scholarly journals Estimation of Cross-Sectional Residual Stress Distributionon Hardened Layer of Carburized Chromium-Molybdenum Steel by Electron Backscattering Diffraction Method

2014 ◽  
Vol 996 ◽  
pp. 556-561
Author(s):  
Yoshihisa Sakaida ◽  
Tomohito Inayama ◽  
Shigeki Yashiro
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Hardened Layer ◽  
Case Depth ◽  
Polished Surface ◽  
Cross Sectional ◽  
Electron Backscattering ◽  
Electron Backscattering Diffraction ◽  
The Cross

A chromiummolybdenum steel composed of 0.20 mass% carbon was used as a starting material. Three kinds of specimens having different case depths were made by carburizing and quenching. Using the scanning electron microscope, the crystallographic information was measured on the cross-sectional hardened layer by EBSD (electron backscattering diffraction) technique. The KAM (kernel average misorientation, Θ) maps were calculated from the carburized surface to the interior below the case depth of each specimen. The area-average, Θmean, of the KAM map was compared to the case depth and the cross-sectional residual stress distribution measured by x-ray. As a result, the area-average of the hardened layer was larger than that of the interior of specimen after quenching. The estimated depth of the increment in the Θmean was found to accord to the case depth and be proportional to the depth in which large compressive residual stress was distributed on the gradually polished surface. Therefore, both the case depth and eigen strain distribution that induce the compressive residual stress are indirectly estimable by electron backscattering diffraction method.

Measuring Strains for Hematite Phase in Sinter Ore by Electron Backscattering Diffraction Method

2006 ◽  
Vol 326-328 ◽  
pp. 237-240 ◽  
Author(s):  
Yasushi Sasaki ◽  
Manabu Iguchi ◽  
Mitsutaka Hino
Keyword(s):  
Linear Relationship ◽  
Strain Gauge ◽  
Diffraction Method ◽  
Local Strain ◽  
Electron Backscattering ◽  
Hematite Phase ◽  
Compression Strain ◽  
Electron Backscattering Diffraction ◽  
Ebsd Technique ◽  
The Relationship

Based on the relationship between quantified blurring degree of Kikuchi bands obtained by an electron backscattering diffraction (EBSD) technique and macroscopic strains measured by a strain gauge, the local compression strain SEBSD in sinter ore has been evaluated under various conditions. There is a good linear relationship between the SEBSD and the strains measured by a strain gauge. The local strain SEBSD evaluated by EBSD patterns can be used as an index of local strains.

scholarly journals Effect of thermal relaxation on residual stress and microstructure in the near-surface layers of dual shot peened Inconel 625

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880053
Author(s):  
Lihong Wu ◽  
Chuanhai Jiang
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Elevated Temperatures ◽  
Thermal Relaxation ◽  
Diffraction Method ◽  
Relaxation Behavior ◽  
Inconel 625 ◽  
Surface Layers ◽  
Near Surface ◽  
Subsurface Layers

Thermal relaxation behavior of residual stress and microstructure in the near-surface layers of dual shot peened Inconel alloy 625 was investigated by X-ray diffraction method. Residual stress on the top surface layer was significantly relaxed in the first 15 min at the elevated temperatures of 500°C, 600°C, and 700°C. However, there was still high maximum compressive residual stress in subsurface layers. The relaxation behavior of residual stress has contributed to the thermally activated process. The activation enthalpy Δ H and m were calculated according to the Zener–Wert–Avrami method, the values of which were 1.59 eV and 0.4934, respectively. Microstructural evaluation revealed that it was slightly changed in the near-surface layers after various isothermal treatments. Accordingly, high level of compressive residual stress and dislocation density resulted in the retained mechanical properties of dual shot peened Inconel 625, which was discussed based on the relaxation of microstructure and microhardness.

Effects of Laser Shock Processing on Corrosion Properties of 304 Stainless Steel

2010 ◽  
Vol 426-427 ◽  
pp. 109-113
Author(s):  
De Jun Kong ◽  
Hong Miao ◽  
A.P. Hu
Keyword(s):  
Aqueous Solution ◽  
Residual Stress ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Compressive Residual Stress ◽  
Hardened Layer ◽  
304 Stainless Steel ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
Corrosion Properties

The surface of 304 stainless steel was processed by laser shock wave, its surface micro-structures were observed with SEM, and residual stresses on its surface were measured with X-ray diffraction (XRD) stress tester, and the production mechanism of residual stress was analyzed. The experiment of stress corrosion in 25% NaCl aqueous solution was finished, the crack sensitivity of stress corrosion in NaCl aqueous solution was researched, and the effects of LSP on stress corrosion resistance were analyzed. The results shown that the refined hardened-layer is acquired on the surface of 304 stainless steel by LSP, and compressive residual stress has greatly increased, which improve availably the performances of stress corrosion resistant. The time of appearing cracks is inverse ratio with compressive residual stress, and LSP decreases effectively its stress corrosion cracks.

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.

Numerical Simulation of Residual Stress Field Induced by Ultrasonic Shot Peening

2008 ◽  
Vol 373-374 ◽  
pp. 832-835 ◽  
Author(s):  
Gang Ma ◽  
Xiang Ling ◽  
Yuan Song Zeng
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Residual Tensile Stress ◽  
Finite Element Software ◽  
Ultrasonic Shot Peening ◽  
Stress Layer

A 3D finite element model is established to simulate the ultrasonic shot peening process by using a finite element software ABAQUS. The residual stress distribution of the AISI 304 stainless steel induced by ultrasonic shot peening (USP) is predicted by finite element analysis. Ultrasonic shot peening (USP) process can cause a compressive residual stress layer on the surface of the material. During the simulation, many factors, e.g., ultrasonic shot peening duration, initial residual stress, hourglass, etc., are taken into consideration for the purpose of optimizing the process. The simulation results show that ultrasonic shot peening can produce a compressive residual stress layer on the surface of the material even if there is initial residual tensile stress (250MPa) and the longer peening duration. The residual stress of simulation were compared with the experiment data which were obtained under the same ultrasonic shot peening parameters and have a good agreement with the measurement values by X-ray diffraction method. In conclusion, ultrasonic shot peening is an effective method for protecting weldments against stress corrosion cracking by introducing the compressive residual stress layer into the surface of stainless steel.

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.

Sign in / Sign up

Export Citation Format

Share Document