Prediction and Measurement of Residual Stresses Arising From Quenching of Stainless Steels

2004 ◽  
Author(s):  
S. Hossain ◽  
C. E. Truman ◽  
D. J. Smith ◽  
M. R. Daymond
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Stainless Steels ◽  
Numerical Study ◽  
Hole Drilling ