Fatigue Testing
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Visual Examination and Light Microscopy
ASM Handbook, Volume 12: Fractography Copyright © 1987 ASM International® ASM Handbook Committee, p 91-165 All rights reserved. DOI: 10.1361/asmhba0001834 www.asminternational.org Visual Examination and Light Microscopy George F. Vander Voort, Carpenter Technology Corporation THE VISUAL EXAMINATION of fractures by light microscopy. Interesting features can be sections, to determine the origin of the failure, is deeply rooted in the history of metals pro- marked with a scribe, microhardness indents, and to separate the fractures according to the duction and usage, as discussed in the article or a felt-tip pen and then examined by SEM time sequence of failure, that is, which frac- "History of Fractography" in this Volume. and other procedures, such as energy- tures existed before the event versus which ones This important subject, referred to as macro- dispersive x-ray analysis, as required. occurred during the event. This article will fractography, or the examination of fracture The techniques and procedures for the visual assume that such work has already been accom- surfaces with the unaided human eye or at low and light microscopic examination of fracture plished and will concentrate on fracture exam- magnifications (--<50), is the cornerstone of surfaces will be described and illustrated in this ination and interpretation. Other related topics failure analysis. In addition, a number of qual- article. Results will also be compared and specific to failure analyses are discussed in ity control procedures rely on visual fracture contrasted with those produced by electron Volume 11 of the 9th Edition of Metals Hand- examinations. For failure analysis, visual in- metallographic methods, primarily SEM. -
Corrosion Fatigue: Type 304 Stainless Steel in Acid-Chloride and Implant Metals in Biological Fluid
76-9939 BOWERS, Davtd Francis, 1937- CORROSION FATIGUE: TYPE 304 STAINLESS STEEL IN ACID-CHLORIDE AND IMPLANT METALS IN BIOLOGICAL FLUID. The Ohio State University, Ph.D., 1975 Engineering, metallurgy Xerox University Microfilms, Ann Arbor, Michigan 48ioe CORROSION FATIGUE: TYPE 304 STAINLESS STEEL IN ACID-CHLORIDE AND IMPLANT METALS IN BIOLOGICAL FLUID Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University by David Francis Bowers, B.S., M.S. Metallurgical Engineering The Ohio State University 1975 Approved by (dviser Department of Metallurgical Engineering Reading Committee: Dr. Mars G. Fontana Dr. Frank Beck Dr. John P. Hirth To My Wife and Daughter TABLE OF CONTENTS Page ACKNOWLEDGEMENTS.......................................... iv VITA........................................................ vi LIST OF TABLES............................................. viii LIST OF FIGURES... ...................... x INTRODUCTION.................. .. ......................... 1 I. LITERATURE SURVEY..................... 4 1.1 Concepts and Theory of Fatigue Crack Growth.. 4 1.2 Fracture Mechanics Approach to Crack Growth in Engineering Structures..................... 18 1.3 Effect of Microstructure on Fatigue Cracking Growth................................ 24 1.4 Mechanical Variables in Corrosion Fatigue.... 41 1.5 Environmental Interaction with Fatigue Crack Growth.................................... 59 II. EXPERIMENTAL DETAILS............................... -
Corrosion-Fatigue Evaluation of Uncoated Weathering Steel Bridges
applied sciences Article Corrosion-Fatigue Evaluation of Uncoated Weathering Steel Bridges Yu Zhang, Kaifeng Zheng, Junlin Heng * and Jin Zhu Department of Bridge Engineering, School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China * Correspondence: [email protected]; Tel.: +86-182-8017-6652 Received: 19 July 2019; Accepted: 19 August 2019; Published: 22 August 2019 Featured Application: The new findings highlight the enhancement in corrosion-fatigue performance of steel bridges by using the uncoated weathering steel. Besides, an innovative approach has been established to simulate the corrosion-fatigue process in uncoated weathering steel bridges, providing deep insights into the service life of the bridges. The approaches suggested in the article can be used (not limited to) as a reference for the research and design of uncoated weathering steel bridges. Abstract: Uncoated weathering steel (UWS) bridges have been extensively used to reduce the lifecycle cost since they are maintenance-free and eco-friendly. However, the fatigue issue becomes significant in UWS bridges due to the intended corrosion process utilized to form the corrodent-proof rust layer instead of the coating process. In this paper, an innovative model is proposed to simulate the corrosion-fatigue (C-F) process in UWS bridges. Generally, the C-F process could be considered as two relatively independent stages in a time series, including the pitting process of flaw-initiation and the fatigue crack propagation of the critical pitting flaw. In the proposed C-F model, Faraday’s law has been employed at the critical flaw-initiation stage to describe the pitting process, in which the pitting current is applied to reflect the pitting rate in different corrosive environments. -
Estimating the Fatigue Stress Concentration Factor of Machined Surfaces D
