Ultrasonic Evaluation of Compressive Residual Stress of Surface Treated Metals

Shot peening is an effective method of improving fatigue performance of machine parts in the industry by producing a thin surface layer of compressive residual stresses that prevents crack initiation and retards crack growth during service. Nondestructive evaluation of the prevailing compressive residual stresses in the shallow subsurface layer is realized by the critically refracted longitudinal (Lcr) waves. This paper presents experimental data obtained on SMAT (surface mechanical attrition treatment) steel alloy S355 sample. Comparative travel-time shows that there are statistically significant differences in treated and untreated specimen. With knowledge of the acoustoelastic constants which are obtained by a test calibration, the experimental data indicates that compressive residual stresses are distributed near subsurface (hundreds of micron). These stress results show that the Lcr technique is efficient for evaluation of residual stresses after the surface treatment.

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Determination of Compressive Residual Stresses Using Critically Refracted Longitudinal (Lcr) Waves

Recent Advances in Nondestructive Evaluation Techniques for Material Science and Industries ◽

10.1115/pvp2004-2827 ◽

2004 ◽

Cited By ~ 1

Author(s):

Farid Belahcene ◽

Jian Lu ◽

Fabien Thomas ◽

Xiaolai Zhou

Keyword(s):

Residual Stresses ◽

Subsurface Layer ◽

Steel Sample ◽

Surface Mechanical Attrition Treatment ◽

Velocity Variation ◽

Hole Drilling ◽

Ultrasonic Technique ◽

Shallow Subsurface ◽

Hole Drilling Method ◽

Compressive Residual Stresses

Surface treatment methods are widely used in the aerospace industry to increase the metal parts damage tolerance by producing a thin surface layer of compressive residual stresses that prevents crack initiation and retards crack growth during service. Nondestructive evaluation of the prevailing compressive residual stresses in the shallow subsurface layer is realized by the ultrasonic technique. The method is based on the measurement of ultrasonic wave velocity variation versus the stress state variation. The application of the Lcr technique (using longitudinal critically refracted wave) has been performed on the SMAT (surface mechanical attrition treatment) steel sample, for which the residual stresses are determined in different zones and depths. The results show that the ultrasonic technique is rather efficient for the evaluation of residual stresses and control of the state of the material after mechanical treatment. The experimental results are successfully compared with the hole drilling method.

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A dislocation density–based comparative study of grain refinement, residual stresses, and surface roughness induced by shot peening and surface mechanical attrition treatment

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-020-05413-8 ◽

2020 ◽

Vol 108 (1-2) ◽

pp. 505-525 ◽

Cited By ~ 2

Author(s):

Cheng Wang ◽

Chuanli Wang ◽

Long Wang ◽

Yongbin Lai ◽

Kun Li ◽

...

Keyword(s):

Surface Roughness ◽

Dislocation Density ◽

Residual Stresses ◽

Comparative Study ◽

Grain Refinement ◽

Shot Peening ◽

Surface Mechanical Attrition Treatment ◽

Mechanical Attrition

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Interface Diffusion in Cu Processed by Means of Surface Mechanical Attrition Treatment

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.289-292.557 ◽

2009 ◽

Vol 289-292 ◽

pp. 557-563 ◽

Cited By ~ 2

Author(s):

Z.B. Wang ◽

K. Wang ◽

K. Lu ◽

Gerhard Wilde ◽

Sergiy V. Divinski

Keyword(s):

Grain Size ◽

Surface Layer ◽

Subsurface Layer ◽

Coarse Grained ◽

Surface Mechanical Attrition Treatment ◽

Nanostructured Surface ◽

Radiotracer Technique ◽

Mechanical Attrition ◽

The Difference ◽

Effective Diffusivities

A nanostructured surface layer with a gradient microstructure was produced on a Cu plate by means of the surface mechanical attrition treatment (SMAT). Diffusion of Ni in the nanostructured layer was investigated by the radiotracer technique at temperatures from 383 to 438 K. The measured diffusion profiles consist of two distinct sections with different slopes, the steep one corresponding to the top surface layer with the grain size of 10 to 25 nm and the shallow one corresponding to a subsurface layer with a grain size of 25 to 100 nm. The effective diffusivities derived from both sections are more than 2 orders of magnitudes higher than the grain boundary diffusivities in coarse-grained Cu. The significantly accelerated diffusion rates are expected to be associated with the “non-equilibrium” states of interfaces in the nanostructured surface layer induced by SMAT. The difference between the diffusivities in the top and sub- surface layer might result from the fact that most interfaces developed from twin boundaries in the former while produced by dislocation activities in the latter.

