scholarly journals Precision of the Residual Stress determined by X-ray Diffraction: Summery and Limits

2019 ◽  
Author(s):  
Eckehard Mueller
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Round Robin ◽  
Surface Treatments ◽  
X Ray Diffraction ◽  
Measurement Standard ◽  
Passenger Cars ◽  
Round Robin Test ◽  
X Ray ◽  
Mechanical Surface

Today components specially for passenger cars are weight optimized. Often it is done by mechanical surface treatments. Therefore, the amount of compressive residual stress induced by the treatment must be known. The measurement is very often done by x-ray diffraction. But how precise can you determine (and not directly measured) the amount? A big question is the calibration of the equipment. A specimen must be designed and calibrated by round robin test, because no measurement standard is available.

Characteristics of Residual Stress in P92 Steel Welds

2007 ◽  
Vol 26-28 ◽  
pp. 1175-1180
Author(s):  
Keun Bong Yoo ◽  
Hyun Sun Choi ◽  
Eui Hyun Kim ◽  
Jae Hoon Kim
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Welding Residual Stress ◽  
Distribution Characteristics ◽  
X Ray Diffraction ◽  
P92 Steel ◽  
X Ray ◽  
Steel Welds ◽  
Directional Difference

Welding residual stress has important influence on the performance of engineering components. In this paper, the residual stress and FWHM were measured by X-ray diffraction method to investigate characteristics for P92 steel welds. The aim of the study is to estimate the residual stress and FWHM distribution characteristics. A compressive residual stress distributed as a function of depth has a different pattern in welds and base metal. A large tensile residual stress occurs welds and near the HAZ, but approaches gradually zero as away from the welding center. Residual stress and FWHM undergo rapid relaxation after PWHT. Also, FWHM is a scalar quantity without any directional difference and is proportional to hardness on the whole.

Modification of Microstrucure and Residual Stress on Friction Welding Surface of Titanium Alloy by Water-Jet Cavitation Peening

2011 ◽  
Vol 317-319 ◽  
pp. 429-435 ◽  
Author(s):  
Dong Ying Ju ◽  
Xin Mao Fu ◽  
Shun Na ◽  
Bing Han ◽  
Xiao Hu Deng
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Water Jet ◽  
X Ray Diffraction ◽  
X Ray ◽  
Welding Surface ◽  
Scanning Electron

Water jet cavitation peening is applied to improve the strength and mechanical properties of the friction-welded joints of titanium alloys. Scanning electron microscopy observations of the microstructure of the welded joints and welded area before/after water jet cavitation peening confirm slip dislocation at the microstructure near the surface of the specimens. The residual stress on the surface of the welded joint is measured by X-ray diffraction. The results indicate the effect of peening time on the strength of compressive residual stress.

Shakedown During Fatigue of Residual Stresses Introduced by Different Mechanical Surface Treatments

2006 ◽  
Author(s):  
Christopher M. Gill ◽  
Philip J. Withers ◽  
Alex Evans ◽  
Neil Fox ◽  
Koichi Akita
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Glass Bead ◽  
Compressive Residual Stress ◽  
Cold Work ◽  
Diffraction Method ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cold Worked

A layer of compressive residual stress extending from the surface of a component can help to extend fatigue life, but it must remain stable during applied service loading. Metal shot and glass bead peening are traditionally used; introducing a shallow (100–300μm) layer of compressive residual stress and a highly cold worked surface. Laser peening and deep rolling are capable of introducing much deeper compressive residual stresses combined with lower levels of cold work. In this paper we report on the level of shakedown of residual stress brought about by constant strain amplitude fatigue. Glass and metal shot peened, laser peened and deep rolled Ti-6Al-4V samples have been studied. The residual stress profiles as a function of depth have been measured using neutron diffraction, laboratory x-ray diffraction and a hybrid hole-drilling/laboratory x-ray diffraction method. The magnitude and depth of cold work determined for each of the treatment methods. The extent of subsequent residual stress shakedown under different strain amplitudes and load ratios, in deep rolled, glass bead and metal shot peened samples is also assessed.

scholarly journals Determination of phases and residual stresses after martensitic transformation induced by rolling in 304L stainless steel

2019 ◽  
Vol 24 (3) ◽  
Author(s):  
Juciane Maria Alves ◽  
Luiz Paulo Brandao ◽  
Andersan dos Santos Paula
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Martensitic Transformation ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Sample Thickness ◽  
304L Stainless Steel ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACT The 304L austenitic stainless steel is susceptible to deformation induced martensitic transformation. This phase transformation depends on the temperature as well as on the mode, rate and level of deformation. In this work the phases and residual stresses of a 304L TRIP steel where martensitic transformation was induced by cold rolling were investigated by X-ray diffraction XRD. The analyses were performed for different sample thicknesses. The results showed that the phase composition and the residual stresses are strongly dependent on sample thickness. All samples showed a compressive residual stress.

