Control of surface layer for pickle-free hot-rolled strip

The conventional acid pickling operation is one of the most critical steps in the production of steels as the final quality of steel surfaces depends on pickling performance and as environmental pollution is generated during conventional pickling operations. This 3 years project deals with the suppression of acid pickling by two main actions: the production of thin scales in the hot strip mill by a better control of the oxidizing conditions and of adherent scales by a control of their structure and mechanical properties at each step of the processing line - the replacement of acid pickling by gas reduction which will be favored by small thickness (to be done) The research work by the various partners may be divided into the 3 following work packages: - limitation of the scale growth during rolling, on the run out table and during coiling at the hot strip mill. - production of a scale that can withstand all the efforts during rolling in order to form a crack free oxide layer and control the cooling and coiling operation to form an adherent scale layer evaluate the feasibility of scale reduction by gas.