Factors Controlling the Graphitization at Subcritical Temperature of High Carbon Steel (Part-2)

Study on the graphitization of high carbon steel-I

Abstract

The authors studied other factors controlling the graphitization of high carbon steel at subcritical temperature in sequence of the first report (Tetsu-to-Hagane Vol. 44, No. 10 p 1180). The results obtained were as follow:
(1) Cold deformation had an accelerating effect on graphitization and compressive forces were as effective as the tensile strength in promoting graphite formation.
(2) The heating at 870°C and furnace cooling after cold drawing inhibited markedly the graphitization on subsequent heating at 650°C.
(3) Hydrogen, when used as annealing atmosphere at 650°C, had a stabilizing effect on the carbide and inhibited graphite formation. Nitrogen atmosphere and vacuum had no effect of stabilizing carbide.
Cast iron chips used as packing material caused a less graphitization than nitrogen atmosphere or vacuum.