Download or read book Crack Initiation in a High Strength Low Alloy Steel written by BL. Braglia and published by . This book was released on 1979 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack initiation behavior of a high-strength low-alloy steel, VAN-80, has been investigated. Crack initiation was defined, for the purposes of the study, as the existence of a 0.25-mm long crack on either surface of a modified compact tension specimen.

Download or read book Crack Initiation in Low Alloy Steel in High Temperature Water written by RE. DeLair and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes a study of fatigue crack initiation in WB36, a German low alloy steel, tested in high temperature, high purity, water. Flat un-notched, tensile specimens were cycled under load control, with R=0.1, and with a saw-tooth wave form (with a loading time of 30 seconds and an unloading time of 3 seconds). Crack initiation was followed by periodically stopping the test and replicating the surface. The tests were performed at 177°C, in water containing 8ppm O2. H2SO4 additions were also made in some tests to raise the conductivity of the water from 0.06 ?S/cm to 0.4-0.5?S/cm. The crack initiation and growth data are correlated with the water chemistry of the test.

Download or read book Crack Initiation and Crack Growth Behavior of Carbon and Low alloy Steels written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Section III of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. These curves were based on tests of smooth polished specimens at room temperature in air. The effects of reactor coolant environments are not explicitly addressed by the Code design curves, but recent test data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be a factor of[approx]70 shorter than in air. Results of fatigue tests that examine the influence of reactor environment on crack imitation and crack growth of carbon and low-alloy steels are presented. Crack lengths as a function of fatigue cycles were determined in air by a surface replication technique, and in water by block loading that leaves marks on the fracture surface. Decreases in fatigue life of low-alloy steels in high-dissolved-oxygen (DO) water are primarily caused by the effects of environment during early stages of fatigue damage, i.e., growth of short cracks100[micro]m in depth. For crack sizes of100[micro]m, crack growth rates in high-DO water are higher than in air by one order of magnitude. The effects of LWR environments on growth of short cracks are discussed.

Download or read book Fatigue Fracture in a High strength Low alloy Steel written by K. R. L. Thompson and published by . This book was released on 1968 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of strength and stress level upon the mode and rate of fatigue crack growth in A1S14340 steel was studied by electron microfractography. It is shown that the mode of crack growth at high-strength levels is by a combination of transgranular striation formation and intergranular prior austenite grain boundary cracking, whereas in the lower-strength material only transgranular fracture occurs. The effect of stress level is found to alter slightly the proportion of the two fracture modes. At high-strength levels, measurement of striation spacing at various crack lengths indicates that the rate of crack growth is a function of the applied stress and crack length. Using this relationship it is shown that as the applied stress decreases, crack initiation becomes increasingly important in determining fatigue life. (Author).

Download or read book Thermomechanical Processing of High Strength Low Alloy Steels written by Imao Tamura and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermomechanical Processing of High-Strength Low-Alloy Steels considers some advanced techniques and metallurgical bases for controlled-rolling. This book contains 12 chapters. In Chapter 1, the purpose of thermomechanical processing and historical survey is described, while in Chapter 2, the kinetics of phase transformations and refinement of grain size in steels are elaborated. The techniques and metallurgical bases for controlled-rolling in the recrystallization, non-recrystallization, and (? + y) regions are reviewed in Chapters 3 to 5. Chapters 6 and 7 discuss the deformation resistance during hot-rolling and restoration processes. The phase transformations during cooling following hot-rolling are mentioned in Chapter 8, followed by a summarization of the effects of alloying elements in Chapter 9. Chapters 10 and 11 deal with the mechanical properties of controlled-rolled steel and prediction and control of microstructure and properties by thermomechanical processes. The problems faced and possibilities for future developments are stated in the last chapter. This publication is recommended for physicists, metallurgists, and researchers concerned with controlled-rolling, including non-specialists who have some knowledge of metallurgy.

Download or read book Fracture Mechanics written by Thomas A. Cruse and published by ASTM International. This book was released on 1988 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Initiation in Carbon and Low alloy Steels in Light Water Reactor Environments written by and published by . This book was released on 1998 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Section 111 of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. The effects of reactor coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of light water reactor (LWR) coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be shorter than those in air by a factor of H"0. The crack initiation and crack growth characteristics of carbon and low-alloy steels in LWR environments are presented. Decreases in fatigue life of these steels in high-dissolved-oxygen water are caused primarily by the effect of environment on growth of short cracks

Download or read book Corrosion fatigue of high strength low alloy steels in aqueous chloride environments written by R. P. Gangloff and published by . This book was released on 1988 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of the Environment on the Initiation of Crack Growth written by William Alan Van der Sluys and published by ASTM International. This book was released on 1997 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Published Data on Ductile Initiation Fracture Toughness of Low Alloy Structural Steels written by F. Ebrahimi and published by . This book was released on 1988 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published data on ductile initiation fracture toughness, namely J-integral (Ji) and crack tip opening displacement (?i), of high-strength low-alloy steels with 275 MPa (40 ksi) minimum yield strength have been compiled along with material and testing parameters. Yield strength (?y) has been chosen as the main parameter for evaluating the compiled data. The compiled Ji and ?i data showed a large range of variation at a given strength level. In an attempt to identify the testing parameters that contribute to this variation, the compiled data have been classified into four categories: (1) valid-standard, (2) valid-nonstandard, (3) invalid-standard, and (4) invalid-nonstandard. The critical review of sorted data has revealed that (1) microstructure, (2) testing method, and (3) validity contribute to both the scatter and the behavior of Ji values as a function of yield strength. The differences observed in the behavior of various sets of data are discussed considering the physical process of ductile crack initiation at the crack tip. The correlation between Ji and ?i was investigated using linear regression analysis. The slope of the Ji/?y versus ?i plot was found to be in the range 1.7 to 2.0.

