A complex project

KOCKS and their project partner had to manage the logistics of a personnel-intensive project with a great many unknowns. BENTELER was pleased to note that the project was delivered on time, on target and on budget.

COMPANY BACKGROUND

With about 30,000 employees and 153 locations in 40 countries, the BENTELER-Group stands for a high degree of excellent material, production and technology in the areas of Automotive, Steel/Tube and Distribution. The three Business Divisions BENTELER Automotive, BENTELER Steel/ Tube, and BENTELER Distribution are organized under the strategic management holding company BENTELER International AG. Continuing progress by means of new materials, technologies, and products as well as long-term, profitable growth are the supporting pillars of the 140-year success story of the BENTELER-Group, which is in its fourth generation of family ownership.

PROJECT BACKGROUND

The decision to site and construct a production site in the U.S. was an important element of BENTELER Steel/Tube’s global business growth strategy, strengthening the company’s position in the North American oil country tubular goods (OCTG) market. The new plant in Shreveport (Louisiana) was designed to produce seamless tubes in the size range 26.7 – 139.7 mm, with the focus on OCTG. The mill however was also designed to be flexible and produce tubes of other specifications and for other markets, e.g. the automotive industry or the energy industry. This flexibility and the ability to produce even small batch sizes economically is a defining feature of the success of the BENTELER business model. The latest generation of the KOCKS Stretch Reducing Block – SRB® 3.0 – in size 315/30 with its automation system was the perfect fit for the BENTELER vision. KOCKS chose here to further develop their tried and tested Star Drive design with individually driven rolls. The combination of high-strength and high-precision roll stands with the absolute latest in automation technology enables BENTELER Steel/Tube to produce seamless tubes of the very best quality, with optimum efficiency.

PROJECT EXECUTION

One of the most challenging aspects of this assignment was its sheer complexity, mainly due to the fact that the project involved a greenfield site in the USA.

KOCKS had to manage the logistics of a highly personnel-intensive project with a great many unknowns.

BENTELER was pleased to note that, despite its complexity, the project was delivered on time, on target and on budget.

IMPORTANT NOTE

BENTELER’s decision to use the latest generation of the KOCKS 3-roll technology puts the following innovative features at their disposal:

  • KOCKS’ precision quick roll changing feature is the basis for individual roll machining outside of the roll stands on a conventional CNC lathe. Thus, it is possible to cut multi-radii roll profiles without any limitations caused by the machining process. Multi-radii pass designs increase the working range of the calibration in terms of the wall thickness-to-diameter ratio of the tubes. This leads to significantly increased mill utilization and reduced operating cost.
  • The pass diameter of the SRB® finishing stands is adjustable. In conjunction with the remote control system it is possible to modify the finished tube diameter in a certain “free-size range” from the pulpit without interruption of the production cycle. In this way, there is no need for special finishing passes, e.g. for slightly oversized tubes or for different grades. This fact along with the individual roll machining outside of the roll stands is the reason why the total number of roll stands required is 50%-70% less than that of traditional rolling mills.
  • The proper roll alignment in the roll stand is measured, adjusted and recorded on CAPAS (Computer Aided Pass Adjustment). Furthermore, the pass diameter of the adjustable roll stands is set to the required value on CAPAS. In this way, all rolling stands are sent from the roll shop to the rolling line perfectly adjusted and ready for operation. This makes CAPAS an active feature of KOCKS’ quality assurance policy.
  • The latest generation SRB® roll stands are equipped with an innovative new sealing system for the bearings.
INNOVATION INSIDE
  • The rolling mill for this assignment was a completely new design, developed to be space saving and low-maintenance.
  • The innovative design in combination with the state-of-the-art rolling process control makes the SRB® 3.0 an essential and reliable part of premium quality seamless tube mills.
  • The highly efficient HEC (Heavy End Control) minimizes the crop end losses and is indispensable for an economical production.
  • The latest generation of AWC (Automatic Wall Thickness Control) successfully homogenizes the progression of the wall thickness over the entire length of the tube. Geometrical variations from the piercing or elongation process are significantly improved even over large lot sizes.
  • For the first time a dust extraction hood has been integrated directly into the SRB® in order to comply with strict US environmental regulations.