CD-Laboratory for Materials Modelling and Simulation, Module 5: Online simulation of seamless pipe production within the process chain

voestalpine Tubulars is a world-renowned producer of high-quality seamless steel pipes. Plant in Kindberg (Austria) produces seamless tubular products with an outside diameter up to 177.8 millimeters (7 inches). The maximum capacity of our hot pipe production, boiler tube finishing department and OCTG (oil country tubular goods) finishing department operations is around 350.000 mtons a year. The products are of unalloyed or medium-alloyed steel, manufactured to all international standards. Today the mill is operating at the highest technological standards. For example: A sophisticated energy management system ensures an optimal allocation of temperature prior to the rolling process. The reason: Constant temperature is essential for the uniformity of the wall thickness of a pipe. The benefit: Consistent wall thickness and concentric inside and outside diameters. The advantage for the user: Even distribution of operational stresses and uniform mechanical properties. For optimum materials quality and to meet the surface and geometric specifications as well as mechanical properties, on-line through process simulation is beneficial in order to optimize both processes and resulting microstructure. For this, proper thermo-mechanical production of seamless pipes will be necessary. This includes the modelling of hardening and softening during forming in the austenitic regime, precipitation kinetics and phase transformation during cooling. The resulting microstructure will help for the calculation of mechanical properties. Specific processes will be identified for influencing strongly the pipe quality and shall be optimized by inverse modeling techniques.