Analysis and Prediction of Residual Stresses in Nitrided Tool Steel

2011 ◽  
Vol 681 ◽  
pp. 352-357 ◽  
Author(s):  
Bojan Podgornik ◽  
Vojteh Leskovšek ◽  
Miha Kovačič ◽  
Joze Vižintin
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Fatigue Resistance ◽  
Tool Steel ◽  
Plasma Nitriding ◽  
Near Surface ◽  
Stress Evaluation ◽  
Nitriding Time ◽  
Precise Knowledge ◽  
Steel Increase

Plasma nitriding is a thermo-chemical process of high importance for engineering components, which through generation of near-surface compressive residual stresses significantly improves wear and fatigue resistance. A precise knowledge of the level and distribution of residual stresses that exist in surface engineered components is necessary for accurate prediction of a component’s fatigue resistance. However, measurement of residual stress is not always possible, especially in the case of industrial tools and dies. Therefore, other methods for residual stress evaluation and prediction are required by industry. Results of this investigation show that residual stress level and depth in plasma nitrided tool steel increase by nitriding time and temperature. On the other hand, experimental data show that residual steel distribution in plasma nitrided tool steels can be determined on the basis of microhardness depth distribution.

Residual Stress in Bone: A Parametric Study

2008 ◽  
Author(s):  
A. Hizal ◽  
B. Sadasivam ◽  
D. Arola
Keyword(s):  
Residual Stress ◽  
Particle Size ◽  
Residual Stresses ◽  
Material Removal ◽  
Surface Deformation ◽  
Radius Of Curvature ◽  
Near Surface ◽  
Size And Shape ◽  
Air Jet ◽  
Particle Size And Shape

A preliminary study was conducted to evaluate the parametric dependence of the residual stress distributions in bone that result from an abrasive air-jet surface treatment. Specifically, the influence of particle size and shape used in the treatment on the residual stress, propensity of embedding particles and material removal were studied. Rectangular beams of cortical bone were prepared from bovine femurs and treated with aluminum oxide and glass particles with different treatment angles. Residual stresses within the bone were quantified in terms of the radius of curvature of the bone specimens measured before and after the treatments, as well as a function of time to quantify decay in the stress. The sub-surface distribution was also examined using the layer removal technique. Results showed that the particle size and shape could be used to control the amount of material removal and the magnitude of residual stress within the treated surfaces. An increase in size of the glass particles resulted in an increase in the residual stress and a decrease in material removed during the treatment. The magnitude of residual stress ranged from 22 MPa to nearly 44 MPa through modulation of the particle qualities (size and shape). A microscopic examination of the treated surfaces suggests that the residual stresses resulted primarily from near-surface deformation.

scholarly journals Intragranular Residual Stress Evaluation Using the Semi-Destructive FIB-DIC Ring-Core Drilling Method

2014 ◽  
Vol 996 ◽  
pp. 8-13 ◽  
Author(s):  
Alexander J.G. Lunt ◽  
Alexander M. Korsunsky
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Titanium Aluminide ◽  
Ion Beam ◽  
Sample Surface ◽  
Image Correlation ◽  
Near Surface ◽  
Core Drilling ◽  
Drilling Method ◽  
Ring Core

Titanium aluminide (TiAl) is a lightweight intermetallic compound with a range of exceptional mid-to-high temperature mechanical properties. These characteristics have the potential to deliver significant weight savings in aero engine components. However, the relatively low ductility of TiAl requires improved understanding of the relationship between manufacturing processes and residual stresses in order to expand the use of such components in service. Previous studies have suggested that stress determination at high spatial resolution is necessary to achieve better insight. The present paper reports progress beyond the current state-of-the-art towards the identification of the near-surface intragranular residual stress state in cast and ground TiAl at a resolution better than 5μm. The semi-destructive ring-core drilling method using Focused Ion Beam (FIB) and Digital Image Correlation (DIC) was used for in-plane residual stress estimation in ten grains at the sample surface. The nature of the locally observed strain reliefs suggests that tensile residual stresses may have been induced in some grains by the unidirectional grinding process applied to the surface.

