Our entire production process—from casting to machining—is carried
out with a focus on precision, durability, and quality. In our
modern facilities, high-alloy rolls are meticulously crafted.
Casting
The temperature of the molten metal is measured using
immersion-type thermocouples, and casting begins at specific
temperatures determined for each chemical composition. Depending
on the type of roll, the casting process is carried out either
from the bottom or the top. By allowing a portion of the molten
metal to overflow, discontinuities that may occur in the body
and neck areas of the roll are prevented.
Raw Materials
At ARDÖKÜM, we believe that producing high-quality rolls starts
with the reliable and premium supply of raw materials. That’s
why we collaborate with the most trusted and high-quality
suppliers in the industry.
The steel scrap used for melting and alloying, along with the
sand, resin, feeder sleeves, and mold coatings used in molding,
are sourced from leading companies in their respective fields.
No compromises are made in maintaining quality throughout the
supply process.
The steel scrap delivered to our scrap yard is subjected to
chemical analysis in our laboratory using an optical emission
spectrometer to ensure it meets the required quality standards.
All inspection results are documented in detail. Ferroalloys,
metallic materials, and molding raw materials are accepted only
after thorough certificate verification.
Melting
With 5 induction furnaces, ARDÖKÜM can obtain up to 37 tons of
molten metal in a single charge.
Throughout every stage of the melting process, the chemical
composition of the molten metal is precisely monitored to ensure
that the alloying elements meet our strict quality standards.
Thanks to the advanced technology of our furnaces, our charging
systems, and our melting expertise, every moment of the process
is carefully controlled, guaranteeing the homogeneity of
alloying elements.
Depending on the type of molten metal, spheroidization,
inoculation, deoxidation, and grain refinement processes are
carried out in specially designed treatment ladles. The treated
molten metal is then transferred to the casting ladle.
As each step is performed in a precise sequence, the
effectiveness of the spheroidizers, inoculants, and grain
refiners is maximized.
Molding
Molding is divided into two parts: the roll body and the necks.
Roll bodies are cast into metal molds coated with special
materials containing zirconium, silica, and graphite to ensure
rapid cooling of the molten metal. Necks, on the other hand, are
cast into sand molds that allow slow cooling to achieve high
mechanical properties.
Our gating system, which directs the molten metal
into the mold cavity, is designed to generate maximum vortex
flow as the metal moves through the mold. This helps concentrate
inclusions that could cause segregation in the center of the
mold cavity, allowing them to be expelled from the mold at the
end of the casting process.
All mold components are
assembled inside casting pits to ensure casting safety, and the
process proceeds to casting after setup is complete.
Heat Treatment
In spheroidal graphite (sphero) rolls, stress relief heat
treatment or prolonged tempering is applied to eliminate
internal stresses caused by high alloy content and casting
techniques, to transform retained austenite—resulting from high
nickel and molybdenum content in acicular grades—and to temper
martensite.
In certain grades, normalization at high temperatures followed
by stress relief heat treatment is required to break down metal
carbide networks formed along grain boundaries and redistribute
them spherically within the matrix.
In our foundry,
we have 2 electric and 5 natural gas-powered heat treatment
furnaces. The electric furnaces are PLC and thyristor
controlled, with temperature measured and managed in three
separate zones. The natural gas furnaces are operated with two
1000 kW burners and are PLC-controlled across five zones. All
furnaces are equipped with internal fans to ensure uniform
temperature distribution.
Machining
In our machining workshop, we are capable of processing every
detail of the rolls and rings required by the iron and steel
industry with precision and accuracy. At Ardöküm, we never lose
sight of the fact that faster, more precise, and more
cost-effective machining is always possible. We continue our
efforts in this direction by closely following the latest
advancements in tooling and machine technologies.
Our machining and chip removal department consists of six
sections:
– Rough Turning / 50 universal lathes with a max diameter of
1600 mm and max length of 6000 mm.
– Length Finishing / 5 universal lathes.
– Finish Turning / 13 CNC lathes with a max diameter of 1600 mm
and max length of 6000 mm.
– Cylindrical Grinding / 3 external cylindrical grinding
machines with a max diameter of 1300 mm and max length of 6000
mm; 1 internal cylindrical ring grinding machine with a max
diameter of 1100 mm and max length of 800 mm.
– Vertical Turning / 4 vertical lathes with a max diameter of
3200 mm and max height of 1800 mm; 2 CNC vertical lathes.