scholarly journals The Relationship between Tensile Strain and Residual Stress of High Strength Dual Phase Steel Sheet

2018 ◽  
Vol 175 ◽  
pp. 01033
Author(s):  
Maoyu Zhao a ◽  
Zhengzheng Meng ◽  
Chunyan Tian ◽  
Ping Li
Keyword(s):  
Residual Stress ◽  
Tensile Strain ◽  
Steel Sheet ◽  
Least Squares Method ◽  
Elastic Recovery ◽  
High Strength ◽  
Surface Residual Stress ◽  
Average Residual ◽  
Forming Condition ◽  
The Relationship

The relation between residual stress and tensile strain is an important factor for evaluating plastic formation grade of steel sheet. The degree of plastic deformation (Δl) and elastic recovery (δ) were obtained by measuring the length of DP600 steel sheet sample under different tensile test conditions, i.e. five tensile strains (ε). Furthermore, the average residual stress value in the surface middle (the diameter of 10 mm) region of above tensile samples was analyzed by x-ray diffraction (XRD) in the crystal plane of (211). By processing the diffraction peak angle (2θ) with half width high method (FWHM), the relationship between sin2(ψ) and diffraction angle is attained by least squares method. On this basis, a mathematical model was established to correlate the tensile strain with the residual stress in the present study. The results show that the residual stress decreases and the elastic recovery increases with the increase of tensile strain (ε≤0.205). The relation between residual stress and tensile strain can be described with an exponential function . Finally, a function of tensile strain, elastic recovery and surface residual stress is established, by which a reasonable forming condition, viz. ε=0.205, δ=2.65 mm is determined for achieving the smallest σψ.

Effects of DLC coating on relaxing surface residual stress of the weld in titanium-bearing high-strength steel

2015 ◽  
Vol 38 (5) ◽  
pp. 645-652
Author(s):  
Chia-Po Hung ◽  
Shu-Ming Wu ◽  
Shing-Hoa Wang ◽  
Jiann-Kuo Wu ◽  
Chien-Min Sung
Keyword(s):  
Residual Stress ◽  
High Strength Steel ◽  
High Strength ◽  
Surface Residual Stress ◽  
Dlc Coating

scholarly journals Comparison of Gradients in Orientation and Stress between Experiment and Simulation

2011 ◽  
Vol 702-703 ◽  
pp. 463-468 ◽  
Author(s):  
Anthony D. Rollett ◽  
Francis Wagner ◽  
Nathalie Allain-Bonasso ◽  
David P. Field ◽  
Ricardo A. Lebensohn
Keyword(s):  
Grain Boundary ◽  
Tensile Strain ◽  
Steel Sheet ◽  
Interstitial Free ◽  
Strongly Correlated ◽  
Kernel Average Misorientation ◽  
Full Field ◽  
Interstitial Free Steel ◽  
Before And After ◽  
The Relationship

We examine the relationship between local gradients in orientation, which are quantified with the Kernel Average Misorientation, and the grain boundary network in an interstitial-free steel sheet, before and after 12% tensile strain. A portion of the unstrained microstructure is used as input to a full-field spectral viscoplastic code that simulates the same deformation. The orientation gradients are concentrated near grain boundaries in both experiments and simulation. Mapping out stress gradients in the simulation suggests that the development of orientation gradients is strongly correlated with such gradients.

scholarly journals Correlation Modeling Between Peening-Induced Hardness, Residual Stress and Roughness in Case-Hardened High Strength Steels

2021 ◽  
Author(s):  
Hsin Shen HO ◽  
Cheng LV ◽  
Yonghui HE ◽  
Erliang ZHANG
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Linear Trend ◽  
Roughness Parameter ◽  
High Strength Steels ◽  
High Strength ◽  
Initial Material ◽  
Material Hardness ◽  
Negative Effect ◽  
The Relationship

The present paper is focused on the investigation of the correlation modeling of hardness and compressive residual stress on the surface and subsurface regions of case-hardened 18CrNiMo7-6 steels subjected to shot peening. The results exhibit that the relationship between hardness and compressive residual stress can reasonably well be approximated by an inverse linear model. The analysis suggests that the slope and y-intercept of the inverse linear trend line can be related to the compressive residual stress level and the initial material hardness, respectively. It is further revealed that the negative effect brought by the peening-induced roughness on the measurement of experimental data computed on the surface can be compensated by performing the normalization using the roughness parameter called the maximum valley height (Sv).

