Microplastic Limit of Steels as a Means of Fatigue Limit Determination

Gajdoš, Ing. Ľubomír; Šperl, Ing. Martin; Kaiser, Jaroslav; Mentl, V.

doi:10.1016/j.proeng.2013.12.115

Cited by 5 publications

(4 citation statements)

References 4 publications

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“…The grains form locally a fine distribution (5-6 points on the scale of the grain size standardized norms), alternating with areas where the pearlite grains are middling increased (3-4 points on the same scale). These aspects are typical for overheating phenomena, this-one being other argument reporting lower strength characteristics [6][7].…”

Section: Determination Of Hardness Of Steelmentioning

confidence: 99%

Metallurgical Characterization of the Failed Motor Shaft Component from an Electric Surgical Motor used in Orthopedic Surgery

Berbecaru

Ciucă

Predescu

et al. 2015

KEM

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The paper presents the results of research conducted to determine the causes that led to the fracture of a motor shaft component from an electric surgical motor used in orthopedic surgery.The chemical and structural analysis emphasized a structure rich in complex silicate and sulfides inclusions. They form areas of weakness, acting like stress concentrators which induce fatigue shaft breakage. Their high density and non-uniform shape and distribution suggest a non-adequate technology of making and casting of steel, destinated to work in difficult conditions and having an important operational role.

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Section: Determination Of Hardness Of Steelmentioning

confidence: 99%

Metallurgical Characterization of the Failed Motor Shaft Component from an Electric Surgical Motor used in Orthopedic Surgery

Berbecaru

Ciucă

Predescu

et al. 2015

KEM

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“…In [6], it was established that in the case of repeated impact periodic loading of metal samples, local destruction occurs as a result of a certain limit accumulation of microplastic deformations in the surface layer. According to the results obtained in work [7], microplastic deformation is realized even under cyclic stresses that are somewhat lower than the endurance limit of the material, determined on the bases of loading recommended by fatigue standards.…”

Section: Introductionmentioning

confidence: 99%

A methodical approach to determining the damage characteristics of cyclically loaded samples of metal structures

Pysarenko¹,

Voinalovich²,

Maylo³

et al. 2022

Tehnìka ta energetika

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The article deals with an actual task of developing engineering methods for predicting the durability of modern long-life machines should be based on the methodology for determining the degree of fatigue damage to materials and structural elements. In the development of such a methodology, the work proposes to use modern optical and computer tools that allow analyzing the parameters of the deformed surface of metal structure samples and, on this basis, to estimate the residual resource of the metal structure. The purpose of the article was to substantiate a methodical approach for determining the limit state of damage using photometric analysis of the topography of the micro-deformed surface of cyclically loaded metal structure samples. To analyze the fatigue damage characteristics of metals and alloys, an experimental information system was developed based on the method of coherent optical scanning of the deformed surface of metal structure samples with a resolution of 0.2 μm/px. The obtained specklograms of the photodiode matrix, corresponding to the two-dimensional image of the micro-deformed surface of the sample in shades of gray 0-255, were computer analyzed. This made it possible to construct diagrams of the kinetics of the process of accumulation of the amplitude of the deformation microrelief of the surface of the laboratory samples for the studied steels St 45 and St 20. It is shown that the kinetics of speckle brightness obtained in the work by the correlation method, which corresponds to the evolution of the accumulation of fatigue damage on the surface of the studied structural steel samples, is characterized by a nonlinear function, which is consistent with the results of deformation microrelief studies obtained by other methods. The proposed methodology for analyzing the discrete distribution of specklogram brightness can be used to predict the onset of the limit state of a metal structure before failure due to fatigue

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“…As it was shown in [1] a point of deviation from linearity on the increasing branch of the hysteresis loop Lσ can be considered to be the MPL. It corresponds to the state when local stresses around pile ups of dislocations at obstacles, predominantly grain boudaries, start to obstruct magnetic domains in rotation to the direction of tensile macrostress.…”

Section: Introductionmentioning

confidence: 99%

“…This quantity varies with the number of stress cycles much as the MPL. On the basis of the work of Kikuchi et al [2] it was concluded [3] that permeability, and thus electrical impedance and microplastic limit, are influenced by dislocation density.…”

Section: Introductionmentioning

confidence: 99%

Verification of the Trend of MPL Variation in Fatigue by Modern Methods

Gajdoš

Šperl

Frankl

et al. 2014

KEM

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The paper presents experimental results concerning the variation of microplastic limit (MPL) during fatigue as determined by the measurement of changes in inductanceLof specimens made from normalized low-C steel CSN 411375. Some indications have been obtained that MPL varies during fatigue with dislocation density. This was proved by nanoindentation, X-ray diffraction and transmision electron microscopy.

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Microplastic Limit of Steels as a Means of Fatigue Limit Determination

Cited by 5 publications

References 4 publications

Metallurgical Characterization of the Failed Motor Shaft Component from an Electric Surgical Motor used in Orthopedic Surgery

Metallurgical Characterization of the Failed Motor Shaft Component from an Electric Surgical Motor used in Orthopedic Surgery

A methodical approach to determining the damage characteristics of cyclically loaded samples of metal structures

Verification of the Trend of MPL Variation in Fatigue by Modern Methods

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