Cold Working Method Retards Metal Fatigue Cracks

1986 ◽  
Vol 58 (2) ◽  
pp. 24-24
Keyword(s):  
Cold Working ◽  
Fatigue Cracks ◽  
Metal Fatigue ◽  
Working Method

Increasing Yield Strength of AISI 316L Plastically Deformed by Expanded Hole Techniques

2017 ◽  
Vol 901 ◽  
pp. 97-102
Author(s):  
Urip Agus Salim ◽  
Suyitno ◽  
Rahadyan Magetsari ◽  
Muslim Mahardika
Keyword(s):  
Numerical Simulation ◽  
Yield Strength ◽  
Residual Stresses ◽  
Strain Hardening ◽  
Cold Working ◽  
Small Crack ◽  
Aisi 316L ◽  
Hardening Mechanism ◽  
Working Method ◽  
Fatigue Mechanism

AISI 316L has been used to produce implant plates such as dynamic copmresion plates (DCP). The implant plates might experienced failure due to either suffer higher stresses exceeding the allowable maximum strenght or presents small crack growing through fatigue mechanism. Most of DCP fractures occured at the gliding holes region. This study conducted improving strength of DCP locally on the gliding holes. Strengthening on the gliding holes of DCP was performed by cold working method involving plastically deformation using an expanded hole technique. This study was conducted by both experimental and numerical simulation. Increasing strength locally on the gliding hole region was evaluated by measuring some parameters incorporated with strain hardening mechanism such as hardness and residual stresses. Increasing yields strength locally on the hole region was estimated by Takakuwa’s formulas. By this method, yields strength of the gliding hole of DCP made of AISI 316L increased from 325 MPa to be 600−1050 MPa.

Effect of cold working on the growth of fatigue cracks in steel SKhL-4

1968 ◽  
Vol 10 (7) ◽  
pp. 514-517
Author(s):  
S. I. Manevich ◽  
M. Ya. Shashin
Keyword(s):  
Cold Working ◽  
Fatigue Cracks

On the fatigue design method for high-speed railway axles

2001 ◽  
Vol 215 (2) ◽  
pp. 73-82 ◽  
Author(s):  
K Hirakawa ◽  
M Kubota
Keyword(s):  
Fatigue Strength ◽  
High Speed ◽  
Fatigue Cracks ◽  
Fretting Fatigue ◽  
Brake Disc ◽  
Metal Fatigue ◽  
High Speed Railway ◽  
Fatigue Design ◽  
Railway Axle ◽  
The Press

Fatigue failure of the railway axle, which has been a source of difficulty for engineers since railroad service started in the early part of the nineteenth century, was the beginning of the study of metal fatigue. In order to maintain the safety of a high-speed railway system, a large number of investigations and experiments have been carried out by outstanding researchers ever since, and many improvements have been made in the material, manufacturing, heat treatment and design methods. In comparing Japan and Europe on the fatigue design philosophy of the high-speed railway axle, it is recognized that there is a difference between the Japanese Shinkansen and the European TGV and ICE. The critical parts for fatigue strength are the press-fitted parts which suffer from fretting fatigue damage, such as the wheel seat, gear seat and brake disc seat. In Europe, the larger diameter of the press-fitted part makes the fillet the critical part. In Japan, however, the fatigue strength of the press-fitted part is increased by an induction hardening method. Also, a stress-relief groove is made at the closely press-fitted part of the axle. For several years, no fretting fatigue cracks in Shinkansen axles have been detected by magnetic particle inspection. It is noted that improvements over many years have been successful in achieving the safety of high-speed railway axles. These problems will be studied in this paper.

scholarly journals Short/small fatigue crack growth, thresholds and environmental effects: a tale of two engineering paradigms

2021 ◽  
Vol 39 (2) ◽  
pp. 165-175
Author(s):  
Russell J. H. Wanhill ◽  
Stefanie E. Stanzl-Tschegg
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Steam Turbine ◽  
Crack Growth ◽  
Environmental Effects ◽  
High Cycle Fatigue ◽  
Materials Science ◽  
Fatigue Cracks ◽  
Cycle Fatigue ◽  
Metal Fatigue

Abstract This paper results from mutual discussions on the review ‘When do small fatigue cracks propagate and when are they arrested?’ in Corrosion Reviews, 2019; 37(5): 397–418. These discussions have arisen from the two engineering paradigms characterizing our fatigue research: (i) an aerospace research and technology remit for metallic airframes, and (ii) a materials science research programme supporting a methodology for steam turbine low pressure (LP) blade operations. In our opinion, this paper is of interest for other investigators of metal fatigue with respect to design requirements, life predictions and assessments. In more detail, the paper considers the fatigue design methodologies for airframes and steam turbine LP blades. This includes short/small fatigue cracks, fatigue crack growth thresholds, high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF), and the relevance of environmental effects (corrosion and corrosion fatigue).

scholarly journals The Evaluation of Front Shapes of Through-the-Thickness Fatigue Cracks

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 403
Author(s):  
Behnam Zakavi ◽  
Andrei Kotousov ◽  
Ricardo Branco
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Closure ◽  
Crack Front ◽  
Fatigue Cracks ◽  
Numerical Approach ◽  
Metal Fatigue ◽  
Underlying Mechanisms ◽  
Actual Shape

Fatigue failure of structural components due to cyclic loading is a major concern for engineers. Although metal fatigue is a relatively old subject, current methods for the evaluation of fatigue crack growth and fatigue lifetime have several limitations. In general, these methods largely disregard the actual shape of the crack front by introducing various simplifications, namely shape constraints. Therefore, more research is required to develop new approaches to correctly understand the underlying mechanisms associated with the fatigue crack growth. This paper presents new tools to evaluate the crack front shape of through-the-thickness cracks propagating in plates under quasi-steady-state conditions. A numerical approach incorporating simplified phenomenological models of plasticity-induced crack closure was developed and validated against experimental results. The predicted crack front shapes and crack closure values were, in general, in agreement with those found in the experimental observations.

