Fundamental Study on the Tufftride Process

Abstract

The fundamental investigation on the Tufftride process, which is widely applied in this country, was performed.
The results obtained are summarized as follows:
(1) The aeration of the Tufftride bath has to be carried out in order to ensure a good nitriding performance.
(2) However, there must be an upper limit to the amount of air bubbled through the bath, since an increased aeration also involves an increased consumption of salt bath constituents.
(3) The nitriding reaction in the Tufftride process can be considerably promoted, if the Tufftride treatment is carried out at temperatures above 530°C.
(4) The accelerated nitriding reaction can be explained by considering the interface nitrogen concentration which increases linearly as nitriding temperature becomes higher.