Rolling Mill

     Rolling Mill is the production unit, in which the billets produced in the steel plant is rolled to the customer required sections and sizes in the range of standards.

     Quality steels should be rolled with modern techonology and high production yield. So ÇEMTAŞ has modernized the Special Quality Steel Rolling Mill in 1998 with wide range of different sections and sizes. Çemtaş Special Quality Steel Rolling Mill is a must for the production of high quality steel with the capacity of 210.000 tons/year and automation systems of level 1 and level 2.

Rolling Mill consists of units below;

Walking Hearth Reheating Furnace ( Thyssen)

  • 50 tons/h capacity
  • Furnace atmosphere and temperature control by manually and automation.

    Descaling Unit (Hermetic)
  • 400 bars water pressure.
  • Scale free billet surface.

    Roughing Mill (Demag)
  • Three stands three-high mill.
  • Bar turners for the movement of billets automatically without man power.

    Continuous Mill (Demag)
  • Six stands (three horizontal and three vertical).
  • Automation controlled.

    Bar Gauge (IPL-Orbis)
  • 100% measurement.
  • 2000/sec measurement frequency.

    Cooling Bed (Demag)
  • Different cooling speed possibility for the different quality groups.
  • Additional slow cooling covers for the controlled cooling.
  • Piling and double notch possibility.

     

    Shot Blasting and Straightening

  • Two shot blasting machines (Schlick and Endumak)
  • Two straightening machines (Bronx and Kieserling)

  • Integrated Non- Destructive Testing Devices

  • Three surface crack testing device (Foerster)
  • Three ultrasonic inner defect testing devices (Krautkramer)
  • Three mobile spectrometer
  • Magnatest

    Walking Hearth Reheating Furnace

         The billets from steel plant is reheated to the rolling temperature with the capacity of 50 t/h.

         It is possible to control the temperature of the furnace in four zones, inner pressure, combustion air and waste gas temperatures, air and gas amounts by manually or computer. By these controlled parameters, the amount of the scale on the billets is low. Low scale not only reduces production costs because of the low material loss, but also prevent the possible defects caused by scale on the surface.
    Reheated billets exit from furnace and come to the descaling unit for the scale cleaning.

    Descaling Unit

         Scale formed during reheating on the surface of the billets is taken out by 400 bars pressure of water sprayed by 16 nozzles to the four surfaces of the billets. By the taken out of primary and secondary scales, the surface cleanness of the billets is ideal for rolling.

         By scale free billet rolling, some possible surface defects and cracks caused by scale on the surface is prevented.

    Roughing Mill

         It is the unit with three stands three-high mill for the preforming and presizing of the billets before continuous mill. Turning and feeding of the materials to the rolls is done by the remote controlled bar turners.

    Continuous Mill and Bar Gauge

         Continuous mill consists of three horizontal and three vertical, totally six stands. It has been founded in 1998 with modern technology for the capability of the precision sizing production. Material flow, speed and other parameters are simulated on the screen at the same time with the production, and by this way online control is possible.

         Every produced bar is 100% measured by bar gauge, after the last continuous stand. Bar gauge, according to the standards, measures the favorableness of the materials with 2000/sec frequency by the technique of two camera lightning. By this computer controlled system, produced material is under control according to the standards. Produced bar is cut to the length of 25 to 42 m. by rotary shear after bar gauge.

    Cooling Bed

         Cooling bed in Cemtas is rare in the steel sector with its covering system and special design. Piling/double notch system is designed for the slow cooling by the cooling of material in contact with each other. During spring flat production, by piling/depiling system, flat products are taken to the cooling bed with two layers, one on the other, and slow cooling is achieved.

         During round production, by double notch system, round products are taken to the cooling bed with two materials are in one notch, and slow cooling is achieved.

         Addition to these systems, there are covers for the additional slow cooling and for the controlled slow cooling of the steel qualities that gets harden in air.

         Designation of the cooling speed according to the steel quality groups, supplies the control of all parameters during cooling.

    Shot Blasting Machines

         Çemtas has two shot blasting machines. Shots are blasted on to the material and the scale on the material is taken out. Scale free surface of the products is important for the detection of the surface defects in the non destructive testing machines. Surface quality of Sa 2,5 standard is achieved.

    Straightening Machines

         Çemtaş has two straightening machines. The round product in the size range of 15 – 110 mm is straightened with the 1 mm/m precision. The material is straightened by the three point contact loading with the special designed straightening rolls. During straightening, material is turned for straightness homogeneity. The important characteristic of our machine is improving the surface quality by taking out of the scale during straightening.

    Surface Defect Testing Device

         Çemtas has three testing devices from the company of Foerster from Germany. Two of them are Circoflux S 6.144 and one of them is Circoflux DS. These test machines has the best references all over the world. Circoflux detects the surface defects on the material which has surface quality of SA 2,5. Surface defects control is done according to the standards which is suitable for the customer requirements and specifications. During testing, there is magnetic current during the passing through of the material and the differences in the intensity of magnetic current in the surface flaw region is detected by the probes which are in contact with the material.

    If the detected surface flaw is out of tolerances according to the standards, this defect region is colored automatically and collected separately from flawless material into the different collecting cradles.

    Ultrasonic Inner Defect Testing Device

    Çemtaş has three GE IT(KRAUTKRAMER) type ultrasonic testing devices which the models are respectively USIROB 140 SE, ROB 65 VIS and ROWA B90 PAT.

         Ultrasonic testing is not only used for determining internal defects but also determining for surface and sub-surface defects too. The probes used within The ROWA device are based on new technique called Phased Array technology The ultrasonic sound waves produced by these probes, passes through a circulating water bath which surrounds the material that is going to be tested. As ultrasonic sound wave propagating through the specimen, it gives an echo from the discontunities in the material and according to the type of discontinuity the defect determined place is colored automatically

    Mobile Spectrometer

         Çemtaş, has three mobile spectrometers, one of them is SPEKTROSORT and the other two are WAS made.

         The mobile spectrometer is used in order to prevent mixing of the bars that are ready for shipping. The device is calibrated for the quality of the material that is going to be controlled and the every single bar in the bundles are controlled % 100.

    Magnatest

    Foerster product Magnatest DH 3.633 is used to separate the metals according to the physical properties like permeability and electrical conductivity. Every tested bar goes through the magnetic field that is produced within the coil. According to the type of material, permeability and electrical conductivity of materials differ by the magnetic field effect. This utility of materials is used to seperate the mixed bars

    Heat Treatment

         The available heat treatments in Çemtaş are softening, stress relieving and cold shearibility annealing.