Download or read book Gaseous Environment Fatigue Crack Propagation Behavior of a Low Alloy Steel written by JK. Donald and published by . This book was released on 1989 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth behavior of 4340 steel was investigated in gaseous environments: laboratory air, hydrogen, and helium. No significant effect of specimen orientation on the rates of fatigue crack propagation was observed. In each environment, increasing load ratio decreased the threshold stress-intensity range (?Kth). The effect of load ratio on ?Kth in the air environment was, however, much more significant than that in wet hydrogen and dry environments (dry hydrogen and dry helium). At low load ratios (? 0.5), the values of ?Kth in the air environment were larger than those in dry environments. The ?Kth values in wet hydrogen were in between those in air and dry environments. At a high load ratio of 0.8, ?Kth was, however, insensitive to test environment.
Download or read book Influences of Gaseous Environment on Low Growth rate Fatigue Crack Propagation in Steels Annual Report No 1 January 1980 Report No FPL R 80 1030 written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of gaseous environment is examined on fatigue crack propagation behavior in steels. Specifically, a fully martensitic 300-M ultrahigh strength steel and a fully bainitic 2-1/4Cr-1Mo lower strength steel are investigated in environments of ambient temperature moist air and low pressure dehumidified hydrogen and argon gases over a wide range of growth rates from 10−8 to 10−2 mm/cycle, with particular emphasis given to behavior near the crack propagation threshold .delta.K0. It is found that two distinct growth rate regimes exist where hydrogen can markedly accelerate crack propagation rates compared to air, (1) at near-threshold levels below (5 x 10−6 mm/cycle) and (2) at higher growth rates, typically around 10−5 mm/cycle above a critical maximum stress intensity K/sub max//sup T/. Hydrogen-assisted crack propagation at higher growth rates is attributed to a hydrogen embrittlement mechanism, with K/sub max//sup T/ nominally equal to K/sub Iscc/ (the sustained load stress corrosion threshold) in high strength steels, and far below K/sub Iscc/ in the strain-rate sensitive lower strength steels. Hydrogen-assisted crack propagation at near-threshold levels is attributed to a new mechanism involving fretting-oxide-induced crack closure generated in moist (or oxygenated) environments. The absence of hydrogen embrittlement mechanisms at near-threshold levels is supported by tests showing that .delta.K0 values in dry gaseous argon are similar to .delta.K0 values in hydrogen. The potential ramifications of these results are examined in detail.
Download or read book Fracture Mechanics written by and published by ASTM International. This book was released on 1989 with total page 685 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue crack propagation of low alloy steel in a vacuum environment final report written by L. A. James and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Propagation of Low alloy Steel in a Vacuum Environment written by Electric Power Research Institute and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temperature and Environmentally Assisted Cracking in Low Alloy Steel written by T. A. Auten and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Corrosion Fatigue Crack Propagation Behaviour of a High Strength Low Alloy Steel in a Synthetic Sea Water Environment written by P. G. Millar and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Aqueous Environments Upon the Initiation and Propagation of Fatigue Cracks in Low alloy Steels written by and published by . This book was released on 1996 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of elevated temperature aqueous environments upon the initiation and propagation of fatigue cracks in low-alloy steels is discussed in terms of the several parameters which influence such behavior. These parameters include water chemistry, impurities within the steels themselves, as well as factors such as the water flow rate, loading waveform and loading rates. Some of these parameters have similar effects upon both crack initiation and propagation, while others exhibit different effects in the two stages of cracking. In the case of environmentally-assisted crack (EAC) growth, the most important impurities within the steel are metallurgical sulfide inclusions which dissolve upon contact with the water. A ''critical'' concentration of sulfide ions at the crack tip can then induce environmentally-assisted cracking which proceeds at significantly increased crack growth rates over those observed in air. The occurrence, or non-occurrence, of EAC is governed by the mass-transport of sulfide ions to and from the crack-tip region, and the mass-transport is discussed in terms of diffusion, ion migration, and convection induced within the crack enclave. Examples are given of convective mass-transport within the crack enclave resulting from external free stream flow. The initiation of fatigue cracks in elevated temperature aqueous environments, as measured by the S-N fatigue lifetimes, is also strongly influenced by the parameters identified above. The influence of sulfide inclusions does not appear to be as strong on the crack initiation process as it is on crack propagation. The oxygen content of the environment appears to be the dominant factor, although loading frequency (strain rate) and temperature are also important factors.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Initiation and Propagation in Steels Exposed to Inert and Corrosive Environments written by Kourosh Youssefi and published by . This book was released on 1978 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Propagation Behavior of 21 4Cr 1Mo Steels for Thick Wall Pressure Vessels written by RO. Ritchie and published by . This book was released on 1982 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack propagation behavior of a series of thick-section [20.3 cm (8 in.)] 21⁄4Cr-1Mo steels has been investigated in environments of gaseous hydrogen and ambient temperature air over a wide range of growth rates from near-threshold levels (10-11 m/cycle) to 10-4 m/cycle, as part of a program to characterize potential materials for coal gasification pressure vessel applications. Normalized bainitic-ferritic microstructures (ASTM A 387, Class 2, Grade 22) have been compared with quenched and tempered fully bainitic (ASTM A 542, Class 3) and fully martensitic (ASTM A 542, Class 2) microstructures, representing a range of yield strengths from 290 to 769 MPa. Although growth rates above 10-9 m/cycle are largely unaffected by microstructure and strength level, at near-threshold growth rates there is a marked deterioration in crack propagation resistance with increasing strength which becomes accentuated for tests in hydrogen environments. Further, the influence of gaseous hydrogen on fatigue crack propagation rates is found to be particularly severe at stress intensities far below KIscc, the threshold for hydrogen-assisted growth under sustained loading. At near-threshold levels ("true corrosion fatigue" regime) the presence of hydrogen gas enhances growth rates by up to two orders of magnitude compared with air, without a significant change in fracture mechanism. At higher growth rates ("apparent stress-corrosion fatigue" regime), a second acceleration in growth rates (up to 20 times compared with air) due to hydrogen is observed above a critical Kmax-value, which is both sensitive to frequency and load ratio and is associated with a predominately intergranular fracture mode. The characteristics of these distinct regimes of hydrogen-assisted fatigue crack propagation in 21⁄4Cr-1Mo steels are discussed in the light of the potential use of these steels for coal conversion pressure vessel construction.
