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ITAN • Autumn 2012 • www.itatube.org
ITAN
slices: Investment for Equipment and
Fixed Operating Cost.
For DANIELI FRT™ the Investment for
Equipment is less because the number
of stands required to perform the same
wished reduction are less. It is a direct
consequence of the higher reduction
per stand we can achieve.
Regarding the Fixed Operating Parts
Cost, less stands means less cartridge
series, less equipment to manage, less
storage space, and at the end less
number of pieces to be handled.
In fact finishing stands are not any
more three but two.
For both costs and technological
purpose we have to consider that we
proved with the same pass design we
can roll a wider range of products,
avoiding specific stand setups for small
ranges.
This matter joined with the possibility
to adjust the roll, gives a huge cut to
the initial Fixed Operating Parts Costs,
lightening the initial investment.
Even in Variable Costs DANIELI FRT™
brings lot of advantages in hot rolling
field. In fact another matter which has
to be considered for cost analysis is the
tooling wear.
More uniform speed on different rolls
areas means less roll wear. It causes
indirectly an extension of the mill
availability in “Ready to Roll” state, with
more pieces processed in the TBM
(Time Between Machining).
Finally a quick reminder of the energy
saving during rolling we can achieve.
The reasons for that are explained
above. Just to consider that we are
both producing and saving money at
the same time.
Conclusions
We deeply study market requests and
we know the needs of our customer to
have more and more flexible equipment
for high production rates and high
performances at low cost. For that we
developed DANIELI FRT™ which is the
new four roll technology for extracting /
sizing/stretch reducing mill.
We built up a new simulation system
able to predict the behaviour of the
material during rolling and to prove
different mill configurations. We
performed several tests mainly devoted
to stress both mechanical equipment
and technological features. In other
words we tried the effectiveness of our
studies and the robustness of the mill.
At the end we succeded in all our
targets, moving forward the boundaries
for hot rolling OD finishing.
Concluding the main advantages of
DANIELI FRT™ vs two and three roll
technology are:
• Better geometrical tolerances both
for diameters and wall thickness
distribution across the section
• In case of thick wall tube rolling,
the internal shaping of the tube
is improved, reducing the risks of
internal polygonalisation of the tube
• Possibility to roll tubes with heavier
wall thicknesses, because of the less
trend to internal polygonalisation
• Less trend of the material to overfill
the roll gap
• Higher stretches among the following
stands can be performed
• Higher outside diameter reduction
per stand can be performed
• Less roll wear because of the more
uniform peripheral speed along the
roll groove (bottom roll groove in
respect to the roll sides). Moreover
the material drag effect is increased,
with better surface quality of the tube
rolled
• Very limited risk of material squeezing
by the roll sides (material pinching)
• Increased re-utilisation of a stand
due to reduced ovalisation of the
groove opening or closing the rolls
• Significant reduction of tooling cost
thanks to the reduced roll wearing
• Reduced number of finishing stands
Danieli Centro Tube – Italy
Fax: +
Email:
Website: www.
Tolerances: DANIELI FRT™ vs Two and Three Rolls Technology
Rolling tests in different phase: pipe biting and rolling for three stand mill setup