Papers by Keyword: Wire Rod Rolling

Abstract: A wire rod block at Fagersta Stainless AB, Sweden, consists of eight pairs of rolls with consecutive round-oval-round grooves. Test bars of an austenitic stainless steel of type AISI 304L that had been preheated to 930±70°C were manually fed into the wire block. By entering a guide after one of the roll pair, the bar was led out from the block into a water-filled tube for rapid quenching. The guide was moved successively from the first to the last pair of rolls and test bars were collected after each roll pair. In order to characterize the original structure one bar was preheated and directly water quenched without rolling. The aim of this study was to characterize the microstructure evolution during the wire rod rolling using electron backscatter diffraction. The size evolution for all grains, the recrystallized grains and for the subgrains in the deformed grains has been estimated and the fraction of recrystallized grains has been determined. During the first 3 passes almost no recrystallization is observed and strain accumulates. Partial recrystallization then occurs and for the last 3 passes the recrystallization is almost complete and the texture is nearly random.

Abstract: During the last 60 years, tremendous developments have been in wire rod rolling. Finish rolling speeds in the order of 100 – 140 m/s are common and on line wire rod cooling practices, has made it possible to treat the wire rod directly in line in the mill instead of separate off line operations. New procedures for roll setting have been developed to cut the downtime in the mill, by presetting the stands in separate workshops an supply the entire rolling line with fast changing equipment. Much of the efforts have been directed to improve the productivity and the wire rod quality, but also to improve the working environment. In the 21:st century, the main challenge will be the global energy saving and environment protection, which in turn will require new trends in wire rod rolling and wire rod rolling research. The in line treatment will be applied for more steel grades, but the important savings must be solved at the interface between the steelmaking/continuous casting and the wire rod rolling. Hot charging as well as warm rolling will be employed in order to save energy. Their knowledge of the rolling processes will be improved by means of new methods for plastic analysis. New processes must be introduced, where the requirements from the rolling mills will direct the development. These are including casting of smaller billet sections, in order to minimize the mechanical work, and thus the consumption of electrical energy for conversion of the billets to wire rod. By the development of these technologies not only energy will be saved. Better wire rod surfaces can be obtained and the investment cost for new rolling mills will decrease. However the development of new knowledge and new processes requires funding on a level that is hard to expect, especially from the funding system which exists at present.