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How to Select Induction Surface Hardening and Finished Grinding Conditions in Order to Ensure High Compressive Residual Stresses on Machine Parts Surface

Materials Science Forum ◽

10.4028/www.scientific.net/msf.404-407.623 ◽

2002 ◽

Vol 404-407 ◽

pp. 623-628 ◽

Cited By ~ 2

Author(s):

Janez Grum

Keyword(s):

Residual Stresses ◽

Surface Hardening ◽

Grinding Conditions ◽

Machine Parts ◽

Induction Surface Hardening ◽

Compressive Residual Stresses

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Analysis of residual stresses in main crankshaft bearings after induction surface hardening and finish grinding

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/09544070360550282 ◽

2003 ◽

Vol 217 (3) ◽

pp. 173-182 ◽

Cited By ~ 18

Author(s):

J Grum

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Subsurface Layer ◽

Physical And Mechanical Properties ◽

Fatigue Cracking ◽

Correct Selection ◽

Grinding Wheel ◽

Process Conditions ◽

Workpiece Material ◽

Compressive Residual Stresses

The exact pattern of residual stresses will depend on the heat treatment temperatures employed, the depth of hardening and the type of quenchant. Process conditions that give rise to compressive residual stresses on the surface of heat-treated components are favourable. This type of residual stress delays the initiation of fatigue cracking in service, which typically occurs on the surface of the part under the action of cyclic tensile stresses. The last phase in the manufacturing of crankshafts is finish grinding in order to achieve the desirable condition of the surface and the subsurface layer, i.e. suitable dimensions, suitable surface roughness and the corresponding distribution of relative grinding residual stress in the subsurface have to be ensured. By correct selection of the grinding wheel and grinding conditions, taking into account the physical and mechanical properties of the workpiece material, the very favourable compressive residual stresses in the hardened surface layer will be retained after grinding.

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Comparison between Conventional Shot Peening (SP) and Surface Mechanical Attrition Treatment (SMAT) on a Titanium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.996.964 ◽

2014 ◽

Vol 996 ◽

pp. 964-968 ◽

Cited By ~ 5

Author(s):

Donaro Gallitelli ◽

Delphine Retraint ◽

Emmanuelle Rouhaud

Keyword(s):

Experimental Data ◽

Residual Stress ◽

Titanium Alloy ◽

Shot Peening ◽

Surface Characteristics ◽

Surface Mechanical Attrition Treatment ◽

Mechanical Attrition ◽

Stress Profiles ◽

Stress States ◽

Analytical Approaches

In this paper the residual stress states induced by conventional shot peening (SP) and surface mechanical attrition treatment (SMAT) are compared. The treated part correspond to plates made of a titanium alloy. Different intensities of these two mechanical treatments are first considered: their influence on the surface characteristics (roughness, hardness...) is studied. These experimental data are then used to develop a model for the residual stress profiles with dimensional analysis, Experimental and analytical approaches are then discussed.

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Generation of Nanostructures on 316L Stainless Steel and Its Effect on Mechanical Behavior

Materials Science Forum ◽

10.4028/www.scientific.net/msf.490-491.625 ◽

2005 ◽

Vol 490-491 ◽

pp. 625-630 ◽

Cited By ~ 15

Author(s):

T. Roland ◽

Delphine Retraint ◽

K. Lu ◽

Jian Lu

Keyword(s):

Residual Stress ◽

Mechanical Behavior ◽

316L Stainless Steel ◽

Mechanical Response ◽

High Strength ◽

Nanostructured Material ◽

Surface Mechanical Attrition Treatment ◽

Metallic Materials ◽

Mechanical Attrition ◽

Compressive Residual Stresses

Improved mechanical behavior of surface nanostructured metallic materials produced by means of a surface mechanical attrition treatment (S.M.A.T) is investigated experimentally. Based on microscopic observations and residual stress measurements, factors leading to the high strength and yielding are discussed. The effects due to treatment, as compressive residual stresses, are in that way studied for a better understanding of their influence on the global mechanical response of the nanostructured material. In regards of this, a simple way to increase the ductility of such a nanostructured material is also presented.

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