Due to the comprehensive correlation among steel industry itself and up and down stream¡Aand it often be compared as the national power index and is also the strategic fundamental industry of a country .Besides it can change a whole industial structure and economy of a country. So no matter modern and develop- ing countries all pay a great attention in steel industry. After the rise of the giant¡XChina,it had had a great influence on world economy,at the same time it also led the globe steel industry to another golden age.But just because the wake of China,it had also had a great impact on world steel industry,in addition to the global industry itself had suffered a decade¡¦s depression led to the structural change. In Europe and America area,steel companies prefer using accquisition ,whereas asia companies prefer using strategic alliance. Besides,Taiwan steel industry had suffered some invisible crisis due to the wake of China ,the movement of the downstream industry, and the insufficient of upstream crude steel. Moreover,the No.1 steel industry of Taiwan,CSC(China Steel Company),also had suffered some decline on the major international competitence. So this thesis had already reviewed large amount of articeles,news,reports and concluded ten future trends of global steel industry.Using this ten trends to check the recent actions from CSC to see if it matched the future trends or not.Finally,this thesis use these ten trends to give some strategic advices for CSC company.

Quantitative relationships among processing parameters, microstructure, and material properties are of considerable interest in the context of development of robust processing routes that optimize the required material properties. As a result, the scientific literature contains a large number of experimental and theoretical studies on microstructure-properties relationships. Fracture sensitive mechanical properties such as ductility, ultimate tensile strength, fatigue life, and fracture toughness depend on the average microstructural parameters as well as the distributions of microstructural parameters and their extrema.Development of quantitative relationships between such material properties and microstructural distributions and extrema has received considerably less attention, particularly in the wrought metals and alloys. Accordingly, an important objective of this research is to perform a systematic investigation in this direction. The dependence of the fracture-sensitive mechanical properties on the microstructural distributions and extrema often leads to substantial variability in these properties: a set of specimens having the same average chemistry, the same average processing history, and the same average microstructural parameters such as volume fractions of different constituents can exhibit substantially different material properties. The present research (i) is concerned with high strength (~ 1000 MPa) high martensite (>50%) dual phase steel where the martensite is a topologically continuous phase (matrix) containing a dispersion of islands of ferrite, and (ii) focuses on understanding the microstructural origins of the variability in fracture sensitive mechanical properties, in particular variability in the room temperature uniaxial tensile ductility. The research involves quantitative microstructure characterization using stereology and digital image processing and quantitative fractography using scanning electron microscopy (SEM) and fracture profilometry. The analysis of the quantitative fractographic and microstructural data obtained in this research leads to useful guidelines for reducing the variability in the tensile ductility of the dual phase steel under investigation.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 361-370). Available also in a digital version from Dissertation Abstracts.

Thesis(M.S.)--Case Western Reserve University, 2009 / Title from PDF (viewed on 2010-01-28) Department of Materials Science and Engineering Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center

Thesis (Ph. D.)--Lehigh University, 2002. / Includes vita. Includes bibliographical references (leaves 143-159).

Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 146-172).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains ix, 56 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 51-52).

Thesis--M.A., University of Hong Kong. / Typewritten.

Thesis--M. Sc.(Eng.), University of Hong Kong. / Typewritten.

Growing economical and ecological requirements have driven the automotive industry towards lowering fuel consumption by reducing vehicle weight and in the meantime maintaining safety standards. This pushes the development of advanced light weight alloys. As a promising candidate for automotive applications, the twinning induced plasticity (TWIP) steels have received tremendous attention due to their superior mechanical properties, which combines high ultimate tensile strength and ductility simultaneously. However, their plasticity mechanism and recovery behavior are still not completely understood. In the first part of this investigation, a modified physical-based model is developed based on the recent observations of strong influence of grain orientation and Bauschinger effect. The model describes well the serrated plastic flow of Fe-22Mn-0.6C TWIP steel under quasi-static tensile loading at ambient temperature. The discrete twinning is considered responsible for the serration phenomenon in Fe-22Mn-0.6C TWIP steel. The model also provides a new approach to estimate the volume fraction of deformation twins. In the second part of this investigation, the recovery of pre-strained Fe-22Mn-0.6C TWIP steel is studied. A model describes the evolution of yield stress during annealing is proposed, which indicates that the recovery treatment does not remove deformation twins induced by cold rolling but decreases dislocation density in matrix and removes the dislocations piled up against twin and grain boundaries. The recovery activation energy rec Q is derived from experimental results. The value Qrec = 1.73 eV = 167 kJ/mol implies that the diffusion from dislocations cores governs the recovery of investigated TWIP steel. / published_or_final_version / Mechanical Engineering / Master / Master of Philosophy