IMPROVEMENT OF STRIP PRODUCTION TECHNOLOGY IN CONTINUOUS CASTING AND ROLLING MODULES

Abstract

The article presents materials where CRM and HSM technologies are compared. The strip production technology in CRM is more progressive but both complexes have some limitations. CRM has less metal consumption at the expense of lower metal waste when combining casting and rolling continuous processes. Gas consumption is also lower and depends on slabs thicknesses and their initial temperature. The other consumptions relationship between CRMs and HSMs can be changed depending on the specific product mix production. But CRMs have some limits in low stain rate during the roughing rolling process. On the other hand, the flexibility of HSMs complexes is more because they are not directly connected with continuous casting machine and Meltshop. Similar steel grades can be produced at any of these two complexes, but thicknesses in each steel group differ. For rolling product production by TMCP it is very important, for achieving the final mechanical properties, to adhere to all temperature and reduction principes. The austenite grain diameter managing and metal structure at both complexes have differences. The reduction and strain rate have joint significant influence on the austenite grain size. The article has identified, for obtaining austenite finer grain, the strain rate must be 1.0 c−1 or more, deformation is to be 20 % or more. The optimized rolling schedule for strip dimensions 12 × 2074 mm, steel grade X70 at the CRM has been offered in the article. The optimized rolling schedule has satisfied all TMCP conditions such as temperature, reduction and strain rate to ensure a mechanical properties complex.