Scientific adviser professor, Alimov V.I.
The purpose of the given work is studying tool manufacture in Joint-Stock Company " Lugansk factory of cranked shaft ", comparison of influence of various methods of manufacture and a degree of deformation tool steel on their structure and properties.
 In Joint-Stock Company "Lugansk factory of cranked shaft " with various types of the tool are used. Such as: drills of various diameter, reamer bit, a vertical drill, cutters, taps, mills and other tools. At realization of the analysis for last three years, it is established, that the most widespread group of tools are drills. Namely drills in diameter of 7.0-10.0 mm. In Joint-Stock Company " Lugansk factory of cranked shaft" the tool, both factory manufacturing, and purchased is used. The analysis of a way of receipt of the tool in a factory is spent. It is established, that drills in diameter of 7.0-10.0 mm in a factory are made in 3.5 times more, than buy.
Both factory and purchased drills fail owing to breakages. Having analyzed the data of a factory, it is possible to allocate some reasons of failure of the tool. At the analysis of the factory data it is visible, that for the tool received by a traditional way, the most typical reasons of breakages are: twisting at a shaft, further follow non-observance of technology. For the powder tool the fragile break is characteristic.
However, as numerous researches testify, the tool from powder metal has properties relatively to the tool received by methods of processing by pressure, at times and exceeds it.
Preparations for drills have the correct cylindrical form, that it is convenient for deformation, calculations and researches. Hence, expediently to investigate from the nomenclature of the tool of a drill in diameter of 10 mm, from metal received by usual ways and methods of powder metallurgy.
For investigations three drills were taken with different initial diameter. As high speed steel began are difficult wrought material, they are expedient for subjecting hydro extrusion. Samples were extruded, have turned out 3 deformation degree: 15 %, 35 %, 50 %, final diameter of 10 mm. Thus steel Ð6Ì5Ê5 and Ð6Ì5Ê5-MP were used. For comparison of a way of manufacture, a degree of deformation and influence alloying cobalt, steel Ð6Ì5 was took received by methods of casting.
For investigations the samples preliminary cut with the help of the electrospark machine tool of model 4531 were taken. Investigations were made on longitudinal and cross sections of samples.
Measurement of microhardness carried out on device PMT-3 in accordance with GOST 9450-76. Measurement of microhardness was carried out on a method of a restored print, a diamond tip at loading 100 N/mm2.
It is established, that the high speed cutting steel Ð6Ì5 received by methods of casting has the lowest hardness, in comparison with other investigated steel. Steel Ð6Ì5Ê5 as a whole is softer, than similar steel received by methods of powder metallurgy. Also it is possible to notice that with increase of a degree of deformation hardness grows, both for steel Ð6Ì5Ê5 and for steel of Ð6Ì5Ê5-MP.
The microstructure of samples is determined. In steel Ð6Ì5 it consists from eutectic and carbide. A grain has 4th numbers, in accordance with GOST 5639-82. An estimation of size of a grain made on a method of comparison with reference scales, the average area of section of a grain - 0,009 mm2. Carbide heterogeneity - 7-8 points, in accordance with GOST 19265-73, on a scale ¹ 2, at magnification x100. Definition of a microstructure spent on metallurgical microscope MIME - 7.
The microstructure of samples from steel Ð6Ì5Ê5 differs more fine structure, in comparison with steel Ð6Ì5 as steel is alloyed by cobalt. The microstructure of samples from steel Ð6Ì5Ê5 and Ð6Ì5Ê5-MP consists of sorbite and carbide. Carbide has a diverse structure. Meet both fine roundish carbides, and larger angular. Carbide heterogeneity is of 1-3 numbers.
The microstructure of samples from steel of Ð6Ì5Ê5-MP carbide heterogeneity has no, carbide identical roundish forms in regular intervals allocated on a sample plane, are characterized by a high degree of dispersiveness.
On the data of X-ray analysis, in cast high speed cutting steel Ð6Ì5 carbides structure Cr23C6 and carbide of high speed cutting steel are present. Carbide structure of steel Ð6Ì5Ê5 and Ð6Ì5Ê5-MP is identical. It is submitted such carbides, as: Cr23C6, carbide high speed cutting steel and VC. Diffraction records are received on difractometer DRON -3, in radiation of iron.
It is possible to assume, that having applied various modes of heat treatment, thermo- mechanical processing, and also additional local hardening, the microstructure will change, and higher operational properties will be received.