Download or read book Fatigue Crack Propagation in Some Ultrahigh Strength Steels written by Che-Yu Li and published by . This book was released on 1967 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue-crack propagation studies were carried out on some ultrahigh-strength steels in controlled environments using the fracture-mechanics approach. The steels investigated include a medium-carbon low-alloy ultrahigh-strength steel tempered to two strength and toughness levels, a 250-grade 18Ni maraging steel, and a 300-grade 18Ni steel. The results indicate that, in the inert environment, the rates of fatigue-crack propagation in these steels are about the same and show no obvious correlation with other mechanical properties of the steels. The sensitivity of the rates of fatigue-crack propagation to the presence of moisture in the test environment shows rough correlation with plane-strain fracture toughness for steels of similar composition. The role of water vapor in promoting fatigue-crack propagation is considered. The results are also discussed in terms of existing theories and metallographic observations.

Download or read book Effect of Microstructure and Internal Hydrogen on Fatigue Crack Propagation of Ultrahigh Strength Steels written by Cheruvu Narayana Sastry and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Fatigue Crack Propagation in Medium Strength Steels written by Stig Wästberg and published by . This book was released on 1980 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Strength and Grain Size on Near threshold Fatigue Crack Growth in Ultra high Strength Steel written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue tests were performed on ultra-high strength steels to assess (i) the influence of strength at constant grain size, and (ii) the influence of grain size at constant strength, on threshold stress intensity and near-threshold crack propagation rates. The results constitute part of a larger program of research to characterize the microstructural influences on fatigue crack propagation at growth rates less than 10−5 mm/cycle in an attempt to provide a basis for the design of alloys resistant to low growth rate fatigue failure.

Download or read book Fatigue crack Propagation in High Yield strength Steels written by J. M. BARSOM and published by . This book was released on with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Propagation written by and published by . This book was released on 1967 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Untempered Ultra High Strength Steels of High Fracture Toughness written by Earl Randall Parker and published by . This book was released on 1974 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the present investigation was to establish, in high yield strength steels, relationships between microstructure, fracture toughness and fatigue crack growth. Extensive microstructural examination and characterization were conducted on as-quenched, and quenched and tempered AISI 4340 steel which was austenitized both at the conventional (870C) and the high (1200C) austenitizing temperatures. Changes in fracture toughness resulting from variations in austenitizing and tempering treatments were related to changes in the amount and distribution of retained austenite, the morphology and distribution of carbides, and the martensite substructure and morphology. The influence of microstructure on fatigue crack propagation was investigated in as-quenched, and quenched and tempered 5Mo-0.3C secondary hardening steel. (Modified author abstract).

Download or read book Load Interaction Effects on Fatigue Crack Propagation in High Strength Steels written by Dan K. Holm and published by . This book was released on 1985 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Propagation in the Intermediate and Near threshold Growth Regions of Several Low to Medium Strength Steels written by John A. Lewis and published by . This book was released on 1982 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report of NRL Progress written by Naval Research Laboratory (U.S.) and published by . This book was released on 1970 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Fractography written by Beachem CD. and published by ASTM International. This book was released on 1968 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 The Effect of Environment on Fatigue Crack Propagation in 4340 Steel written by Roger Charles Rowlands and published by . This book was released on 1972 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Propagation in High Strength Steel written by Keith Robin Lee Thompson and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Fatigue Crack Growth of Short Cracks in 300 M Ultra high Strength Steel written by John Toplosky and published by . This book was released on 1979 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Cycle Fatigue Behavior and Crack Propagation in Some Steels written by Saurindranath Majumdar and published by . This book was released on 1974 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous report, a fatigue crack propagation model was analyzed by considering fatigue crack propagation as a sequence of fatigue crack initiation events. This permitted correlation to be made between the fatigue crack growth resistance and low cycle fatigue properties of metals. Four steels were tested for low cycle fatigue behavior at the University of Illinois. Good correlation was obtained between the theoretically predicted crack propagation rate based on the measured low cycle fatigue properties of the four metals and experimentally observed crack propagation rates that were reported in the literature. Further, good estimates of crack propagation rates can be obtained on the basis of static tensile properties of the metals alone where cyclic properties are not available. (Author).