A Study on an Energy-saving and High-efficient Pack Boriding Technology for Tool and Die Steels

Alternating current field (ACF) enhanced pack boriding was carried out on three kinds of tool and die steels of T7, T12 and W18Cr4 V at low and moderate temperatures. A column-shaped electrode was positioned in the center of a pack container, the wall of the container was taken as another electrode. Samples and the boriding agent were set between the electrodes. The test results revealed that the ACF with a current of 4 A and a voltage of 30∼50 V enhanced the boriding of those tool steels. Compared with the conventional pack boriding, the case thickness of the sample was increased by more than 70% by ACF enhanced pack boriding. The case microstructure was improved to some extent. With the new boriding technology, the treating temperature can be lowered, the soaking time can be shortened, and the utilization ratio of agents can be increased. Preliminary analysis has been made on mechanisms of ACF's effects to the pack boriding.