Sensitivity of Macro- and Micro-Residual Stress States of Steel Surfaces to Thermal Influences Caused by Grinding Burn and Laser Treatments

2013 ◽  
Vol 768-769 ◽  
pp. 412-419
Author(s):  
Bernd Eigenmann ◽  
Antje Zösch ◽  
Martin Seidel
Keyword(s):  
Residual Stress ◽  
Threshold Values ◽  
Materials Properties ◽  
X Ray ◽  
Grinding Burn ◽  
Laser Treatments ◽  
Annealing Effects ◽  
Calibration Samples ◽  
Steel Surfaces ◽  
Stress States

Thermal influences, introduced intentionally or unintentionally do have significant effects on surfaces of steel components. Materials properties are reduced by annealing effects or even re-hardening zones can occur. Grinding, one of the most important technological processes for preci-sion manufacturing of hardened steel components, is an important source of thermal influences to steel surfaces. In pronounced cases, these influences are referred to as grinding burn. They are known as possible reasons for gray stains as well as development of cracks and pittings on heavy-duty gears and on roller bearings. The basic effect of thermal influences on the material is a change of the macro- and micro-residual stress states. Therefore, the knowledge of these residual stress states is of fundamental importance. The paper treats the mechanisms of grinding which can lead to thermal influences. Some characteristic appearances of grinding burn are shown and characterized by X-ray macro- and micro residual stress determinations. It is shown that defined laser treatments can be used to create reproducible thermal influences similar to grinding burn. Their effects are also characterized by X-ray residual stress measurements. The sensitivities of X-ray and metallographical investigations are compared. Defined laser traces are proposed as calibration samples for magnetic and eddy current measurements which allow to determine threshold values for the actual apparatus and measuring problem.

scholarly journals Statistical analysis of the reproducibility of residual stress measurements in cold extruded parts

2021 ◽  
Author(s):  
Fabian Jaeger ◽  
Alessandro Franceschi ◽  
Holger Hoche ◽  
Peter Groche ◽  
Matthias Oechsner
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
X Ray Diffraction ◽  
Forming Process ◽  
X Ray ◽  
Stress States ◽  
Key Aspects

AbstractCold extruded components are characterized by residual stresses, which originate from the experienced manufacturing process. For industrial applications, reproducibility and homogeneity of the final components are key aspects for an optimized quality control. Although striving to obtain identical deformation and surface conditions, fluctuation in the manufacturing parameters and contact shear conditions during the forming process may lead to variations of the spatial residual stress distribution in the final product. This could lead to a dependency of the residual stress measurement results on the relative axial and circumferential position on the sample. An attempt to examine this problem is made by the employment of design of experiments (DoE) methods. A statistical analysis of the residual stress results generated through X-Ray diffraction is performed. Additionally, the ability of cold extrusion processes to generate uniform stress states is analyzed on specimens of austenitic stainless steel 1.4404 and possible correlations with the pre-deformed condition are statistically examined. Moreover, the influence of the coating, consisting of oxalate and a MoS2 based lubricant, on the X-Ray diffraction measurements of the surface is investigated.

Combined Neutron and X-Ray Diffraction Analysis for the Characterization of a Case Hardened Disc

2010 ◽  
Vol 652 ◽  
pp. 37-43 ◽  
Author(s):  
Jeremy Epp ◽  
Thomas Hirsch ◽  
Martin Hunkel ◽  
Robert C. Wimpory
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Diffraction Analysis ◽  
Force Balance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Stress State ◽  
Systematic Uncertainties ◽  
Combined Use ◽  
Stress States

The present work has been executed within the framework of the collaborative research center on Distortion Engineering (SFB 570) in order to evaluate the residual stress state of a disc after carburizing and quenching as well as to validate a simulation procedure. The combined use of X-ray and neutron diffraction analysis provided information about the residual stress states in the whole cross section. However, the stress free lattice spacing d0 for the neutron diffraction experiments is problematic and induces systematic uncertainties in the results and the application of a force balance condition to recalculate d0 might be a solution for improving the reliability of the results. Comparison of experimental results with simulation showed that an overall satisfying agreement is reached but discrepancies are still present.

