PLASMA NITRIDING (the Blue
Glow Process), also known as CASE HARDENING is a thermochemical
diffusion process that creates a cased hardened layer by changing
the chemical structure of the surface of a component. Recommended
applications include valve springs, retainers, spring seats and
crankshafts. Nitriding is used on components with a ferrous base
and can be very carefully controlled to impart a precise case depth.
This allows the component to resist abrasion and reduce the materials
tendency to gall when in use.
This process will extend the fatigue life of the component being
treated and is used when the product experiences extreme loading
or torque or when the core hardness does not lend itself to supporting
a PVD coating.
During The Plasma Ion Nitriding Process, The plasma nirtriding
process is a thermochemical diffusion process that creates a
cased hardened layer During the plasma ion nitriding process
components are placed into the chamber and the atmosphere is
removed. The chamber is back-filled with a hydrogen gas and the
components are heated to between 900 and 950 degrees Fahrenheit.
A plasma is generated by an electrical charge that is applied
to the components. A gas mixture containing nitrogen is introduced
and the nitriidng cycle begins.
The nitrogen present reacts with
iron in the steel to form a compound layer on the surface of
iron nitride. This surface layer is the supply for the nitrogen
to diffuse into the surface and react with the nitride forming
elements.
The nitriding forming elements that must be present
include chromium, titanium, aluminum and vanadium. A constant
supply of the gas mixture is supplied to the chamber to sustain
the nitriding process and produce a uniform case depth. When
the designated processing time has elapsed the plasma is extinguished
and the product is allowed to cool.
Our gamma prime layer is used when a small white
layer build-up is required and where impact may be a concern.
Our epsilon layer is used on low alloy steels,
cast irons and when a thick white layer is necessary.
Our duplex layer is used when we will be applying
one of our PVD coatings to the surface of a material that will not
provide sufficient support. The hard case developed from the nitriding
process provides a hard surface for the PVD coating to bond to.