International Journal of Fatigue 24 (2002) 923–930 www.elsevier.com/locate/ijfatigue Estimating the fatigue stress concentration factor of machined surfaces D. Arola *, C.L. Williams 1 Department of Mechanical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA Received 18 December 2000; received in revised form 12 September 2001; accepted 19 December 2001 Abstract In this study the effects of surface texture on the fatigue life of a high-strength low-alloy steel were evaluated in terms of the apparent fatigue stress concentration. An abrasive waterjet was used to machine uniaxial dogbone fatigue specimens with specific surface quality from a rolled sheet of AISI 4130 CR steel. The surface texture resulting from machining was characterized using contact profilometry and the surface roughness parameters were used in estimating effective stress concentration factors using the Neuber rule and Arola–Ramulu model. The steel specimens were subjected to tension–tension axial fatigue to failure and changes 3Յ Յ 6 in the fatigue strength resulting from the surface texture were assessed throughout the stress–life regime (10 Nf 10 cycles). It was found that the fatigue life of AISI 4130 is surface-texture-dependent and that the fatigue strength decreased with an increase in surface roughness. The fatigue stress concentration factor (Kf) of the machined surfaces determined from experiments was found to range from 1.01 to 1.08. Predictions for the effective fatigue stress concentration (K¯ f) using the Arola–Ramulu model were within 2% of the apparent fatigue stress concentration factors estimated from experimental results. 2002 Published by Elsevier Science Ltd. -
Corrosion Fatigue of Austenitic Stainless Steels for Nuclear Power Engineering
metals Article Corrosion Fatigue of Austenitic Stainless Steels for Nuclear Power Engineering Irena Vlˇcková 1,*, Petr Jonšta 2, ZdenˇekJonšta 2, Petra Vá ˇnová 2 and Tat’ána Kulová 2 1 RMTSC, Material & Metallurgical Research Ltd., Remote Site Ostrava, VÚHŽ a.s., Dobrá 739 51, Czech Republic 2 Department of Materials Engineering, VŠB-Technical University of Ostrava, Ostrava 708 33, Czech Republic; [email protected] (P.J.); [email protected] (Z.J.); [email protected] (P.V.); [email protected] (T.K.) * Correspondence: [email protected]; Tel.: +420-558601257 Academic Editor: Hugo F. Lopez Received: 21 September 2016; Accepted: 8 December 2016; Published: 16 December 2016 Abstract: Significant structural steels for nuclear power engineering are chromium-nickel austenitic stainless steels. The presented paper evaluates the kinetics of the fatigue crack growth of AISI 304L and AISI 316L stainless steels in air and in corrosive environments of 3.5% aqueous NaCl solution after the application of solution annealing, stabilizing annealing, and sensitization annealing. Comparisons were made between the fatigue crack growth rate after each heat treatment regime, and a comparison between the fatigue crack growth rate in both types of steels was made. For individual heat treatment regimes, the possibility of the development of intergranular corrosion was also considered. Evaluations resulted in very favourable corrosion fatigue characteristics of the 316L steel. After application of solution and stabilizing annealing at a comparable DK level, the fatigue crack growth rate was about one half compared to 304L steel. After sensitization annealing of 316L steel, compared to stabilizing annealing, the increase of crack growth rate during corrosion fatigue was slightly higher. -
The Environmental Effect on Corrosion Fatigue Behavior of Austenitic Stainless Steels
The Environmental Effect on Corrosion Fatigue Behavior of Austenitic Stainless Steels by Lun Yu B.S. Nuclear Engineering (2013) Shanghai Jiao Tong University SUBMITTED TO THE DEPARTMENT OF NUCLEAR SCIENCE AND ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN NUCLEAR SCIENCE AND ENGINEERING AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY September, 2017 © 2017 Massachusetts Institute of Technology. All rights reserved. Signature of Author: _____________________________________________________________ Lun Yu Department of Nuclear Science and Engineering August 25, 2017 Certified by: __________________________________________________________________ Ronald G. Ballinger Professor of Nuclear Science and Engineering, Materials Science and Engineering Thesis Supervisor Certified by: ___________________________________________________________________ Michael P. Short Assistant Professor of Nuclear Science and Engineering Thesis Reader Accepted by: ___________________________________________________________________ Ju Li Battelle Energy Alliance Professor of Nuclear Science and Engineering, Professor of Materials Science and Engineering Chair, Department Committee on Graduate Students This page was left blank intentionally The Environmental Effect on Corrosion Fatigue Behavior of Austenitic Stainless Steels by Lun Yu Submitted to the Department of Nuclear Science and Engineering on September 1, 2017 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Nuclear Science and -
10Th International Congress on Marine Corrosion and Fouling, University of Melbourne, February 1999
