Download or read book The Effect of Shot Peening Coverage on Residual Stress Cold Work and Fatigue in a Ni Cr Mo Low Alloy Steel written by and published by . This book was released on 2000 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The underlying motivation for this work was to test the conventional wisdom that 100% coverage by shot peening is required to achieve full benefit in terms of compressive residual stress magnitude and depth as well as fatigue strength. Fatigue performance of many shot peened alloys is widely reported to increase with coverage up to 100%, by many investigators and even in shot peening manuals.(1) The fatigue strength of some alloys is reported to be reduced by excessive coverage(2) Aerospace(3,4), automotive(5), and military(6) shot peening specifications require at least 100% coverage. Internal shot peening procedures of aerospace manufacturers may require 125% to 200% coverage. Most of the published fatigue data supporting the 100% minimum coverage recommendation was developed in fully reversed axial loading(2,7) or bending(8,9) with a stress ratio, R= Smin / Smax, of -1.
Download or read book Shot Peening written by Lothar Wagner and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shot peening has been proved to be a powerful instrument in enhancing the resistance of materials to various kinds of stress-induced damage, particularly against damage due to cyclic loading (fatigue) in air or in aggressive environments. As shot peening can be used for a wide variety of structural components irrespective of shape and dimensions, the number of shot peening applications in many industrial branches is increasing. The use of peen forming as a technique to form large metal parts into complicated shapes is also increasing, particularly in the aerospace industry. The Conference covers all aspects of the Science, Technology and Application of Shot Peening, and was intended to attract users, manufacturers as well as scientists working in the field of "Materials Treatment by Shot Peening". Emphasis was put on the current state of knowledge and research. This book offers scientists and engineers an unique opportunity to update their knowledge on shot peening.
Download or read book Laser Shock Peening written by K Ding and published by Woodhead Publishing. This book was released on 2006-01-16 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser shock peening (LSP) is a relatively new surface treatment for metallic materials. LSP is a process to induce compressive residual stresses using shock waves generated by laser pulses. LSP can greatly improve the resistance of a material to crack initiation and propagation brought on by cyclic loading and fatigue. This pioneering book was the first of its kind to consolidate scattered knowledge into one comprehensive volume. It describes the mechanisms of LSP and its substantial role in improving fatigue performance in terms of modification of microstructure, surface morphology, hardness and strength. In particular it describes numerical simulation techniques and procedures which can be adopted by engineers and research scientists to design, evaluate and optimise LSP processes in practical applications. - Provides for the first time, a comprehensive coverage of this important area - Written by two world renowned experts
Download or read book Shot Peening written by Kailash Chaudhary and published by Educreation Publishing. This book was released on with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the advantages of shot peening process in increasing fatigue strength of components subjected to high alternating stresses. The fields of application for shot peening include all metallic components, which are subject to fluctuating and fatigue loads. Additional advantages of using shot peening include design of lighter weight and lower cost components, prevention of stress corrosion, formation of lubrication pockets and compensation of manufacturing related surface defects.
Download or read book Shot Peening for Improved Fatigue Properties and Stress corrosion Resistance written by James Edward Campbell and published by . This book was released on 1971 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shot peening procedures developed over the past 40 years have resulted in substantial improvements in fatigue properties and stress corrosion resistance of high-strength alloys. These improvements have been observed in shot-peened specimens and components of high-strength steels, aluminum alloys, titanium alloys, and other engineering alloys. This report contains information on peening procedures that have been used in processing specimens and components to achieve these improvements in performance. Certain precautions are pointed out that should be observed in order to obtain the improved properties that have been attributed to the peening process. Some of the peening programs cited in this report indicate the peening intensities that resulted in the greatest benefit in performance based on test data covering a range of intensities, shot sizes, and other variables. (Author).