Inverse Hole-Drilling Method for Residual Stress Investigation

2016 ◽  
Vol 827 ◽  
pp. 117-120
Author(s):  
Jaroslav Vaclavik ◽  
Stanislav Holy ◽  
Jiří Jankovec ◽  
Petr Jaros ◽  
Otakar Weinberg
Keyword(s):  
Residual Stress ◽  
Numerical Modeling ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Hole Drilling ◽  
Back Side ◽  
Stress Evaluation ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Strain Gauge Rosette

The method for residual stress measurement using through the hole drilling and investigation of the residual stresses relief with the help of incremental layers removing is presented. Drilling the rosette-hole from the opposite side – the inverse layers removing – have to be used for evaluation of residual stress near the back side of the object wall in cases when this surface is inaccessible for any hole-drilling instrument. The strain gauge rosette is installed on the opposite side of the drilled wall and a new mechanical task of incremental layers removal must be solved. The calibration constants for residual stress evaluation of HBM RY21 type rosette for this case were derived using numerical modeling by FEA and its experimental verification.

Local Residual Stress Distribution at the Tooth Root Surface of a Broached Steel Component

2012 ◽  
Vol 706-709 ◽  
pp. 1731-1736 ◽  
Author(s):  
Tobias Strauss ◽  
Harald Meier ◽  
Jens Gibmeier ◽  
Volker Schulze ◽  
Alexander Wanner
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Surface Hardness ◽  
Case Hardening ◽  
Dry Cutting ◽  
Machined Surface ◽  
Near Surface ◽  
Case Hardening Steel

Broaching is an important technique for creating tooth structures in mechanical components. In the present work, the effects of the broaching process on the material state in the near surface region at the root of the tooth was analyzed. The studies were carried out on broached plates made from case hardening steel SAE 5120. The cutting speed and machining condition (cooling lubricant, dry machining) were varied. During broaching with a TiAlN coated tool the cutting forces were monitored. Subsequently, the local residual stresses at the root of the tooth were determined using X-ray diffraction. Further, surface roughness and micro hardness measurements as well as microstructure analysis complement the results. The results indicate that cutting forces have a high influence on the development of the residual stress state at the machined surface whereas no significant effect on changes in surface hardness and microstructure could be observed. Dry cutting with relatively high cutting speeds (≥ 30m/min) result in low cutting forces and hence in high tensile residual stresses in broaching direction.

Inducing Residual Stress in Bone Using Abrasive Air-Jet Surface Treatment

2007 ◽  
Author(s):  
Alpay Hizal ◽  
Balaji Sadasivam ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Surface Treatment ◽  
Structural Changes ◽  
Surface Deformation ◽  
Radius Of Curvature ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Bone Chemistry ◽  
Air Jet

Based on past research, the growth and repair of bone is a function of physical activity (i.e. stresses) and bone chemistry. As such, the rate of recovery of an individual that has undergone total joint arthroplasty could be influenced by the introduction of changes in bone chemistry and “apparent” stress state in the bone that results from the surgical procedures and/or treatments. This preliminary study explored the opportunity for introducing residual stresses in hard tissues using an air-jet surface treatment. Cortical bone was obtained from bovine femurs and treated with an abrasive jet process. The radius of curvature of the bone specimens was estimated before and after treatment and used in estimating the magnitude of surface residual stress. An SEM analysis was also performed to examine structural changes in the bone caused by the surface treatment. Results showed that it is possible to impart residual stress within bone using an air-jet surface treatment. The magnitude of surface residual stress was 16 ± 0.8 MPa. Residual stresses appeared to result from a combination of near-surface deformation and embedded particles.

Residual Stresses, Distortion, and Heat Treatment

2015 ◽  
pp. 487-497
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Heat Treatments ◽  
Stress Evaluation ◽  
Prediction Techniques ◽  
Deformation Gradients

Temperature and deformation gradients developed in the course of manufacturing can have undesired effects on the microstructures along their path; the two most common being residual stress and distortion. This chapter discusses these manufacturing-related problems and how they can be minimized by heat treatments. It also provides information on residual stress evaluation and prediction techniques.

