Investigation and development of modern technologies for gradient throat plates

The topical problem of research and development of modern technological processes for production of gradient materials, in particular, gradient throat plates is considered in the paper. The goal of the work is to produce a two-layer armor plate consisting of high quality plates (HRC 62, KCU 0.5; 48-50 HRC KCU 0.9) with special physical and chemical properties. Such armor plates can resist to ballistic effect or any other impact. Two kinds of technologies developed for production of the two-layered armor plates with the above-said properties are described in the paper: production of armor plates by means of ultrahigh impulse pressure and by pack rolling. To this end, a complete technological cycle of production was developed including the steel smelting, casting and treatment under pressure and thermally. The two-layer plates were produced by means of ultrahigh pressure (explosion) in a classical way: the angle of explosion - 2.6° - 3.5^°; the explosive - ammonite (6ZHV); the charge height - 35mm; detonation velocity 4.2 km/sec. The working surfaces were treated by inductive method in order to give them hardness reaching HRC 62 and HRC 48, respectively. The other way of production of the layered plates developed recently is the pack rolling. However, the pack rolling is also connected to some difficulties. In pack rolling a special metal powder is applied between the pretreated layers for better adhesion; then, the layers are packed and after heating up to 1150 ℃ are rolled according to the preliminary defined technology of pressing. As a result, a two-layer throat plate of HRC 62 and HRC 48 is obtained. One of the significant properties of the layer production is the adhesion strength. According to the recommendation 10885-85 of the State Standards the admissible adhesion strength should be above 147mgpa - 15 kgp/mm². The adhesion strength of the layers produced by the above described technology of pack rolling was 170 mgpa (17 kgp/mm²); the adhesion strength of the layers produced by the above described technology of explosion also satisfied necessary requirements. (author)