A Study on Fatigue Crack Propagation Properties Using the X-Ray Diffraction Method

2008 ◽  
Vol 575-578 ◽  
pp. 1162-1169
Author(s):  
Md. Anowar Hossian ◽  
Man Bae Lim ◽  
Sun Chul Huh ◽  
Won Jo Park
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Stress Effect ◽  
X Ray Diffraction ◽  
X Ray

This study evaluated fatigue crack growth characteristics, Besides consider compressive residual stress effect and verified the most suitable shot peening velocity. Fatigue crack growth delay effect was compressive residual stress, but over peening did action projecting velocity that accelerate fatigue crack growth rate. X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. Fracture mechanics parameters could be estimated by the measurement of X-ray parameters, and the fractography observation was performed using a scanning electron microscope (SEM) for fatigue fracture surface. As the shot peening velocity increases, striation width increased. The changes in X-ray material parameters described above are directly related to the process of fatigue until the initiation of fatigue crack and X-ray diffraction pattern is thought that failure prediction with stress distribution is possible.

scholarly journals Recommendations for the measurement of residual stresses in welded joints by means of X-ray diffraction—results of the WG6-RR test

2020 ◽  
Author(s):  
Th. Nitschke-Pagel
Keyword(s):  
Residual Stresses ◽  
Boundary Conditions ◽  
Welded Joints ◽  
High Reliability ◽  
Measurement Techniques ◽  
Round Robin ◽  
X Ray Diffraction ◽  
Round Robin Test ◽  
X Ray

AbstractResidual stresses in welded joints are often of extended interest in order to evaluate unexpected failures or distortions. Since the possibilities to calculate residual stresses in welds are still strongly limited, the measurement techniques are still of great importance. Several measurement techniques with particular possibilities and limitations are available today where especially the different diffraction methods are used mostly. The material, weld type, and the size of the components are important for the quality of the results obtained with different methods as well as the environment where the measurements have to be carried out. The paper shall give an overview of the results of a round robin test on the application of XRD on butt welded joints which has been carried out in cooperation of different experienced laboratories. The results show the high reliability of XRD measurements in welds, if the measurements are performed under well-defined boundary conditions. The experiences can be used as a recommendation about useful measurement conditions the expectable quality of the results.

Relationship between Compressive Residual Stress Relaxation and Microhardness Reduction after Cyclic Loads on Shotpeened ASTM A516 Grade 70 Steel

2018 ◽  
Vol 765 ◽  
pp. 232-236 ◽  
Author(s):  
Mohd Rashdan Isa ◽  
Omar Suliman Zaroog ◽  
Fareg S. Ali
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Shot Peening ◽  
Cyclic Load ◽  
Compressive Residual Stress ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Load ◽  
Hardness Values

Shot peening process is a cold performed function to enhance the mechanical properties which is widely used in many industries. This process introduces compressive residual stress which was proven to increase the fatigue life, geometry stability and corrosion resistance. However, the benefit of the residual stress is still unstable due to the relaxation during the operation. This paper will study on the trend of the relaxation of residual stress against cyclic loading as well as the change in the hardness. The material used in this study is carbon steel ASTM A516/ SA 516 Grade 70. Shot peening process with steel shots was applied to the samples to introduce compressive residual stress in the samples. Cyclic load was applied to samples after shot peening process with low load of 52Mpa (20% of Yield Strength) and high load of 208Mpa (80% of Yield Strength). The measurement of residual stress using X-Ray diffraction and hardness test was done on the samples to study the trend of the relaxation of residual stress and the change in hardness values. The result shows that more relaxation of residual stress occurs if the applied cyclic load is higher. The change of hardness trend is found non-sequenced in this study due to random coverage of shot peening.

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