增大且不均匀 ,将产生应力应变集中 ,和周围材料变形不协调 ,在随后的冷却过程中易产生裂纹。

Characteristics and causes of formation of adiabatic shear bands in 30CrMnMo armor steel plate are analyzed. It is shown that the adiabatic shear bands don't occur in the initial stage of launching and plugging. They occur in the stable penetrating stage because of enough strain. The adiabatic shear bands distributing sparsely make an angle of about 45° with penetrating direction. The critical shearing strain forming the adiabatic shear bands is about 0.47 and the critical temperature is about 391℃ . Non-homogenous deformation and centralizing of stress and strain in the adiabatic shear bands will cause micro-crack and micro-pores during cooling of the plate.