Electrical reheating of slabs

Important results from the project

The purpose of the project is for the steel industry´s slab heating processes to be electrified in an optimal way, i.e. with the right form of electric heating method in terms of geometry, size, material, temperature range, temperature uniformity and energy efficiency. The project has, through pilot tests and simulations, fulfilled the goal of adapting and optimizing a combination of inductive and resistive reheating of slabs prior to hot rolling and presented recommendations to the industry for the best electrical heating methods.

Expected long term effects

The calculation tools for reheating of steel developed in the project can be used for optimization and scaling up of pilot tests, to industrial heating geometries. The knowledge from the project can be used as a basis for decisions on future investments in new heating methods and equipment. Electrification of Swerim´s reheating furnace creates a flexible test and demo at a semi-industrial scale for slabs, blooms and billets, where a combination of inductive and electrical resistive heating technologies was developed and tested within the project and is now available for future tests.

Approach and implementation

A compilation of induction heating´s "State of the Art" was presented. Simulations of inductive heating with material data for current materials were performed. Through the electrification of Swerim´s walking beam furnace, a test and demo facility was developed that meets the companies´ requirements for reliability and validity. Process-related key figures such as energy efficiency, heating rate and total heating time as well as quality measures such as temperature uniformity were evaluated.