Thermal-Mechanical Modelling of the Flat Rolling Process

ISBN-13: 9783642843273 / Angielski / Miękka / 2011 / 202 str.

Maciej Pietrzyk; John G. Lenard

Opis

Flat rolling is considered to be one of the most important and most widely used metal forming processes. This book emphasizes the importance of mathematical simulation of this process in the light of the ever in- creasing need for quality improvements through automation. Mathematical models of the hot, warm and cold rolling processes are discussed, compared and critically evaluated. Engineers in the steel industry will find this book particularly useful in their everyday work.

Spis treści

1 Introduction.- 2 Material Properties and Interfacial Friction.- 2.1 Resistance to Deformation.- 2.1.1 Empirical Constitutive Relations for Carbon Steels.- 2.1.2 High Strength Low Alloy Steels.- 2.1.3 Representation of the Results of Compression Tests.- 2.2 Friction in the Flat Rolling Process.- 2.2.1 Friction as a Function of Process and Material Parameters.- 2.2.2 Interfacial Forces in the Roll Gap During Flat Rolling.- 2.2.3 Discussion.- 3 One-Dimensional Models of Flat Rolling.- 3.1 Conventional Models.- 3.1.1 Orowan’s Theory.- 3.1.2 Sims’ Method.- 3.1.3 Bland and Ford’s Technique.- 3.1.4 Ford and Alexander’s Method.- 3.1.5 Tselikov’s Solution.- 3.2 Refinement of the Conventional Models.- 3.2.1 Derivation of the Basic Equations.- 3.2.2 Roll Deformation.- 3.2.3 Roll Force and Roll Torque.- 3.3 Comparison of Mathematical Models of Flat Rolling.- 3.3.1 Comparison of Assumptions in Various Models.- 3.3.2 Statistical Analysis of Predictive Capabilities.- 3.4 Further Substantiation of the Predictive Capabilities of One- Dimensional Models.- 4 Thermal-Mechanical Finite-Element Modelling of Flat Rolling.- 4.1 Rigid-Plastic Finite-Element Method.- 4.1.1 Description of the Method.- 4.1.2 Boundary Conditions.- 4.1.3 Structure of the Computer Program.- 4.2 Heat Transfer.- 4.2.1 Numerical Solution of the Fourier Equation.- 4.2.2 Steady State Model With Convection.- 4.3 Results of Computations.- 4.3.1 Hot Rolling.- 4.3.2 Cold Rolling.- 4.4 Experimental Substantiation of the Model’s Predictions.- 4.4.1 Hot Rolling of Steel.- 4.4.2 Warm Rolling of Aluminium.- 4.4.3 Cold Rolling of Aluminium.- 4.5. Role of the Heat Transfer Coefficient.- 5 The Role of the Shape Coefficient in Modelling of the Flat Rolling Process.- 5.1 Correlation between the Shape Coefficient and Load Parameters.- 5.1.1 The Effect of ? on the Friction Stresses.- 5.1.2 The Effect of ? on Forces and Torques.- 5.2 The Effect of the Shape Coefficient on Strain and Strain Rate Distributions.- 5.2.1 Finite-Element Analysis of Strain Rate Fields for Various Shape Coefficients.- 5.2.2 Efficiency of the Rolling Process.- 6 Conclusions.- References.- Author Index.

O autorze

Thermal-mechanical modelling of hot, warm and cold rolling is presented. The dependence of the accuracy and consistency of the predictions on the boundary conditions - heat transfer and friction - and on the initial conditions - The resistance of the material to deformation - is discussed.