Analytical and Experimental Approach of Residual Stress on Deep-Rolled Crankshafts and Auto-Fretted Diesel Injection Rails. Effect on Fatigue Resistances in Service

2011 ◽  
Vol 681 ◽  
pp. 261-266 ◽  
Author(s):  
H. Michaud ◽  
Jean Michel Sprauel
Keyword(s):  
Residual Stress ◽  
High Pressure ◽  
Residual Stresses ◽  
Analytical Model ◽  
Fatigue Damage ◽  
Fatigue Resistance ◽  
Experimental Approach ◽  
Industrial Process ◽  
Diesel Injection ◽  
Fatigue Criterion

The fatigue resistance of car components such as crankshafts or diesel injection rails is mainly related to fatigue at geometrical singularities. Its understanding requires the simulations of the different steps of the industrial process resulting in residual stresses generation and their evolutions in service. First concerning crankshaft fatigue damage, a complete analytical model of residual stresses generation and shakedown in fatigue is presented. Then a fatigue criterion is established and validated for this application. Finally, for the high pressure diesel injection rail, this approach can be generalized to the holes intersection singularities.

scholarly journals Investigations on Residual Stresses within Hot-Bulk-Formed Components Using Process Simulation and the Contour Method

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 566
Author(s):  
Bernd-Arno Behrens ◽  
Jens Gibmeier ◽  
Kai Brunotte ◽  
Hendrik Wester ◽  
Nicola Simon ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Process Simulation ◽  
Hot Forming ◽  
Contour Method ◽  
Stress Profile ◽  
X Ray Diffraction ◽  
Forming Process ◽  
Near Surface ◽  
X Ray

Residual stresses resulting from hot-forming processes represent an important aspect of a component’s performance and service life. Considering the whole process chain of hot forming, the integrated heat treatment provided by a defined temperature profile during cooling offers a great potential for the targeted adjustment of the desired residual stress state. Finite element (FE) simulation is a powerful tool for virtual process design aimed at generating a beneficial residual stress profile. The validation of these FE models is typically carried out on the basis of individual surface points, as these are accessible through methods like X-ray diffraction, hole-drilling, or the nanoindentation method. However, especially in bulk forming components, it is important to evaluate the quality of the model based on residual stress data from the volume. For these reasons, in this paper, an FE model which was already validated by near surface X-ray diffraction analyses was used to explain the development of residual stresses in a reference hot forming process for different cooling scenarios. Subsequently, the reference process scenarios were experimentally performed, and the resulting residual stress distributions in the cross-section of the bulk specimens were determined by means of the contour method. These data were used to further validate the numerical simulation of the hot forming process, wherein a good agreement between the contour method and process simulation was observed.

Measurement of Near Surface Residual Stresses Using Electric Discharge Wire Machining

1994 ◽  
Vol 116 (1) ◽  
pp. 1-7 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
M. Gremaud ◽  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Electric Discharge ◽  
Theoretical Approach ◽  
Stress Measurement ◽  
Stress Gradient ◽  
Experimental Results ◽  
Residual Stress Measurement ◽  
Near Surface ◽  
Surface Residual Stresses

In previous work it has been shown that near surface residual stresses may be deduced from surface strains produced by making a cut of progressively increasing depth. The process of electric discharge wire machining (EDWM), by providing very narrow cuts, greatly improves the ability of the method to resolve a stress gradient near the surface. However, the EDWM process may also introduce residual stresses. In the present work a model for estimating the influence of EDWM is presented, and a procedure for eliminating its effect on residual stress measurement is developed. Experimental results validate the theoretical approach.

Application of Hole-Drilling Method in Practice

2006 ◽  
Vol 524-525 ◽  
pp. 555-560 ◽  
Author(s):  
Bojan Podgornik ◽  
Joze Vižintin ◽  
Franci Kopač
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Hole Drilling ◽  
Machine Component ◽  
Practical Applications ◽  
Hole Drilling Method ◽  
Precise Knowledge ◽  
Drilling Method ◽  
Proper Design ◽  
Treatment Procedures

Residual stresses can arise in engineering components as part of their manufacturing or can also be introduced deliberately as part of surface treatment procedures. A precise knowledge of the level of residual stresses that exist in engineering components is necessary in analysis and quality control as well as for accurate prediction of components lifetime. Therefore, reliable methods of determining the magnitude and distribution of residual stresses are required in order to quantify their effect and to avoid detrimental failures. On the other hand on-site portable and nonor near non-destructive methods are required for practical use. The hole-drilling method shows a great potential in measuring and evaluating residual stresses in practical applications. This paper presents results and problems on residual stress measurements performed by the holedrilling method on real components, including forming applications of rolling, punching and cutting, and machine component applications of gears and shafts. Presented results clearly indicate the importance of residual stress information for proper design and use of engineering components.

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