Download or read book The Effect of Shot peening on the Fatigue Limits of Four Connecting Rod Steels written by Mohammad-Mahdi Mirzazadeh and published by . This book was released on 2010 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work was carried out to study the effect of shot-peening on the fatigue behaviour of carbon steels. Differently heat treated medium and high carbon steel specimens were selected. Medium carbon steels, AISI 1141 and AISI 1151, were respectively air cooled and quenched-tempered. A high carbon steel, C70S6 (AISI 1070), was air cooled. The other material was a powder metal (0.5% C) steel. Each group of steels was divided into two. One was shot-peened. The other half remained in their original conditions. All were fatigue tested under fully reversed (R=-1) tension-compression loading conditions. Microhardness tests were carried out on both the grip and gage sections of selected non shot-peened and shot-peened specimens to determine the hardness profile and effect of cycling. Shot-peening was found to be deeper on one side of each specimen. Compressive residual stress profiles and surface roughness measurements were provided. Shot-peening increased the surface roughness from 0.26±0.03[mu]m to 3.60±0.44[mu]m. Compressive residual stresses induced by shot-peening reached a maximum of -463.9MPa at a depth of 0.1mm. The fatigue limit (N[dsim]106 cycles) and microhardness profiles of the non shot-peened and shot-peened specimens were compared to determine the material behaviour changes after shot-peening and cycling. Also their fatigue properties were related to the manufacturing process including heat and surface treatments. Comparing the grip and gage microhardness profiles of each steel showed that neither cyclic softening nor hardening occurred in the non shot-peened condition. Cyclic softening was apparent in the shot-peened regions of all steels except powder metal (PM) steel. The amount of softening in the shot-peened region was 55.0% on the left side and 73.0% on the right in the AISI 1141 steel, 46.0% on the left side and 55.0% on the right in the C70S6AC steel and 31.0% on the right side in AISI 1151QT steel. Softening was accompanied by a decrease in the depth of surface hardness. It is suggested that although the beneficial effects of shot peening, compressive residual stresses and work hardening, were offset by surface roughness, crack initiation was more likely to occur below the surface. Surface roughness was not a significant factor in controlling the fatigue lives of AISI 1141AC and C70S6 steels, since they were essentially the same for the non shot-peened and shot-peened conditions. Shot-peening had very little effect on the push-pull fatigue limit of C70S6 steel ( -2.1%), and its effect on AISI 1141AC steel was relatively small (6.0%). However, the influence of shot-peening on the AISI 1151QT and PM steels was more apparent. The fatigue limit of the PM steel increased 14.0% whereas the fatigue limit of the AISI 1151QT steel decreased 11.0% on shot peening.
Download or read book Shot Peening written by H. Wohlfahrt and published by I R Publications, Limited. This book was released on 1987 with total page 1376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1994 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Residual Stress Distribution and Experimental Characterization of Shot Peening on AZ31B Rolled Sheet written by Amir Yazdanmehr and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The drive to reduce fossil fuel consumption due to its environmental impacts has generated renewed interest in employing magnesium (Mg), the lightest industrial metal, and its alloys in vehicle manufacturing. One of the qualifying metrics for structural application of Mg in transportation vehicles is its high durability. The low fatigue strength of these alloys has been an obstacle to using them in load-bearing components. Thus, methods for improving the fatigue properties of Mg alloys are of interest. Shot peening is a cold-working process employed to improve the fatigue properties of materials. The shot peening process induces compressive residual stress at the material's surface and at a layer in the order of a few hundred micrometers deep, which improves the fatigue life by retarding the crack initiation as well as growth; however, the increased surface roughness has a detrimental effect on fatigue life. These competing effects of peening have created interest in finding the optimum peening intensity that will maximize fatigue life. Modeling reduces the cost of experimentally evaluating optimum peening conditions. However, modeling the shot peening of Mg alloys remains complicated due to the anisotropic and asymmetric properties of wrought Mg alloys, and the complex unloading behavior and rate-sensitivity behavior of these materials. To address these challenges, a comprehensive experimental and numerical-analytical study of shot peening on AZ31B-H24 rolled sheet was conducted and is reported in this thesis. First residual stress distributions through the depth of the material were measured. Among the methods for residual stress measurement, X-ray diffraction (XRD) has attracted researchers' attention because: 1) it is a non-destructive method; 2) it can measure residual stress at the surface, and 3) the spatial resolution can be less than 0.3 mm. However, due to the low x-ray mass attenuation coefficient of Mg alloys, x-ray penetration in the material is significant which needs to be