Adhesion tests at high temperatures on low-carbon steel scale : rolling-long products and reheating furnaces: final report

Descaling is a major factor in the manufacturing of high-quality hot strip bands and is closely related to the adhesive properties of the scales formed in the reheating furnace. The detrimental effect of alloying (or residual) elements such as silicon, copper, and nickel is well documented. There is, however, no experimental device available to quantify their influence on scale adhesion, and consequently, on descaling. The experimental devices developed up to now can measure adhesive properties at room temperature, but extrapolation at high temperature is somewhat questionable. High temperature measurements do not have the required accuracy and reliability. The objective of the research is to develop a high temperature mechanical test in order to quantify scale adhesion at temperatures of primary or secondary descaling (1 200 °C or 1 000 °C). The main steps of the project included: determination of the oxidation mechanisms, fine characterization of scale and subscale microstructures; designing of a high temperature adhesion test by improving two existing mechanical tests (the deflexion test and the four-point bending test).