Page 28 - january

METALWORKING EQUIPMENT AND TOOLS

The processing was carried out on a turning
lathe. In order to avoid pulling out the work piece, it
was pressed by the center of the tailstock. A device
was installed in the tool holder, the pressure of the
roller was set, regulated by divisions on the device
(1 division corresponds to a force of 1210 N). Before
the hardening treatment, the outer cylindrical
surface of the MCP blanks was turned to achieve
a roughness Ra = 0.76 μm. During processing,
coolant was supplied to the work hardening zone.
Hardening treatment by surface plastic deformation
was carried out in different modes using rollers:
diameter D = 60 mm and profile radius R = 2 mm,
D = 60 mm and R = 20 mm, D = 60 mm and R =
10 mm, D = 30 mm and R = 5 mm. Because of
the research, it was found that positive structural
changes occurred in the surface layer. The hardness
of the samples has increased. After hardening
treatment, an improvement in roughness from 8 to
79% was obtained. Figure 1 shows the dependence
of the change in roughness Ra on the force P after
rolling in the composite powder material ZhGr1D15.

Conclusion
Based on the experiments carried out, it was found that surface plastic deformation
significantly reduces the roughness of parts made of powder alloys. The optimal modes of
hardening treatment of composite powder materials ZhGr1D15 and Kh11N8D20 by the method
of surface plastic deformation have been obtained.

M.E. Skladanov, postgraduate student.
Scientific adviser: E.Yu. Kropotkin,
Doctor of Technical Sciences, Associate Professor. MSTU STANKIN,
Department "Highly efficient processing technologies".

Literature:
1. Kropotkina E.Yu., Flegentov V.A. Strengthening of parts made of powder alloys by rolling // Bulletin of mechanical
engineering. 2015. No. 8. pp. 35 - 36.

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