Аннотации:
A technique for measuring the mechanical properties of plasma-hardened wheel steel
with nanoindentation is applied. The purpose of the work is to demonstrate and substantiate the
serious differences between the mechanical properties and behavior of materials in nanovolumes from those obtained in traditional macroscopic tests. The features of measuring
mechanical properties – hardness, Young's modulus, elastic recovery – affecting the wear
resistance of the surface layers of the material are given. Measurement of the physic mechanical
properties of the material makes it possible to evaluate and select the optimal technology for
surface modification by surface plasma hardening. It is noticed that the objectivity of
determining the hardness, elastic modulus, elastic recovery and flow stress depends on the
parameters of the measuring equipment used and strict adherence to the requirements for the
imprint depth depending on the thickness of the hardened layer. The studies carried out on wheel
steel samples from the rim and from the ridge of a railway wheel subjected to surface plasma
hardening under the same conditions. The HV and H of the wheel rim are greater than the
corresponding values of the flange, and the young modulus of the wheel flange, on the contrary,
is greater for the flange.
