MICROSTRUCTURAL STUDIES OF A ROLL-BONDED LAMINATED ULTRAHIGH CARBON-STEEL BAR

The microstructure and hardness of a metal matrix laminated composite, containing an ultrahigh carbon steel and medium carbon steel, is examined and evaluated. The composite, in the form of a round bar, is made by a novel method using a helical radial-shear rolling process developed in the Soviet Union. The as-hot-rolled laminate is shown to have a high hardness of HV = 500 in the ultrahigh carbon steel region, which is attributable to the fine microstructure consisting of eutectic carbides, a discontinuous network of proeutectoid carbides, and ultrafine pearlite.