INDUSTRIAL SCALING OF LOW-FRICTION HYBRID LAYER
TECHNOLOGY ON PISTON RINGS

Technological trials of gas sulphonitriding processes for cast iron piston rings were carried out as an alternative
to chromium electroplating for the production of low-friction layers. The effectiveness of different ways of
packing heat treatment charges in minimising or eliminating deformation of the rings was compared, and
the effectiveness of ring packing with restraining tooling was confirmed. The maximum duration of the gas
sulphonitriding process was determined at 1 hour, both as a stand-alone process and as a component process
in a multi-stage technology for the manufacture of low-friction hybrid layers, ensuring the maintenance of
sufficient ring toughness for an opening during assembly.

