Optimization of Tube-Rolling on a 140 Mill

In order to improve the quality, strength, and ductility characteristics of rolled low-alloy steels, it is essential that the rolled product undergo accelerated cooling immediately after it leaves the last finishing stand of the mill. This is done to preserve the structural state produced by hot plastic deformation. The austenite of the metal subsequently decomposes within the same temperature range in which the properties required of the finished product are obtained. This article reports on a study made of the effect of process factors in the accelerated cooling of rolled products of steel 15G2FB on the resulting structure and properties of the steel. The effect obtained from accelerated cooling after high-temperature rolling is determined to a large extent by the possibilities for slowing austenite recrystallization. The rate at which the recrystallization process takes place depends on the chemical composition of the steel, deformation temperature, the extent to which accelerated cooling and self-tempering have been completed, and other factors. These indices determine the structure and properties of the product.