Microtexture of thin gauge hot rolled steel strip

Abstract

A series of trials were conducted on a compact rolling mill to evaluate the properties and characteristics of carbon steel strip hot rolled to less than 2 mm in thickness from thin cast slabs. Steels of two different compositions were studied, the first one, a low carbon steel, was rolled to a total reduction ranging from 94 to 98%, final thickness ranging from 1.06 to 2.69mm, whereas the second one was a Nb bearing microalloyed steel rolled to a total reduction of around 96%. The rolling trials were complemented by means of computer modelling to get a deeper understanding of the process. It was found that the ferritic grain size of the low carbon strips varied from 7 to 10 μm, with the finer sizes found in the thinner strips, the grain size of the microalloyed steel was found to be 3.6μm. Analysis of the texture of the hot rolled strips indicated that the ferrite in the low carbon resulted from the transformation of recrystallized austenite, in comparison, low intensity transformation texture from unrecrystallized austenite was found in the Nb bearing steel. The observed texture data correlate with the R-values measured.