PROTECTING OF HIGH-STRENGTH CAST IRON PARTS FROM HYDRO ABRASIVE WEAR THEREOF BY COMBINED ENVIRONMENTALLY SAFE METHODS

Abstract

There has been proposed a new technology for protecting the parts made of high-strength cast iron. The technology
consists in electrospark alloying (ESA) of the part surfaces with aluminum followed by applying a special layer thereeon with
the use of an electrode made of 90%VK6+10%1M composite material. Onto the formed coating, there is applied a metal-polymer
material (MPM), reinforced with WC and ZrN powders or their mixture, which has been added to a two-component epoxy
system filled with Loctite 3478 ferrosilicon at the concentration of the reinforcing substances of ~ 80% WC; 80% ZrN and
40%WC+40%ZrN, respectively. After that, a portion of the MPM layer is removed by grinding it up to the applied coating
roughness protrusions.
Comparative examinations have established that for the high-strength cast iron of VCh50 grade, in terms of hydro
abrasive wear resistance thereof, the best results had been achieved by the specimens with the coating formed in the sequence
of ESA Al → ESA (90% VK6 + 10% 1M) → MPM (80% ZrN), the wear of which was 97.1% less as compared to the specimens
without coatings, 44.1% less as compared to the prototype (the specimens of 12Х18Н10Т steel) and, accordingly, 5.9 and 14.7%
less as compared to the specimens with the coating formed in the sequence of ESA Al → ESA (90%VK6+10%1M) → MPM (40
%WC+40%ZrN) and in the sequence of ESA Al → ESA (90%ВК6+10%1М) → MPM (80% WC).