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Actual Problems in Machine Building. Vol. 4. N 1. 2017
Materials Science
in Machine Building
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130
TECHNOLOGICAL FEATURES OF THE HEAT TREATMENT OF DETAILS
RESTORED WITH ELECTRIC CONTACT SURFACING
Berezshnaya O.V.
, Ph.D. (Engineering), Associate Professor, e-mail:
elena_kassova@mail.ruDonbass State Engineering Academy, 72 Shkadinova, Kramatorsk, Donetsk region, 84313, Ukraine
Abstract
The influence of heat treatment on the structural changes of the deposited layer on the surface of
structural steel components, remanufactured electric contact deposition is investigated. Preliminary
experiments showed that high-frequency heating since the total number of free ferrite in the
structure of the deposited layer is somewhat smaller than in the conventional furnace, thereby
increasing the propensity to stress concentration in the restored product. To obtain the desired
structure it is suggested to provide a cooling of the deposited samples at slower rate after induction
heating. As a result of quantitative metallographic analysis found that the use as a cooling
environment of silver particulate graphite ensures slow cooling of the deposited specimens after
heat treatment, thereby increasing the content of excess ferrite in deposited layer. Also slow
isothermal cooling environment leads to a significant increase in grain size as compared with the
grain obtained by cooling the deposited samples in air.
Keywords
slow cooling, heat treatment, electric contact surfacing