Author: James Antoni WasynczukPublisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 132
Book Description
The Effects of Microstructure on Fatigue Crack Growth in Duplex Ferrite-martensite Steels
Author: James Antoni WasynczukPublisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 132
Book Description
Energy Research Abstracts
Author: Scientific and Technical Aerospace Reports
Author: ERDA Energy Research Abstracts
Author: Fatigue Crack Initiation and Growth in Dual-phase Steels
Author: Jianku ShangStudy of the Effect of Microstructural Constituents on Fatigue Crack Propagation of High-performance PM Steels
Author: Saba MousavinasabPublisher:
ISBN:
Category :
Languages : en
Pages : 134
Book Description
This research is mostly planned to enhance the fatigue properties of PM steels inasmuch as they are extensively replacing their equivalent wrought steels due mostly to production cost benefits. This goal is going to be achieved through determining the most effective microstructure of PM steels in cyclic loadings. The most effective microstructure is the one that can reduce or stop the fatigue crack propagation through the proper combination of its constituent phases. There exists some researches on this topic, however, they did not reach consistent conclusions due to the lack of sufficient data and/or improper comparison. Therefore, the effect of different constituent phases of a heterogeneous microstructure of a PM steel is still ambiguous and unknown. In order to study this issue, diverse microstructures and the fatigue crack propagation behaviour through them should be studied. Our research begins by choosing two common PM steels manufactured using two alloying techniques of admixed and pre-alloyed to produce heterogeneous and homogeneous microstructures respectively. Two types of heat-treatments namely sinter-hardening and oil-quenching were also utilized to provide more microstructural phases that is needed for the purpose of this study. The samples were then tested in cycling loading using different R-ratio in order to study the effect of fatigue conditions as well. Quantitative analysis of the fracture surfaces, which includes the detailed study of the crack path in OM and SEM, were then performed on the fractured samples. The fatigue crack growth rate data in different PM steels having different microstructures along with the quantitative data acquired from their crack path led us to interesting results on the effect of microstructural constituents on fatigue crack propagation behaviour. It was found that the fatigue crack will propagate more rapidly through the weakest i.e. lowest strength phase among the ones present in the microstructure. Thus, pearlite was not favourable for crack propagation in the company of Ni-rich ferrite while in the presence of martensite, pearlitic grains were found to be the preferred crack path. Moreover, the retained austenite, which was identified in literature to be a beneficial phase for fatigue crack retardation, was found to be ineffective on the matter. Although fatigue cracks circumvented these regions, the deflection caused by this change of crack path did not show any positive effect on fatigue crack retardation.
Applied Mechanics Reviews
Author: Microstructural effects on the fatigue behavior of fe-c-x alloys
Author: Gary J. ShifletGovernment Reports Announcements & Index
Author: Advances in Fatigue Science and Technology
Author: C. Moura BrancoPublisher: Springer Science & Business Media
ISBN: 9400922779
Category : Technology & Engineering
Languages : en
Pages : 982
Book Description
This volume contains the edited version of lectures and selected research contributions presented at the NATO ADVANCED STUDY INSTITUTE on ADVANCES IN FATIGUE SCIENCE AND TECHNOLOGY. held in Alvor. Portugal, 4th to 15th of April 1988. and organized by CEMUL - Center of Mechanics and Materials of The Technical University of Lisbon. The Institute was attended by 101 participants, including 15 lecturers. from 14 countries. The participants were leading scientists and engineers from universities, research institutions and industry. and also Ph.D~ students. Some participants presented papers during the Institute reporting the state-of-art of their research projects. All the sessions wel'e very active and quite extensive discussions on scientific aspects took place during the Institute. The Advanced Study Institute provided a forum for interaction among eminent scientists and engineers. from different schools of thought and young researchers. The Institute addressed the foundations and current state of the art of essential aspects related to fatigue science and technology, namely: Short Cracks, Metallurgical Aspects, Environmental Fatigue, Threshold Behaviour, Notch Behaviour. Creep and Fatigue Interactions at High Temperature, Multiaxial Fatigue, Low Cycle Fatigue, Methodology of Fatigue Testing, Variable Amplitude Fatigue, Fatigue of Advanced Materials. Elastic-Plastic Fatigue, and several engineering applications such as welded joints, energy systems, offshore structures, automotive industry, machine and engine components. This book is organized in three parts: Part I: Fundamentals of Fatigue Part II: Engineering Applications Part III: Research Contributions The research contributions covered most of the areas referred above.