The production of ferritically hot rolled interstitial-free steel on a modern hot strip mill

Ferritic hot rolling was developed in the late 1980s through a desire to eliminate temperature control problems when rolling thin hot strip in the austenitic condition. This was accomplished by reducing the finishing temperature to allow rolling to take place with a wholly ferritic microstructure. It was soon discovered, however, that time and cost savings could be realised through this new rolling practice. Laboratory hot rolling facilities and procedures were developed to simulate the ferritic hot rolling process, evaluating variables such as reheating, finishing, coiling temperature, lubrication and hot rolling loads. This allowed the determination of microstructure/mechanical property relationships for interstitial free (IF) grades and the suggestion of suitable processing schedules for both recrystallised and strained ferritically hot rolled material. This evaluation includes the feasibility of manufacturing in the identified hot band products on a modern integrated steel plant.