Fatigue And Corrosion In Metals

This textbook, suitable for students, researchers and engineers, gathers the experience of more than 20 years of teaching fracture mechanics, fatigue and corrosion to professional engineers and running experimental tests and verifications to solve practical problems in engineering applications. As such, it is a comprehensive blend of fundamental knowledge and technical tools to address the issues of fatigue and corrosion. The book initiates with a systematic description of fatigue from a phenomenological point of view, since the early signs of submicroscopic damage in few surface grains and continues describing, step by step, how these precursors develop to become mechanically small cracks and, eventually, macrocracks whose growth is governed by fracture mechanics. But fracture mechanics is also introduced to analyze stress corrosion and corrosion assisted fatigue in a rather advanced fashion. The author dedicates a particular attention to corrosion starting with an electrochemical treatment that mechanical engineers with a rather limited knowledge of electrochemistry will well digest without any pain. The electrochemical introduction is considered an essential requirement to the full understanding of corrosion that is essentially an electrochemical process. All stress corrosion aspects are treated, from the generalized film rupture-anodic dissolution process that is the base of any corrosion mechanism to the aggression occurring in either mechanically or thermally sensitized alloys up to the universe of hydrogen embrittlement, which is described in all its possible modes of appearance. Multiaxial fatigue and out-of-phase loading conditions are treated in a rather comprehensive manner together with damage progression and accumulation that are not linear processes. Load spectra are analyzed also in the frequency domain using the Fourier transform in a rather elegant fashion full of applications that are generally not considered at all in fatigue textbooks, yet they deserve a special place and attention. The issue of fatigue cannot be treated without a probabilistic approach unless the designer accepts the shame of one-out-of-two pieces failure. The reader is fully introduced to the most promising and advanced analytical tools that do not require a normal or lognormal distribution of the experimental data, which is the most common case in fatigue. But the probabilistic approach is also used to introduce the fundamental issue of process volume that is the base of any engineering application of fatigue, from the probability of failure to the notch effect, from the metallurgical variability and size effect to the load type effect. Fractography plays a fundamental role in the post mortem analysis of fatigue and corrosion failures since it can unveil the mystery encrypted in any failure.

Corrosion fatigue is fatigue in a corrosive environment. It is the mechanical degradation of a material under the joint action of corrosion and cyclic loading. Nearly all engineering structures experience some form of alternating stress, and are exposed to harmful environments during their service life. The environment plays a significant role in the fatigue of high-strength structural materials like steel, aluminum alloys and titanium alloys. Materials with high specific strength are being developed to meet the requirements of advancing technology. However, their usefulness depends to a large extent on the extent to which they resist corrosion fatigue. The effects of corrosive environments on the fatigue behavior of metals were studied as early as 1930. The phenomenon should not be confused with stress corrosion cracking, where corrosion (such as pitting) leads to the development of brittle cracks, growth and failure. The only requirement for corrosion fatigue is that the sample be under tensile stress.

Fatigue of Metals provides a general account of the failure of metals due to fatigue, a subject of great practical importance in the field of engineering and metallurgy. The book covers a wide range of topics on the study of the fatigue of metals. The text presents in the first three chapters the characteristics and detection of fatigue fractures; methods of fatigue testing; and the fatigue strengths of different materials. The resistance of materials to fatigue under complex stress; the determination and effects of stress concentration; influence of surface treatment on fatigue strength; and effects of corrosion and temperature are also studied in detail. In relation to the previous chapters of fatigue information, a chapter is devoted to engineering design to prevent fatigue. The last two chapters provide a brief historical survey of the developments of the study of the mechanism of fatigue and fatigue of non-metallic materials such as wood, plastic, rubber, glass, and concrete. Mechanical engineers, designers, metallurgists, researchers, and students will find the book as a good reference material.

Metal fatigue is an essential consideration for engineers and researchers who are looking at factors that cause metals to fail through stress, corrosion, etc. This is an English translation of a book originally published in Japan in 1993, with an additional two chapters on the fatigue failure of steels and the effect of surface roughness on fatigue strength. The methodology is based on important and reliable results and may be usefully applied to other fatigue problems not directly treated in this book.

Corrosion due to water is one of the most significant and complex causes of damage to metallic products. Written from the viewpoint of physical chemistry, this authoritative and established text deals with the aqueous corrosion of metals. Available for the first time in English, Corrosion of Metal addressing engineers, metallurgists, physicists and chemists. This self-contained, valuable reference comprehensively organizes and makes readily accessible the accumulated wealth of fundamental and applied knowledge. The concentration is on the underlying essentials of corrosion and failure, and the material is consistently presented in relation to practical applications to corrosion protection. The first chapters introducing the physicochemical principles are ideal for students. The following chapters provide an overview of the state of research for those familiar with the fundamentals. An exhaustive bibliography and appendices conclude the volume.

Definitive, clearly written, and well-illustrated volume addresses all aspects of the subject, from the historical development of understanding metal fatigue to vital concepts of the cyclic stress that causes a crack to grow. Examines effect of stress concentrations on notches, theories of fatigue crack propagation, and many other topics. Seven appendixes describe laboratory fatigue testing, stress concentrations, material stress-strain relationships, and more. Invaluable text for students of engineering design and metallurgy.