Rolling technology
Why roll?
The build up of material duringchamfering on the gear lateral surfa-
ces is removed during the deburr operation. The rolling operation on
the other hand serves to remove the
build up of material on the tooth
flanks (secondary burr) which is cau-
sed by plastic deformation during
chamfering.
Secondary burr during chamfering Deburring the secondary burr
on gear lateral surfacesRolling the secondary burr on gearflanks
Problems in subsequent operations
As a rule burrs which are larger than
0,05 to 0,07 mm can create pro-
blems during subsequent phases of
production leading to shorter tool life
and often the tool itself may be
endangered. In this case a rolling
operation is strongly recommended
and is at times crucial.
Not heat treated, 2% Nital tested, Ferrite structure with a 25% Pearlite portion
Heat deformation =
hardening crevices?
If tools are chamfered and rolled
when they are soft, a change in
structure in the form of compression
may occur. The levelling out of the
secondary burr during rolling causes
the material to sink.Our research shows that hardeningcrevices do not appear after heat
deformation. After heat treatment no crevices form
in the rolled zone and the structure of
material is normal, depending on the
properties of the steel itself.
Tooth chamfers after chamfering and rolling, Ferrite structure with a 25% Pearlite portion, compressed due to the pressure exerted by the
chamfering tool Tooth chamfers after chamfering, Nital tested, Ferrite structure with a 25% Pearlite portion, compressed due to the pressure exerted by the
chamfering tool Tooth chamfers after chamfering, rolling and hardening, Nital tested, martensitic structure with a 6-7% austenitic portion