10th International Congress on Marine Corrosion and Fouling, University of Melbourne, February 1999 Additional Papers John A Lewis (Editor) Maritime Platforms Division Aeronautical and Maritime Research Laboratory DSTO-GD-0287 ABSTRACT This volume contains nineteen papers from the 10th International Congress on Marine Corrosion and Fouling, held at the University of Melbourne in Melbourne, Australia, in February 1999. The scope of the congress was to enhance scientific understanding of the processes and prevention of chemical and biological degradation of materials in the sea. Papers in this volume range across the themes of marine biofilms and bioadhesion, macrofouling processes and effects, methods for prevention of marine fouling, biocides in the marine environment, biodeterioration of wood in the sea, and marine corrosion. RELEASE LIMITATION Approved for public release Published by DSTO Aeronautical and Maritime Research Laboratory 506 Lorimer St Fishermans Bend, Victoria 3207 Australia Telephone: (03) 9626 7000 Fax: (03) 9626 7999 © Commonwealth of Australia 2001 AR-011-880 May 2001 APPROVED FOR PUBLIC RELEASE 10th International Congress on Marine Corrosion and Fouling, University of Melbourne, February 1999 Additional Papers Executive Summary The fouling and corrosion of vessels and structures immersed in the sea continues to pose significant economic and operational costs to the owner. Fouling growth can interfere with the operation of submerged equipment, impose increased loading stresses and accelerate corrosion on marine structures, and adversely affect the performance of ships by increasing hydrodynamic drag, which necessitates the use of more power and fuel to move the ship through the water. Similarly, marine corrosion and biodegradation of materials can compromise the operation and structural integrity of vessels, structures and other immersed equipment. -
Four Types of Heat Exchanger Failures
Four Types of Heat Exchanger Failures . mechanical, chemically induced corrosion, combination of mechanical and chemically induced corrosion, and scale, mud, and algae fouling By MARVIN P. SCHWARTZ, Chief Product Engineer, ITT Bell & Gossett a unit of Fluid Handling Div., International Telephone & Telegraph Corp , Skokie IL Hcat exchangers usually provide a long service life with Maximum recommended velocity in the tubes and little or no maintenance because they do not contain any entrance nozzle is a function of many variables, including moving parts. However, there are four types of heat tube material, fluid handled, and temperature. Materials exchanger failures that can occur, and can usually be such as steel, stainless steel, and copper-nickel withstand prevented: mechanical, chemically induced corrosion, higher tube velocities than copper. Copper is normally combination of mechanical and chemically induced limited to 7.5 fps; the other materials can handle 10 or 11 corrosion, and scale, mud. and algae fouling. fps. If water is flowing through copper tubing, the velocity This article provides the plant engineer with a detailed should be less than 7.5 fps when it contains suspended look at the problems that can develop and describes the solids or is softened. corrective actions that should be taken to prevent them. Erosion problems on the outside of tubes usually result Mechanical-These failures can take seven different from impingement of wet, high-velocity gases, such as forms: metal erosion, steam or water hammer, vibration, steam. Wet gas impingement is controlled by oversizing thermal fatigue, freeze-up, thermal expansion. and loss of inlet nozzles, or by placing impingement baffles in the cooling water. -
Investigation of Corrosion Fatigue Phenomena in Transient Zone of Mechanical Drive Steam Turbines and Its Preventive Measures
Proceedings of the Second Middle East Turbomachinery Symposium 17 – 20 March 2013, Doha, Qatar Investigation of Corrosion Fatigue Phenomena in Transient Zone of Mechanical Drive Steam Turbines and its Preventive Measures by Satoshi Hata Engineering and Design Division Mitsubishi Heavy Industries, Compressor Corporation Naoyuki Nagai Hiroshima Research & Development Center Mitsubishi Heavy Industries, Ltd. Norihito Fujimura MCO Saudi Arabia, LCC. (MCOSA) Mitsubishi Heavy Industries, Compressor Corporation Satoshi Hata ABSTRACT Satoshi Hata is a Group Manager For mechanical drive steam turbines, the investigation within the Turbo Machinery results of corrosion fatigue phenomena in the transient zone Engineering Department, Mitsubishi are introduced, including basic phenomena on expansion Heavy Industries, Ltd., in Hiroshima, line and actual design and damage experience. These results Japan. He has 30 year experience in were analyzed from the standpoint of stress intensity during R&D for nuclear uranium centrifuges, turbomolecular pumps, heavy-duty the start of cracking. In order to resolve such problems, gas turbines, steam turbines and preventive coating and blade design methods against fouling compressors. Mr. Hata has B.S., M.S. and corrosive environments are developed. Detailed and Ph.D. degrees (in Mechanical evaluation test results are given for coating performance Engineering) from Kyusyu Institute of using a unique test procedure simulating fouling phenomena Technology. and washing conditions. Finally, the results of the Naoyuki -
Improved Fatigue Test Specimens with Minimum Stress Concentration Effects1
