Microstructural And Strain Rate Effects On Stage Iii Strain Hardening And Ductility In Dual Phase Steels

Dual-phase steels exhibit good mechanical properties due to a microstructure of strong martensitic inclusions embedded in a ductile ferritic matrix. This work presents a two-scale model for the underlying work-hardening effects; such as the distinctly different hardening rates observed for high-strength dual-phase steels. The model is based on geometrically necessary dislocations and comprises the average microstructural morphology as well as a direct interaction between the constituents.

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.

Microstructure and Texture in Steels and Other Materials comprises a collection of articles pertaining to experimental and theoretical aspects of the evolution of crystallographic texture and microstructure during processing of steels and some other materials. Among the topics covered is the processing-microstructure-texture-property relationship in various kinds of steels, including the latest grade. Special emphasis has been given to introduce recent advances in the characterization of texture and microstructure, as well as modeling. The papers included are written by well-known experts from academia and industrial R and D, which will provide the reader with state-of-the-art, in-depth knowledge of the subject. With these attributes, Microstructure and Texture in Steels and Other Materials is expected to serve the cause of creating awareness of current developments in microstructural science and materials engineering among academic and R and D personnel working in the field.

Dual-phase steels exhibit good mechanical properties due to a microstructure of strong martensitic inclusions embedded in a ductile ferritic matrix. This work presents a two-scale model for the underlying work-hardening effects; such as the distinctly different hardening rates observed for high-strength dual-phase steels. The model is based on geometrically necessary dislocations and comprises the average microstructural morphology as well as a direct interaction between the constituents. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thougtit that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 31 (thesis year 1986) a total of 11 ,480 theses titles trom 24 Canadian and 182 United States universities. We are sure that this broader base tor these titles reported will greatly enhance the value ot this important annual reterence work. While Volume 31 reports theses submitted in 1986, on occasion, certain univer sities do re port theses submitted in previousyears but not reported at the time.

A recently implemented fracture control plan for structural steel high-way bridges makes use of a linear relation to describe the effect of strain rate on the ductile/brittle transition temperature as a function of yield strength. Literature data show that the predictions of the aforementioned relation are not general. An alternative analysis is offered along with a qualitative model for understanding the phenomenon. Results of an experimental program investigating microstructural effects on the ductile/brittle strain rate dependence are also presented. The results exhibit linear behavior of ?Tdb versus ??/?, where ?Tdb is the transition temperature shift, ? is the yield stress, and ?? is the change in yield stress caused by strain rate. The magnitude of the temperature shift, however, is dependent upon the test specimen used. Factors discussed include microstructure, type of test specimen (Charpy V-notch, nil ductility temperature [NDT], modified NDT, or compact toughness), crack initiation versus crack propagation, and implications for regulatory bodies.