Abstract
Hardness values of a steel can be estimated from the CCT diagram if the cooling curve of the specimen is known. By the use of the master cooling curve previously obtained by the present anthors, it was found that the cooling curve at any position from the quenched end of a Jominy specimen and hence the Jominy hardenability curve could be estimated accurately. These estimated curves of several steels well coincided with the measured results. Several estimation methods proposed by other researchers were compared with the one from the master cooling curve.
