Влияние непрерывной и импульсной электронно-лучевой обработки на покрытие из хромованидиевого чугуна

Abstract

The paper reports the results of an investigation of structure formation in the eutectic chromium-vanadium cast iron coating deposited by electron-beam hardfacing (EBH) and subjected to multipoint pulsed electron-beam treatment (MPEBT) of the surface layers. The coating material structure in the zones modified by MPEBT changes considerably, showing the presence of a large amount of supersaturated austenite matrix and eutectic colonies in the form of fine isolated inclusions. The eutectic colonies are fan-like. The leading phase in the eutectic colonies is vanadium carbide. After aging within the temperature range from 900 to 1100°С the structure of the modified zones exhibits a large amount of fine secondary carbides Cr7C3 rejected from the matrix. The secondary carbides are uniformly distributed in the bulk of the modified zones. The matrix after aging undergoes [gamma]->[alpha] transformation and mainly has the martensitic structure. Aging increases significantly the hardness of the modified zones and abrasive wear resistance of the entire coating.