X-Ray Diffraction Measurements of Residual Stress Induced by Surface Compressing Methods

2012 ◽  
Vol 729 ◽  
pp. 199-204 ◽  
Author(s):  
Dávid Cseh ◽  
Valéria Mertinger
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Surface Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardened Alloy ◽  
Compressive Stresses ◽  
Machine Parts ◽  
Stress States ◽  
Operational Behaviour

Residual stresses have a fundamental effect on the operational behaviour and lifetime of industrial products. The fatigue resistance of machine parts can be increased by introducing residual compressive stresses into the surface region. For certain machine parts especially in the vehicle industry the residual stress is strongly demanded by the quality control. For this reason, measuring the stress accurately is becoming increasingly important. The Almen test, which only gives a qualitative result, is widely used in the industry. Shot peening and rolling are methods which are suitable for creating elastic residual stresses. This paper examines the technologies used by Rába Futómű Nyrt. to increase the lifetime by means of residual stress. We performed analysis of the residual stress of samples shot peened the same way but under different heat treatment states. We compared the residual stress values of burnished and hardened shaft joints, and the residual stress states of gear made of hardened alloy, comparing the carbonized ones to ones which were shot peened under small intensity.

Analysis of X-Ray Diffraction Data for the Characterization of Residual Stress

1991 ◽  
Vol 35 (A) ◽  
pp. 561-569
Author(s):  
Jun S. Park ◽  
James F. Shackelford
Keyword(s):  
Residual Stress ◽  
Elastic Constants ◽  
Diffraction Data ◽  
Stress Gradient ◽  
Bearing Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Angle ◽  
Stress States ◽  
Depth Ranges

AbstractThe analysis of linear dϕψ vs sin2ψ x-ray diffraction data in isotropic single phase materials was investigated for the evaluation of x-ray elastic constants. This study developed an experimental model for estimating x-ray elastic constants based on the analysis of biaxial residual stress states, A ball bearing steel and a 1018 steel weldment were evaluated.In a second study, the measurement of residual stress gradients was evaluated for those depth ranges mat can not be evaluated with a single radiation. This requires various planes and radiation energies to obtain the simultaneous conditions of high diffraction angle and large x-ray penetration depth. The evaluation of the overlapped stress gradient region is illustrated in terms of x-ray energy and diffraction angle for the ease of iron. This analysis is specifically developed for the purpose of stress gradient measurement using synchrotron radiation.

A self-consistent method for X-ray diffraction analysis of multiaxial residual-stress fields in the near-surface region of polycrystalline materials. II. Examples

1999 ◽  
Vol 32 (4) ◽  
pp. 779-787 ◽  
Author(s):  
Ch. Genzel ◽  
M. Broda ◽  
D. Dantz ◽  
W. Reimers
Keyword(s):  
Residual Stress ◽  
Stress Component ◽  
Stress Gradient ◽  
Surface Region ◽  
Evaluation Procedure ◽  
Polycrystalline Materials ◽  
Vector Method ◽  
Near Surface ◽  
X Ray ◽  
Stress States

The application of the formalism for residual-stress gradient evaluation based on the measuring principle of the scattering-vector method, which has been derived in the first paper of this series [Genzel (1999).J. Appl. Cryst.32, 770–778], is demonstrated by practical examples. Depending on the statistical scattering of the experimental data, either biaxial or even triaxial residual-stress states may be analysed; the latter case yields self-consistently the depth profiles of the in-plane stresses, σ11(τ) and σ22(τ), the normal stress component, σ33(τ), as well as the strain-free lattice spacing,d0(hkl). The results obtained by this new evaluation procedure are compared with those obtained by X-ray stress-gradient analysis performed on the basis of the sin2ψ method.

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