Abstract: A new LT process has been
established after the study of Z-1 regenerated salt, the
composition of bath, the preferred selection of process
parameters, various examinations of properties and production
practice. The structure of Z-1 regenerated salt, which possesses
the quick-action and stability to adjust the content of molten
bath, has been analysed by means of infrared spectra. Molten
bath and regenerated salt have now been commercialized. By EPM,
EDX and X-ray diffraction analyses, it is found that there exit
S, N, C and O in the codiffused layer, with FeS-rich being on the
surface. From the tribolgical viewpoint, the property of S-N-C
codiffusd layer with LT treatment has been investigated, which
shows that the hardness gradient conforms with Amontons Law. The
LT treated workpieces made of different materials have good
anti-friction, anti-seizure, anti-wear and anti-fatigue
properties which are of crucial importance to improve the
service reliabilities of high-Cr stainless steel frictioal-pairs
(e. g. gears and impellers) and 0.45%C steel energy=regulating
valves in refrigerator, and to increase the life of high-speed
steel cutting tools and high-Cr steel dies, which may produce a
great economic result. Three compositions of molten bath and
methods of ventilation have been established to meet the
requirements for various steel workpieces. The process is
characteristic not only of stable treatment and extensive
application, but also of non-pollution for water and atmosphere.
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