Temperature and Structure Numerical Analysis in the Overlaying of a Bimetallic Roll

摘要

A model was created describing the field of temperatures and distribution of the phase and structural composition in a bimetallic casting roller throughout the built-in welding process. The non-linear and non-static problem of thermal conductivity is solved using a method based on finite elements. Limit conditions of the third kind are used to describe the conditions of thermal conductivity. Heat emitted at phase and structural transitions is taken into account. It was assumed that heat physics coefficients depend on the temperature and structure. Liquid-to-solid transition was modelled using linear approximation. Avrami equation was used to describe the kinetics of austenite-to-perlite transition. The transition between the isothermal kinetics of the austenite degradation to the non-isothermal conditions was calculated using the theory of isokinetic reaction, using the additivity rule. The results for the calculation of temperatures and structures throughout the build-up welding process are presented. The software developed in the course of this research can be used for numeric modelling of the strained and deformed casting roller during the build-up welding.