Surface Residual Stress Analysis Based on the Molecular Dynamics on Micro/Nano Scale

2012 ◽  
Vol 426 ◽  
pp. 325-329
Author(s):  
Zhu Ying ◽  
L. Zhou ◽  
D.Y. Gao
Keyword(s):  
Molecular Dynamics ◽  
Residual Stress ◽  
Single Crystal ◽  
Copper Surface ◽  
Reference State ◽  
Dynamics Simulation ◽  
Displacement Curve ◽  
Surface Residual Stress ◽  
Nano Scale ◽  
The Relationship

The molecular dynamics simulation and experimental study of residual stress were carried out on micro/nano scale. The relationship between residual stress and hardness was researched by the simulation for nano-indentation process of single crystal cooper. It was showed that load-displacement curve above reference state when single crystal copper surface exists compressive residual stress,and the existence of tensile residual stress is below reference state. Then the phenomenon was analyzed and gave a reasonable explanation. In addition, the regression analysis of relationship between micro/nano-hardness and residual stress was carried out.

scholarly journals Fatigue Limit of Custom 465 with Surface Strengthening Treatment

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 238 ◽  
Author(s):  
Gang An ◽  
Ren-jing Liu ◽  
Guang-qiang Yin
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Fatigue Limit ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Subsurface Layer ◽  
Micro Hardness ◽  
Surface Residual Stress ◽  
Surface Strengthening ◽  
The Relationship

In order to study the effect of nitriding or shot peening on the surface modification and fatigue properties of martensitic stainless-steel Custom 465, the residual stress and micro-hardness of the strengthened layer are determined by X-ray and micro-hardness tester, respectively. The up-and-down method is used to measure the rotational bending fatigue strength at 1 × 107 cycles, and the fatigue fracture characteristic is observed by scanning electron microscopy. The relationship between surface residual stress and internal fatigue limit of surface strengthening treatment is discussed. Results show that nitriding or shot peening surface strengthening layer forms a certain depth of compressive residual stress, where in the surface compressive residual stress of the nitrided specimens is greater than the shot peened specimens. The micro-hardness of the nitrided or shot peened surface strengthening layer is significantly improved, where in the surface micro-hardness of nitriding specimens are higher than shot peening specimens. The nitriding or shot peening surface strengthening can significantly improve the fatigue limit of Custom 465, wherein the fatigue limits of nitrided and shot peened surface strengthened specimens are 50.09% and 50.66% higher than that of the un-surface strengthened specimens, respectively. That is, the effect of the two strengthening methods on fatigue limit is not very different. The fracture characteristics show that the fatigue crack of the un-surface strengthened specimens originates from the surface, while the fatigue crack of surface strengthened specimens originates from the subsurface layer under the strengthened layer. The relationship between the internal fatigue limit and the surface residual stress of the surface strengthened specimen can be used as a method for predicting the fatigue limit of the surface strengthened specimens.

scholarly journals Experimental Analysis of the Feasibility of Shaving Process Applied for High-Strength Steel Sheets

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Wiriyakorn Phanitwong ◽  
Arkarapon Sontamino ◽  
Sutasn Thipprakmas
Keyword(s):  
High Strength Steel ◽  
Steel Sheet ◽  
High Strength ◽  
Forming Process ◽  
Steel Sheets ◽  
Metal Sheets ◽  
Metal Forming Process ◽  
New Material ◽  
The Relationship ◽  
High Ultimate Strength

In recent years, the engineered materials were developed to improve their mechanical properties. A high-strength steel sheet is one of them, developed to serve the requirement of reducing weight of vehicles. Therefore, as a new material, many researches have been carried out to examine the use of sheet metal forming process applied for high-strength steel sheet. However, the feasibility of shaving process applied for it has not been investigated yet. In the present study, this feasibility was revealed by using experiments on two types of high-strength steel sheets: SAPH 440 and SPFH 590Y (JIS). The relationship between shaved surface feature and shearing clearance of high-strength steel sheets corresponded well with those of their conventional metal sheets. However, due to the high ultimate strength of these materials, it was revealed in this present study that there were not any suitable conditions of shaving process that could be applied to achieve the requirements of smooth cut surface overall material thickness.

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