Thermo-metallurgical model for hot rolled strip,

G. GOMEZ; J. SCHICHT; M.A. VICENTE ALVAREZ; F. BALZAROTTI; T. PEREZ; M. GOLDSCHMIT; J. MORICONI

Pittsbourgh USA

Congreso; MS&T 2008; 2008

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-update:auto; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> A coupled thermo-metallurgical model was developed to predict the mechanical properties of hot rolled steel strips all along the coil length. The thermal finite element (FE) model solves the heat diffusion equation considering the transformation enthalpy produced by the austenite decomposition. In the run out table, the thermal model evaluates the temperature evolution considering the heat extraction due to the water sprays. After coiling, the model solves the thermal evolution in the cylindrical geometry. The metallurgical model calculates the kinetic of austenite decomposition and evaluates the transformation enthalpy. It also predicts the grain size, pearlite laminar spacing and precipitation of elements in solid solution. The predictions of the coupled model were compared with temperature measurements at the end of the run out table (coiling temperature) for C-Mn and microalloyed steels with excellent agreement. Moreover the predicted yield strength and ultimate tensile strength had a good agreement with measurements performed on more than 130 plant processed coils.