Ultra Fine Grained Steels Ultra Fine Grained Steels discusses results of the New Generation Iron and Steel Materials research project funded over the last ten years. Modern sustainability requirements want that iron and steel must meet four conditions: stronger longer service life leading edge manufacturing technology (low cost material and energy efficient) and environmentally sound (waste recycling reduced carbon dioxide emission). Therefore new generation iron and steel materials featuring double strength and double service life are needed (labeled ultra steels in Japan). Professor Weng (PhD Materials Science and Engineering Pennsylvania State University) has been engaged in the research of new generation structural materials for the last twelve years being Chief Scientist of three consecutive national research programs in China. This book discusses results of the New Generation Iron and Steel Materials research project funded over the last ten years. It thoroughly describes theoretical achievements in ultra fine grain steel and its refinement. It also discusses progress in related areas of engineering and technology. The author has been engaged in the research of new generation structural materials for the last twelve years being Chief Scientist of three national research programs in China.