EXPERIMENTAL STUDIES OF OPERABILITY OF HARDENED CUTTING EDGES OF PARTS

The operability of machine and tool parts is often determined by the state working surface. It on surface that cracks arise, wear corrosion processes begin. presence defects, degree depth hardening, level residual internal stresses, structure, nature transition to base material, most determine reliability service life structures. Based a critical review hardening methods, it was found one promising ones effect treated plasma jet different power density. To ensure resistance edges, with low-temperature at an indirect arc plasmatron installation. work investigated phase structural transformations after coating model samples steel 65G, studied structure built microhardness profiles. Optimal parameters processing articles are determined: distance from - 30 mm, rotation speed 10 s-1, heating time s. established optimal modes treatment were used for using example instrument (spiral drills made grades R6M5, R6AM5 11R3AM3F2) under production conditions. For all types drills, possible obtain hardened layer 1-1.5 mm deep According results metallographic analysis, microstructure contained white, non-etchable in acids zone high up 12000 MPa, which reached 0.4 mm; then there consisting martensite austenite 9000 MPa. Tests experimental resistance, carried out conditions, showed increase their resource 2 times compared did not undergo confirmed possibility multiple regrind within layer.