Abstract: The invention provides a method of fabricating “TRIP” steel in the form of thin strip, wherein: a strip from 1.5 to 10 mm thick, preferably from 1 to 5 mm thick, is cast directly from liquid steel having the composition (in weight percent) C % from 0.05 to 0.25, (Mn+Cu+Ni) % from 0.5 to 3, (Si+Al) % from 0.1 to 4, (P+Sn+As+Sb) % not greater than 0.1, (Ti+Nb+V+Zr+rare earths) % less than 0.3, Cr % less than 1, Mo % less than 1, V % less than 1, the remainder being iron and manufacturing impurities; said strip is hot rolled on-line in one or more passes at a temperature higher than the Ar3 temperature of said steel and with a reduction ratio from 25 to 70%; first forced cooling of said strip is carried out at a cooling rate from 5 to 100° C./s; the strip remains at temperatures from 550 to 400° C.

Abstract: The subject for the invention is a process for manufacturing strip. The process includes casting directly from liquid metal a steel strip 1.5 to 10 mm in thickness, subjecting the cast steel strip, in the austenitic phase, to a first hot rolling operation in one or more steps at a temperature of between 950° C. and the Ar3 temperature of said strip with an overall reduction ratio of at least 10%, then subjecting the hot rolled strip, in the ferritic phase, to a second hot rolling operation in one or more steps at a temperature below 850° C., with an overall reduction ratio of at least 50% in the presence of a lubricant, so as to obtain a hot-rolled sheet with a thickness of less than or equal to 2 mm, and recrystallizing the hot rolled sheet at a temperature between 700 and 800° C. The composition of the steel strip comprises (in weight %): carbon less than 0.1%, manganese from 0.03 to 2%, silicon from 0 to 0.5%, phosphorus from 0 to 0.1%, boron from 0 to 0.002%, titanium from 0 to 0.