MODIFICATION OF CHROME-VANADIUM WHITE IRON COATINGS BY IMPULSIVE ELECTRON-BEAM PROCESSING
Bair Dampilon1, Alexey Tolstokulakov2
1associate professor of Institute of high technology physics, National research Tomsk polytechnic university, scientific associate of Institute of strength physics and material science SB RAS, PhD, Tomsk , Russian Federation e-mail: dampilon@ispms.tsc.ru
2student of Institute of high technology physics, National research Tomsk polytechnic university, Tomsk, Russian Federation e-mail: Ist.Jimmy@mail.ru
Abstract. Results of investigation of effect of impulsive electron-beam processing and following annealing on structure and hardness of hardfaced chrome-vanadium cast iron coatings are presented in given paper. The coatings were obtained by electron-beam hardfacing on low-carbon steel substrates. After grinding surfaces of the coatings were locally processed by impulsive focused electron beam with discrete point distribution in a square packing on the surface area. The research results showed that the modified zones consist of two phases. The first phase is supersaturated austenite. The second phase locally distributed in the volume of modified zone is the nucleation centers of eutectic. Results of measuring by NanoTest system showed that modified zones have low values of hardness. Low hardness values are probably caused by presence of significant volume of supersaturated austenite in modified zone. Following annealing of specimens led to significant increasing of hardness of modified zones. As a result of the annealing (500ᴼC) supersaturated austenite is decomposed on eutectoid with nanoscale structure components. Increasing of the annealing temperature up to 1100ᴼC results in decomposition of supersaturated austenite, growth and coagulation of carbide phase in the modified zones.
Keywords: impulsive electron-beam processing, hardfaced chrome-vanadium cast iron coatings, modified zones, supersaturated austenite, annealing, eutectoid with nanoscale structure components, hardness.
