Case Studies
Case Study One
Automobile Gears
Material SAE M1010, C10
High speed gears require high root and
flank stiffness to prevent bending fatigue,
and a high surface hardness with a low coefficient
of friction to resist abrasive and adhesive
wear. Quiet running requires a surface hardening
heat treatment that precludes dimensional
distortion and loss of surface finish.
The ELTROPULS plasma nitriding process,
compared to salt bath nitriding, produces
a more uniform compound zone with less dimensional
distortion for improved resistance to wear
and for silent running.
Pretreatment: No heat treatment
Previous Treatment: Nitrided in
a salt bath (18 microns +/- 4)
Present Treatment: ELTROPULS plasma
nitriding
Treatment Parameters: T = 1070 F/
p = 3 mbar / t = 8 h
The following benefits can be obtained
by selecting the ELTROPULS process:
- A compound zone thickness of 18 microns
+/- 1 micron, with this uniformity extending
over the entire gear profile.
- A surface hardness between 720 - 750
HV.05, measured both on the gear flank
and at the root.
- No dimensional change or distortion
of the gear profile from the heat treatment
- The elimination of salt deposits from
the gear surface and, therefore, the elimination
o environmentally sensitive cleaning operations
after the nitriding step.
Case Study Two
Extrusion Dies
Material: AISI H13 Hot Work Steel, X40CrMoV51
Extrusion dies must operate under a large
amount of thermal stress and mechanical
pressure. They require high surface hardness
in their bearing area to prevent loss of
dimensional tolerances from erosive wear
while pressing thin sectioned aluminum shapes.
ELTROPULS plasma nitriding permits the
selection of the more ductile gamma prime
compound zone and a diffusion zone for longer
die life and increased extrusion speeds
in most applications.
Pretreatment: Hardening and tempering
to 36-38 HRc
Previous Treatment: Salt bath nitriding
Present Treatment: ELTROPULS plasma
nitriding
Treatment Parameters: Temperature
1005 F, Time 9 hours
The following benefits are available with
the introduction of the ELTROPULS process:
- Extrusion die life has been increased
by 80%, often with higher extrusion speeds.
- Complex profiles, with a narrow openings
to bearing surfaces, can be reliably nitrided.
- A uniform compound zone can be produced
on all surfaces.
- Die surfaces can be effectively protected
from both the abrasive and adhesive wear
of aluminum extrusion.
- Molten salt can be eliminated from the
heat treating operation and dies will
require no cleaning inside narrow profiles
after completion of the nitriding operation.
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