THE PECULIARITIES OF THE FRACTURE OF HETEROPHASE INCLUSIONS OF THE TYPE "HIGH- MELTING PHASE SURROUNDED BY A LIGHT-MELTING SHELL" IN THE DEFORMATION OF STEELS

Purpose. The aim of the work was to study peculiarities crack initiation in heterophase inclusions "high-melting phase surrounded by a low-melting shell" type during deformation steels. Methods. destruction various types investigated specimens from steels 08T, 08Yu, 12GS, 08kp, 09G2S, NB-57, 08GSYuTF temperature range 20...1 200 °C [1; 5]. Samples were subjected tension, compression and bending vacuum at temperatures 20…1 on Instron-1195 IMASH-5C with special grippers, movement speed which 20 mm / min. Methods investigation –petrography optical microscopy (Neophot-21) used. Results. It found that process different regimes, microcracks originating near can be brittle ductile. In this case, role level plasticity phases making up inclusion, depends temperature, is important. features microcrack are shown for combinations plastic non-deformable inclusions. interaction steel matrix analyzed. has been established nucleation growth within occurs both along internal interphase boundaries. Scientific novelty. Specific associated " high-melting type, have combination steels, established. critical degrees samples, upon reaching noticeable appeared boundaries, depend nature Practical significance. use results obtained will make it possible develop technologies producing regulated nonmetallic inclusions, significantly increase their technological operational characteristics, as well prevent formation kinds defects processing pressure operation products.