Analysis of Induction Hardened Cylinders

Induction hardening is used to harden small cylinders of SAE 1074 steel. Parts were quenched with a high concentration of a PAG type quenchant. Soft spots were found on a small percentage of the parts. These soft spots were consistently at one location about 2/3 from the bottom of the part. These soft spots were circular, and consistent in size. Product was examined and determined to be adequate and to specification. Using a lower concentration of quenchant, the quench speed was increased. While this reduced the number of soft spots, it did not completely eliminate the soft spots. Faster quenches were tried with similar results. Using Transvalor SIMHEAT, we were able to duplicate the results, and eliminate the source of soft spots.