Structural changes in steel R6M5 due to surface melting by electron beam

Abstract

When high speed steel R6M5 is molten by an electron beam, rapid cooling has the result that in the process of crystallization a finely disperse structure forms, and the width of the secondary branches of its dendrites depends on the cooling rate in the process of crystallization. In the molten zone we find finely disperse metastable carbide type M2C, the content of alloying elements (W, Mo, V) in the solid solution increases, martensite forms, both rack and lamellar one. In addition to that, δ-ferrite, was discovered in the molten zone; this is ascribed to the suppression of the peritectic reaction.