accounted for. The residual stresses in as-received and shot peened AZ31B-H24 rolled sheet samples were measured using the 2D-XRD method. The electro-polishing layer removal method was used to find the residual stress pattern through depth. Due to the high depth of penetration, a correction had to be made to account for the penetration depth. The results showed that the corrected residual stresses in a few tens of micrometers layer from the surface were different from the raw stresses. To better estimate the residual stress distribution in a few micrometers from the surface, the grazing-incidence x-ray diffraction (GIXD) method was applied to evaluate the stresses in the surface layer. This study also showed how small uncertainty in measuring the observed residual stress and in evaluating the depth of the polished area in layer removal leads to high uncertainty in the corrected residual stresses. The XRD results showed the creation of compressive residual stress through the depth as well as a good agreement between the XRD and hole-drilling and GIXD results. Modeling the shot peening process first requires an understanding of how Mg alloys behave at large strain values during loading-unloading. The tension-compression (TC) and compression-tension (CT) in the in-plane directions were obtained using an anti-buckling fixture. By comparing the compression part of the CT curves along the rolling direction (RD) with the ones using a cuboid sample, the negligible effect of using the anti-buckling fixture was shown. A novel fixture was designed to obtain the CT and TC curves in the through-thickness (normal direction: ND) of the rolled sheet, which is only 6.3 mm thick. FEM was employed to evaluate the consistent area for strain measurement using DIC in the designed setup. The CT and TC curves along ND were obtained using the new fixture. The results of the new fixture were verified by comparing the curves obtained by the new fixture in RD with those obtained by using the anti-buckling fixture. Different effects of shot peening on the AZ31B-H24 rolled sheet were characterized in this study by measuring the residual stress and micro-hardness distribution through the depth, followed by measuring surface roughness and texture evolution at the surface of samples shot peened under Almen intensities ranging from 0.05 mmN to 0.6 mmN. To obtain the optimum peening intensity, rotating bending fatigue tests were performed on peened samples at different intensities. It was found that increasing the peening intensity, increases the surface roughness and hardness at the surface layer. In addition, the depth of the maximum compressive stress and the depth of the induced compressive residual stress layer have a direct relation with the peening intensity. The material showed a high sensitivity to shot peening under different intensities, due to the over-peening effects in the peening on Mg alloys. Peening at the optimum intensity increases the fatigue strength moderately, from 130 MPa to 150 MPa. During investigations to find an accurate and a computationally efficient method for capturing the complex behavior of Mg alloys, it was found that stringent assumptions are needed to allow for a closed-form analytical solution when calculating residual stresses induced by shot peening. This limits the application of these models to idealized conditions. On the other hand, and because of the complex behaviors of Mg alloys, such as complex unloading behavior and rate-sensitivity, it is difficult to provide numerical solutions such as finite element that are capable of mimicking actual material's behavior once it is released from an over-strain loading state. Moreover, modeling full coverage shot peening condition is time-consuming and computationally expensive. A single-shot finite element model was combined with an analytical model using actual loading-unloading material behavior to propose a hybrid FEM-analytical model for prediction of the residual stress distribution in shot peening. First, the shot peening process was divided into a loading phase, modeling the impact of a shot and substrate, and an unloading phase, modeling the rebounding of the shot. Finite element was employed to model a single shot impingement on a substrate using the actual loading properties of the substrate. Using the results of the loading phase, an analytical model was proposed to predict stresses due to the unloading phase, using the actual unloading behavior of the material. The proposed hybrid model accounts for the actual behavior of a material, actual elastic-plastic contact analysis, strain rate effect, and friction. The model was then verified by predicting residual stresses induced in a SAE1070 and an Al2024-T351 sheet. Results were compared with the available experimental results and showed close agreements. The application of the proposed hybrid numerical-analytical model was extended to use with an asymmetric and anisotropic material that also has complex unloading behavior, i.e., Mg alloys. First, the loading state of material under peening and the effects of the material's asymmetry and anisotropy were discussed, then the numerical modeling of the loading step was provided. Finally, the actual unloading curves, measured using the designed fixture, of the material were used to estimate the residual stress profiles. The strain rate effect was also considered in the modeling. The results were matched closely with the XRD and hole-drilling experimental measurements.
