Abstract
Cr-containing Vicalloy specimens composed of 2∼4%Cr, 4∼8%V, (6∼12%Cr+V), 52%Co, balance Fe were air-cooled from 1100°C, reduced to 75∼94% by cold working and then subjected to tempering at temperatures between 100° and 800°C. The changes in the saturation induction, residual induction, coercive force, thermal dilatation, electrical resistivity and mechanical hardness of Cr-containing Vicalloy during tempering were determined. The transformation temperature range between heating and cooling is large in Vicalloy containing 9% (Cr+V). By tempering at about 400°C after cold-working, the saturation induction, electrical resistivity and lengths of specimens increase a little larger than those in the cold worked state. It is caused by the ordering of the alpha phase during tempering. The alpha phase is transformed partially to the gamma phase by tempering at 550°∼650°C, so that the electrical resistivity and lengths of specimens decrease and the coercive force increases. When the Vicalloy containing 12% (Cr+V) is tempered at a higher temperature for a short period after cold working, the maximum of coercive force is higher. However, the maximum value of the coercive force of an air-cooled Vicalloy containing 9% (Cr+V) hardly depends on the tempering temperature .