Download or read book Fatigue environmental Crack Propagation in a High Strength Steel written by Thomas Charles Babcock and published by . This book was released on 1969 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gaseous Hydrogen Embrittlement of Materials in Energy Technologies written by Richard P Gangloff and published by Elsevier. This book was released on 2012-01-16 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many modern energy systems are reliant on the production, transportation, storage, and use of gaseous hydrogen. The safety, durability, performance and economic operation of these systems is challenged by operating-cycle dependent degradation by hydrogen of otherwise high performance materials. This important two-volume work provides a comprehensive and authoritative overview of the latest research into managing hydrogen embrittlement in energy technologies.Volume 1 is divided into three parts, the first of which provides an overview of the hydrogen embrittlement problem in specific technologies including petrochemical refining, automotive hydrogen tanks, nuclear waste disposal and power systems, and H2 storage and distribution facilities. Part two then examines modern methods of characterization and analysis of hydrogen damage and part three focuses on the hydrogen degradation of various alloy classesWith its distinguished editors and international team of expert contributors, Volume 1 of Gaseous hydrogen embrittlement of materials in energy technologies is an invaluable reference tool for engineers, designers, materials scientists, and solid mechanicians working with safety-critical components fabricated from high performance materials required to operate in severe environments based on hydrogen. Impacted technologies include aerospace, petrochemical refining, gas transmission, power generation and transportation. Summarises the wealth of recent research on understanding and dealing with the safety, durability, performance and economic operation of using gaseous hydrogen at high pressure Reviews how hydrogen embrittlement affects particular sectors such as the petrochemicals, automotive and nuclear industries Discusses how hydrogen embrittlement can be characterised and its effects on particular alloy classes
Download or read book Hydrogen Gas Embrittlement written by Hisao Matsunaga and published by Elsevier. This book was released on 2024-01-22 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen Gas Embrittlement: Mechanisms, Mechanics, and Design enables readers to understand complicated hydrogen-material interactions and conduct better material selection and strength design for hydrogen components. The book reviews the fundamental mechanisms of hydrogen embrittlement, the various behaviors of hydrogen in metallic materials such as diffusion, solution, and trapping, and emphasizes the necessary properties for effective strength design of various materials under the influence of hydrogen, including tensile properties, fatigue life, fatigue limit, fatigue crack-growth, and fracture toughness. Sections provide experimental data obtained in hydrogen gas at various pressures and temperatures together with the fractographic observations, including practical interpretation of hydrogen compatibility of materials based on tensile, fatigue and fracture mechanics testing results. Material testing machines and methods, the effects of hydrogen on various BCC steels, austenitic steels, and non-ferrous metals, and practical applications and methods of strength design for hydrogen vessels and components are all included as well. Enables a better understanding of hydrogen-material interactions, allowing for better material selection and strength design Provides insights on the hydrogen-induced degradation of materials strength at the atomic, macroscale and microscale Looks at a number of degradative behaviors in a variety of materials, including BCC steels, austenitic steels and non-ferrous metals Includes verification tests, case studies, applications and experimental data
Download or read book LaQue s Handbook of Marine Corrosion written by David A. Shifler and published by John Wiley & Sons. This book was released on 2022-07-13 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new edition of LaQue's classic text on marine corrosion, providing fully updated control engineering practices and applications Extensively updated throughout, the second edition of La Que's Handbook of Marine Corrosion remains the standard single-source reference on the unique nature of seawater as a corrosive environment. Designed to help readers reduce operational and life cycle costs for materials in marine environments, this authoritative resource provides clear guidance on design, materials selection, and implementation of corrosion control engineering practices for materials in atmospheric, immersion, or wetted marine environments. Completely rewritten for the 21st century, this new edition reflects current environmental regulations, best practices, materials, and processes, with special emphasis placed on the engineering, behavior, and practical applications of materials. Divided into three parts, the book first explains the fundamentals of corrosion in marine environments, including atmospheric corrosion, erosion, microbiological corrosion, fatigue, environmental cracking, and cathodic delamination. The second part discusses corrosion control methods and materials selection that can mitigate or eliminate corrosion in different marine environments. The third section provides the reader with specific applications of corrosion engineering to structures, systems, or components that exist in marine environments. This much-needed new edition: Presents a comprehensive and up-to-date account of the science and engineering aspects of marine corrosion Focuses on engineering aspects, descriptive behavior, and practical applications of materials usage in marine environments Addresses the various materials used in marine environments, including metals, polymers, alloys, coatings, and composites Incorporates current regulations, standards, and recommended practices of numerous organizations such as ASTM International, the US Navy, the American Bureau of Shipping, the International Organization for Standardization, and the International Maritime Organization Written in a clear and understandable style, La Que's Handbook of Marine Corrosion, Second Edition is an indispensable resource for engineers and materials scientists in disciplines spanning the naval, maritime, commercial, shipping industries, particularly corrosion engineers, ship designers, naval architects, marine engineers, oceanographers, and other professionals involved with products that operate in marine environments.