Download or read book Advances in Applied Mechanics written by and published by Elsevier. This book was released on 2007-04-04 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major developments in the fields of fluid and solid mechanics are scattered throughout an array of technical journals, often making it difficult to find what the real advances are, especially for a researcher new to the field or an individual interested in discovering the state-of-the-art in connection with applications. The Advances in Applied Mechanics book series draws together recent significant advances in various topics in applied mechanics. Published since 1948, Advances in Applied Mechanics aims to provide authoritative review articles on topics in the mechanical sciences, primarily of interest to scientists and engineers working in the various branches of mechanics, but also of interest to the many who use the results of investigations in mechanics in various application areas such as aerospace, chemical, civil, environmental, mechanical and nuclear engineering. Advances in Applied Mechanics continues to be a publication of high visibility and impact. Review articles are provided by active, leading scientists in the field by invitation of the editors. Many of the articles published have become classics within their fields. Volume 41 in the series contains articles on topological fluid mechanics, electrospinning, vortex dynamics and self-assembly. Covers all fields of the mechanical sciences Highlights classical and modern areas of mechanics that are ready for review Provides comprehensive coverage of the field in question

Download or read book Fracture Mechanics Applications and Challenges written by M. Fuentes and published by Elsevier. This book was released on 2000-09-13 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains 15 fully peer-reviewed Invited Papers which were presented at the 13th Biennial European Conference on Fracture and is a companion to the CD-ROM http://www.elsevier.com/locate/isbn/008043701xProceedings. The organisers of the ECF 13 opted from the very beginning for an application-orientated conference, and consequently, this book contributes to the understanding of fracture phenomena, and disseminates fracture concepts and their application to the solution of engineering problems to practitioners in a wide range of fields. The fields covered in this book can be broadly classified into: elastic-plastic fracture mechanics, fracture dynamics, fatigue and interactive processes, failure, structural integrity, coatings and materials, with applications to the following industrial sectors: transport, aerospace engineering, civil engineering, pipelines and automotive engineering.

Download or read book CRACK INITIATION AND GROWTH CONSIDERATIONS FOR LANDING GEAR STEEL WITH EMPHASIS ON AERMET 100 written by A-5B Gears, Struts and Couplings Committee and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steel alloys, such as AF1410 (AMS 6527, UNS K92571) and AerMet 100 (AMS 6532), have been developed which have improved Fracture Toughness characteristics compared to the current landing gear steel alloy, 300M (AMS 6419 and AMS 6257, MIL-S-8844, UNS K44220). The 300M steel is the most widely used material in current landing gear designs. It has been successfully used in thousands of applications. The use of the 300M material necessitates a safe life design criterion where components are retired after one-fourth to one-sixth the laboratory test life. This criterion was established in part due to the relatively low fracture toughness of low-alloy steel in the 260 to 300 ksi strength range.The high fracture tough alloys give comparable strength levels with an increase in fracture toughness and better resistance to stress corrosion cracking. These alloys may make possible the consideration of new procedures for operation, maintenance, and inspection. For the present, these materials in the 220 to 280 ksi strength range, cannot be certified to damage tolerant design criteria. They may not yield critical cracks readily detectable using normal in-service inspection methods. Even though they may not qualify as damage tolerant in single load path applications, the improved mechanical properties alone may justify the consideration of these materials, especially in corrosive environments. In the future, they may allow on-condition maintenance, crack growth monitoring, and increased potential for rework.This document identifies several available materials. It compares properties of selected low-alloy steels to the higher alloyed steels. It also compares failure modes, maintenance, and inspection techniques. Although cost should be a factor when considering the material selection for landing gear application, this document will only focus on the technical aspects.

Download or read book Fracture Mechanics written by National Symposium on Fracture Mechanics and published by ASTM International. This book was released on 1979 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Investigation of Elevated Temperature Fatigue Crack Initiation in 2 and 1 4 CR 1 MO Low Alloy Steel written by and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental effects in elevated temperature fatigue have been extensively studied and reported in the literature for 2 1/4 Cr-1 Mo steel. The results of cycles to failure (lumped initiation and propagation life) verses strain range have shown drastic reductions in fatigue life with a dwell period at compressive strains in each loading cycle. This thesis has separately examined the crack initiation and propagation stages for several specimens tested in air at 538 deg C without dwell and a single specimen with a five minute compressive dwell. With dwell, the crack initiation stage was severely reduced (by a factor greater than eleven) relative to testing without dwell. The results clearly indicate that oxide cracking is a precursor to crack initiation in the substrate. It is concluded that the fatigue life of this alloy must be estimated based on the crack propagation characteristics alone, since crack initiation can be expected very clearly (i.e., first few cycles) for any practical environment. Originator supplied keywords include: Fatigue, oxide cracking, 2 1/4 Cr - Mo Steel.

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 Gigacycle Fatigue in Mechanical Practice written by Claude Bathias and published by CRC Press. This book was released on 2004-09-13 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by pioneers in the study and analysis of very high cycle fatigue this text brings together the most recent findings on gigacycle fatigue phenomena, focusing on improving the reliability and performance of key engine and machine components. This reference reflects the explosion of new concepts, testing methods, and data on very high cycle fa