Effect of Accelerated Cooling after Controlled Rolling on the Structure and Properties of Steel 05Г1МБ

摘要

Controlled rolling with accelerated cooling (CR + AC) allows production of high-strength rolled metal with a fine-grain ferrite-bainite structure. The main advantages of accelerating cooling of metal are the following: a possibility to control transition from low-temperature controlled rolling (LTCR) to high-temperature controlled rolling (HTCR), which considerably decreases mill loads during rolling; formation a uniform fine-grain structure with lower degrees of anisotropy of its properties; a possibility to decrease contents of alloying elements at a given strength level of the steel and to enhance its weldability. The accelerating cooling technology is based on controlling processes of the austenite transformation after finishing deformation by changing temperatures of the start (T_(s.c.)) and interruption of accelerating cooling (T_(f.c.)) and also by changing rate of accelerated cooling (v) [1]. The type of structural components and their ratio depend on the combined effect of these parameters.