scholarly journals Investigations on the influence of cold‐forming and associated residual stresses on the fatigue strength of thin‐walled details

ce/papers ◽  
2021 ◽  
Vol 4 (2-4) ◽  
pp. 505-510
Author(s):  
Thorben Geers ◽  
Benno Hoffmeister ◽  
Christoph Heinemeyer
Keyword(s):  
Fatigue Strength ◽  
Residual Stresses ◽  
Cold Forming ◽  
Thin Walled

OVAKO 803 J/EN 100CR6

Alloy Digest ◽  
2008 ◽  
Vol 57 (7) ◽  
Keyword(s):  
Fatigue Strength ◽  
North America ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Cold Forming ◽  
Bearing Steels

Abstract Ovako 100Cr6 comprises a group of through-hardening bearing steels with modification to improve machining, cold forming, and cleanliness for better fatigue strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, forming, and heat treating. Filing Code: SA-582. Producer or source: Ovako North America Inc.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

Correlation of Residual Stresses in the Fatigue Strength of Axles

1942 ◽  
Vol 9 (2) ◽  
pp. A85-A90
Author(s):  
O. J. Horger ◽  
H. R. Neifert
Keyword(s):  
Heat Treatment ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
High Surface ◽  
Full Size ◽  
Tensile Stresses ◽  
Compressive Stresses ◽  
Actual Service

Abstract The object of this paper is to present a correlation between residual stresses, obtained by heat-treatment, with fatigue values, determined from an investigation of full-size railroad axles. The axles tested were of both solid and tubular design and represent members which could be used under a car in actual service. It was found from these tests that high axle fatigue strength is associated with high surface residual compressive stresses, and lowest axle strength values with surface residual tensile stresses.

Effect of shot peening residual stresses and surface roughness on fretting fatigue strength of Al 7075-T651

2020 ◽  
Vol 142 ◽  
pp. 106004 ◽  
Author(s):  
Vicente Martín ◽  
Jesús Vázquez ◽  
Carlos Navarro ◽  
Jaime Domínguez
Keyword(s):  
Surface Roughness ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Shot Peening ◽  
Fretting Fatigue ◽  
Al 7075

Average Residual Stresses in Hard Physical Vapor Deposited (PVD) Coatings

2019 ◽  
Vol 799 ◽  
pp. 20-25
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Valdek Mikli ◽  
Eron Adoberg ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Front Surface ◽  
Back Surface ◽  
Length Variation ◽  
Pvd Coatings ◽  
Cross Sectional ◽  
Average Residual ◽  
Thin Walled ◽  
Compressive Residual Stresses ◽  
Very High

In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.

The Effect of Quench-Induced Residual Stresses on the Distortion of Machined Thin-Walled Parts

2015 ◽  
Vol 24 (10) ◽  
pp. 3933-3941 ◽  
Author(s):  
Soroush Masoudi ◽  
Ghasem Amirian ◽  
Ehsan Saeedi ◽  
Mohammad Ahmadi
Keyword(s):  
Residual Stresses ◽  
Thin Walled
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