МЕСТНОЕ ОПЛАВЛЕНИЕ ПОВЕРХНОСТИ ИНСТРУМЕНТАЛЬНЫХ СТАЛЕЙ ЭЛЕКТРОННЫМ ЛУЧОМ. 1.Ч. Mestnoe oplavlenie poverhnosti instrumental'nyh stalej ęlektronnym lučom. 1. č.

Abstract

In this work the effect of local surface melting of high-speed steels by high-energy electron beam was investigated. As a result of local electron beam melting and rapid cooling the microstructure in the melted surface zone of high-speed tools steels turned into very fine dendritic structure with great number of fine carbides. The relative content of alloying elements in the melted zone increased, the distribution of elements were more homogeneous. In this case the toughness, the strength at elevated temperatures, the tempering resistance of the melted zone and the tool life increased. The observation in this work point out the secondary dendritic arm spacing (d) is dependent on cooling rate (v) at the solidification.