Technology of nuclear power plant pipelines’ joint welds’ reconditioning repair by surface cold working method

2021 ◽  
Author(s):  
O. V. Urazov ◽  
A. D. Danilov ◽  
K. Yu. Gusev ◽  
P. Yu. Gusev ◽  
I. A. Aksenov
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Cold Working ◽  
Working Method

Recent x-ray diffraction studies of metal fatigue in Japan

1975 ◽  
Vol 10 (1) ◽  
pp. 32-41 ◽  
Author(s):  
K Tanaka
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Fatigue Damage ◽  
Fatigue Cracks ◽  
Stress And Strain ◽  
Metal Fatigue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Future Developments ◽  
Non Destructive

This paper describes results of several recent studies, carried out in Japan, on metal-fatigue problems using X-ray diffraction techniques. The subjects covered are the effect of residual stress on fatigue strength, non-destructive detection of fatigue damage from information supplied by X-ray diffraction, and X-ray microbeam analysis of stress and strain near the tips of fatigue cracks and fracture surfaces. The usefulness of the X-ray approach to fatigue problems is emphasized and possible future developments are suggested.

Metallurgical Problems with Orthopaedic Joint Prostheses

1977 ◽  
Vol 35 ◽  
pp. 288-289
Author(s):  
John P. Jendrzejewski ◽  
Gary G. Paulson
Keyword(s):  
Hip Prosthesis ◽  
Fatigue Cracks ◽  
Skeletal Structure ◽  
Metal Fatigue ◽  
Subsequent Removal ◽  
Prosthetic Devices ◽  
X Ray ◽  
Surgical Implants ◽  
Bending Stresses ◽  
Joint Prostheses

Metallic joint prosthetic devices are used to replace the skeletal structure of the human body which has been destroyed by disease or accident. These surgical implants are intended to remain in place for the rest of the patients' life, but often they fail. Subsequent removal and replacement is both expensive and painful. We have had the opportunity to examine numerous joint prosthetic devices which have fractured in use. The scanning electron microscope and energy dispersive X-ray spectrometer used in conjunction with conventional metallography have proven very useful for these failure analyses.The primary failure mode of joint prostheses is metal fatigue. Shown in Figure 1 is a femoral component of a hip prosthesis which failed in the stem portion. Fractographic analysis reveals that reverse bending stresses initiated fatigue cracks at the distal and proximal portion of the stem as pointed out in Figure 2.

scholarly journals ANALISIS INTENSITAS DAN COVERAGE PROSES SHOT PEENING TERHADAP TEGANGAN SISA DAN KEKERASAN PADUAN AL 7075 T7351

2019 ◽  
Vol 4 (2) ◽  
pp. 116-125
Author(s):  
Agus Fikri ◽  
Rifky Rifky ◽  
Mohammad Yusuf Djeli
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Metal Surfaces ◽  
High Speed ◽  
Cold Working ◽  
Surface Hardness ◽  
Initiation And Propagation ◽  
Al 7075 ◽  
Working Method ◽  
Metal Failure

AbstrakShot peening merupakan metode pengerjaan dingin dengan menumbukkan permukaan logam menggunakan partikel-partikel bulat yang berukuran kecil dan berkecepatan tinggi. Dengan proses shot peening dapat dikurangi inisiasi dan propagasi retak yang menyebabkan terjadinya kegagalan terhadap logam. Tujuan penelitian ini adalah untuk mengetahui pengaruh intensitas dan coverage shot peening terhadap tegangan sisa dan kekerasan pada permukaan Al 7075 T7351. Penelitian dilaksanakan dengan menembakkan permukaan logam dengan intensitas 0,0062 A dan 0,0091 A, serta coverage masing-masing 100% dan 200%, kemudian dilakukan pengujian kekerasan permukaan dan tegangan sisa. Hasil penelitian menunjukkan bahwa shot peening menyebabkan terjadinya perubahan tegangan sisa, yaitu 92,5021 MPa pada keadaan tanpa shot peening menjadi -111,8726 sampai -170,5675 MPa setelah dilakukan dishot peening. Selain itu kekerasan pada permukaan meningkat antara 23,4% sampai dengan 44,7%. Meningkatnya kekerasan menunjukkan bahwa terjadi pengerjaan dingin yang besar pada permukaan logam. Pengaruh pelapisan (coverage) 200% ternyata meningkatkan besarnya tegangan sisa dan kekerasan permukaan walaupun belum melampaui intensitas yang lebih besar. Kata kunci : shot peening, intensitas, coverage, kekerasan permukaan, tegangan sisa AbstractShot peening is a cold working method by striking metal surfaces using small, high-speed and round particles. Shot peening can reduce the initiation and propagation of cracks that cause metal failure. The purpose of this analysis is to determine the effect of shot peening intensity and coverage on residual stress and hardness on the surface of Al 7075 T7351. The research was carried out by firing metal surfaces with intensities of 0.0062 A and 0.0091 A, and coverage of 100% and 200%, respectively, then testing surface hardness and residual stress. The results showed that shot peening caused a residual stress change, which was 92.5021 MPa in the state without shot peening to -111.8726 to -170.5675 MPa after it was shot peening. In addition, surface hardness increased from 23.4% to 44.7%. Increased hardness indicates that there is large cold working on the metal surface. The effect of 200% coverage apparently increases the amount of residual stress and surface hardness even though it has not exceeded the greater intensity. Keywords: shot peening, intensity, coverage, surface hardness, residual stress

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