Superior Properties of Ultra-fine-grained Steels

Abstract

A description of the improved mechanical properties obtained in ultra-fine-grained steels up to now will be presented in this paper, and some potential applications of these new generation steels will be described. In addition, the principle and implementation of a novel hot rolling process developed by the author will be introduced. This novel Thermomechanical Nonrecrystallisation Control Process (TNCP) has been shown to give an ultra-fine ferrite (uff) structure with grain sizes of 2 to 3mm in various test steels, thus resulting in super-toughness. Charpy V impact test results suggest that some of these steels could still be tough at temperatures lower than -100 °C. This novel process, TNCP, is one potential candidate for the commercial production of superior ultra-fine-grained steels in the future.