Abstract
The effect of carbon on the allotropic transformation of cobalt is thoroughly investigated by means of microscopie, dilatometric and magnetic analyses, and a revised. equilibrium diagram is proposed. The allotropic transformation point of cobalt lowers at first with the increase of carbon and reaches the lowest temperature at about 0.1% C. With a further increasing content of carbon the transformation point rises, and by the peritectoid reaction at 502° and 0.27 per cent carbon α-phase decomposes to β-phase and graphite. According to the cooling curves, the transformation point lowers with the addition of carbon and at 0.25% C and 341° a eutectoid reaction occurs.