IMPROVED FATIGUE TEST SPECIMENS WITH MINIMUM STRESS CONCENTRATION EFFECTS1 Daniel de Albuquerque Simões2 Jaime Tupiassú Pinho de Castro3 Marco Antonio Meggiolaro3 Abstract The American Standard for Testing and Materials (ASTM) has standardized numerous mechanical tests such as the constant amplitude axial fatigue test of metallic materials (E 466–96), the strain-controlled fatigue testing (E 606–92) and the strain-controlled axial-torsional fatigue testing with thin-walled tubular specimens (E 2207–02). The specimens for such tests must have notches to connect their uniform test section to the larger heads required to grip them. The usual practice is to specify notches with as large as possible constant radius roots, since they can be easily fabricated in traditional machine tools. However, notches with properly specified variable radius may have much lower stress concentration factors than those obtainable by fixed notch root radii. The objective of this study is to analyze the stress distribution in these specimens using the finite element method and to quantify the stress concentration improvements achievable by optimizing variable radius notches for typical push-pull, rotary bending and alternate bending fatigue test specimens by redesigning the specimen geometry without changing their overall dimensions. Key words: Stress concentration factor; Shape optimization; Finite element methods. CORPOS DE PROVA DE FADIGA COM CONCENTRAÇÃO DE TENSÃO REDUZIDA Resumo A ASTM (The American Standard for Testing and Materials) padronizou inúmeros testes mecânicos, como por exemplo, o teste de fadiga de amplitude constante para materiais metálicos (E466–96), o teste de fadiga com deformação controlada (E 606–92) e o teste de fadiga de torção axial de corpos de prova tubulares (E 2207–02). -
Corrosion-Fatigue Testing on Steel Grades with Different Heat and Surface Treatments Used in Rock-Drilling Applications
DEGREE PROJECT IN MATERIALS SCIENCE AND ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2016 CORROSION-FATIGUE TESTING ON STEEL GRADES WITH DIFFERENT HEAT AND SURFACE TREATMENTS USED IN ROCK-DRILLING APPLICATIONS LUIS MIGUEL BÉJAR INFANTE KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF INDUSTRIAL ENGINEERING AND MANAGEMENT Abstract Corrosion fatigue is a common failure mechanism in rock drilling components and many other mechanical parts subjected to cyclic loads in corrosive environments. A crucial part in the design of such components resides in the selection of the right materials for the application, which ideally involves testing and comparison of their performance under working conditions. The present work was performed with the purpose of designing a corrosion-fatigue testing method that would allow the designer to compare the performance of different materials exposed to corrosion fatigue, permitting also the comparison with results from dry fatigue testing. The method was designed for rotating-bending machines. Two different steel grades were used during the work, one through hardened and one case hardened. The effect of these heat treatments and of shot peening over corrosion-fatigue behaviour were studied using the proposed method. It was proven that the testing speed has a strong impact on the fatigue life of steel. It was found that, at a fixed stress level, the case hardened and shot peened steel reached 3X10^6 cycles at 2300 rpm, while it failed at only 5X10^5 cycles with a testing speed of 500 rpm. A large beneficial influence of the shot peening was demonstrated. It was also observed that, at fixed testing speed, the shot peening on the through hardened steel can increase its fatigue strength from 190 MPa to 600 MPa under corrosion fatigue. -
Mechanical Fatigue of Metals
354.pdf A SunCam online continuing education course Mechanical Fatigue of Metals by Gerald O. Davis, P.E. 354.pdf Mechanical Fatigue of Metals A SunCam online continuing education course 1. Introduction - Overview of Mechanical Fatigue of Metals Among the several ways that metallic engineering materials may fail in service, mechanical fatigue is typically the most common. The percentages of the total mechanical failures that are due to fatigue vary by different sources from 50% to as much as 80 to 90 %. Some examples of applications in which fatigue failures occur include rotating shafts, bearings, gears, the wings and pressurized fuselages of aircraft, pipelines and tubes in shell-and-tube heat exchangers. There are many other examples. The variable loads and changing stresses that occur in fatigue have unique effects on the services lives of engineering alloys that don’t apply in situations where the only stresses acting are static. In situations where loading and resulting stresses don’t vary, resistance to failures becomes relatively straight forward. They can be adequately addressed by assuring working stresses, i.e., allowable stresses, are less than the yield, or ultimate tensile strength or ultimate shear strength (depending on the application) of the metal selected after applying a factor of safety to cover unknown aspects. Mechanical fatigue is significantly more complex. It is essential to realize that metal mechanical properties generated from standard, constant load tests should never be applied directly to fatigue applications. Fatigue often produces failure and complete metal separation when the maximum, fluctuating stress is well below the yield or ultimate tensile strength of the metal.