Download or read book Shot Peening written by John S. Eckersley and published by . This book was released on 1991 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Shot Peening Prior to Electroplating on the Fatigue Properties of an Alloy Steel written by N. B. Brown and published by Queen's Printer. This book was released on 1958 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Treatment Effects on Aermet 100 Steel Part 1 Shot Peening Effect on Corrosion and Fatigue of Aermet 100 Steel written by and published by . This book was released on 1996 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was conducted to identify the effect of shot peening on the corrosion and fatigue behavior of AerMet 100 steel. The specimens were shot-peened with hard cast steel shot, and the induced residual stress profile was determined with the aid of X-ray diffraction. Subsequently, the specimens were undergone to direct tension stress corrosion and immersion corrosion in an aqueous 3.5% NaC1 solution, salt spray corrosion in two separate fog chambers for atomized aqueous 5% NaC1 solution with and without SO2 gas, and fatigue test in a laboratory environment. The shot peening induced a residual compressive stress 1,130 MPa at 0.03 mm depth in the specimen. The shot peening did not change the susceptibility of AerMet 100 steel to stress corrosion, but reduced the resistance to immersion corrosion and salt spray corrosion. This unfavorable effect is associated with the surface cold work and greater exposure area generated by the shot peening process. On the other hand, the shot peening extended the fatigue life of AerMet 100 steel.
Download or read book Effect of NaC1 and Shot Peening on the Corrosion Fatigue of AISI 6150 Low alloy Steel written by Michael Steven Baxa and published by . This book was released on 1975 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shot Peening written by Wheelabrator Corporation, Mishawaka, Ind and published by . This book was released on 1959 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SAE Manual on Shot Peening written by Society of Automotive Engineers and published by . This book was released on 1953 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Residual Stresses 2016 written by Thomas M. Holden and published by Materials Research Forum LLC. This book was released on 2017-03-15 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the International Conference on Residual Stresses 10 and is devoted to the prediction/modelling, evaluation, control, and application of residual stresses in engineering materials. New developments, on stress-measurement techniques, on modelling and prediction of residual stresses and on progress made in the fundamental understanding of the relation between the state of residual stress and the material properties, are highlighted. The proceedings offer an overview of the current understanding of the role of residual stresses in materials used in wide ranging application areas.
Download or read book The Effect of Cold Work on the Thermal Stability of Residual Compression in Surface Enhanced IN718 written by and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhancement, the creation of a layer of residual compression at the surface of a component, is widely used to improve the fatigue life in the automotive and aerospace industries. The compressive layer delays fatigue crack initiation and retards small crack propagation. The benefits of surface enhancement are lost if the compressive layer relaxes at the operating temperature of the component. Surface enhancement methods producing minimal cold work are shown to produce the most thermally stable compression. The residual stress and cold work distributions developed in IN718 by shot peening, gravity peening, laser shock peening (LSP) and low plasticity burnishing (LPB) are compared. Estimation of cold work (equivalent true plastic strain) from x-ray diffraction line broadening is described. Thermal relaxation at temperatures ranging from 525 degrees C to 670 degrees C is correlated to the degree of cold working of the surface, independent of the method of surface enhancement. Highly cold worked (> 15%) shot peened surfaces are found to relax to half the initial level of compression in minutes at all temperatures investigated. The rapid initial relaxation is shown to be virtually independent of either time or temperature from 525 degrees C to 670 degrees C. The LPB process is described with application to IN718. High cycle fatigue performance after elevated temperature exposure is compared for surfaces treated by LPB and conventional (8A intensity) shot peening.
