S. M. Hwang

An integrated FE process model for precision analysis of thermo-mechanical behaviors of rolls and strip in hot strip rolling

Abstract A finite element (FE)-based approach is presented for the precision analysis of the thermo-mechanical behavior of the rolls and strip in hot strip rolling. Basic FE models for the analysis of the thermal behavior as well as those for the analysis of the mechanical behavior of each object––roll or strip, are described in detail. Also described are various numerical schemes, including those for the treatment of the thermal as well as mechanical interactions among the objects. A series of numerical tests are conducted to assess the validity of the basic FE models and also of the numerical schemes proposed. Then, illustrated is how to combine the basic FE models into an integrated process model for the precision analysis of the thermo-mechanical behavior.

Prediction of Temperature, Sliding Velocity Gradient and Pressure of Roll Groove in Hot Rod Rolling by Finite Element Method

A three‐dimensional and integrated, Eulerian finite element based model is presented for the prediction of temperature, sliding velocity gradient and pressure of roll groove in the hot rod rolling. The model is comprised of basic finite element models, which are incorporated into an iterative solution procedure to deal with interdependence between the thermo‐mechanical behavior of the workpiece and that of the roll. The capability of the model to reveal detailed aspects of the complex interaction between the workpiece and the roll groove is demonstrated through a series of process simulations.

A New Free Surface Prediction Technique For Finite Element Simulation Of Shape Rolling

A new, steady‐state process model is presented for the prediction of the deformation of the workpiece in shape rolling. Described are a three‐dimensional finite element model for the analysis of plastic deformation, a new streamline tracing scheme, and the schemes for free surface convergence, including those for free surface prediction and correction. The process model is then applied to multi‐pass rolling of a variety of commercial parts, to demonstrate the capability to deal with rolling of a complex‐shaped part. Also investigated is the model’s prediction accuracy, through comparison with the measurement.

Analysis of Strip Profile in Flat Rolling by the Finite Element Method

A full, finite element (FE)‐based approach is presented for the precision analysis of the strip profile in flat rolling. Basic FE models for the analysis of the mechanical behavior of the strip and of the rolls are described in detail. Also described is an iterative strategy for a rigorous treatment of the mechanical contact occurring at the roll‐strip interface and at the roll‐roll interface. Then, presented is an integrated FE process model for the coupled analysis of the mechanical behavior of the strip, work roll, and backup roll in four‐high mill. A series of process simulation are conducted and the results are compared with the measurements made in hot and cold rolling experiments.

AUTOMATION OF OVERHEAD MAGNET CRANE SYSTEM IN THICK STEEL PLATE STORAGE YARD

Abstract This paper presents an automation scheme of an overhead magnet crane that is used as an essential part of storage yard automation. First, load cells are introduced to detect the number of lifted steel plates. Then a current control algorithm to lift the right number of steel plates is proposed and implemented by using the on-line tuning look-up table. Finally, the overall hardware and software description for automatic crane operation is presented. The results have been successfully implemented on POSCOs No.2 thick steel plate storage yard.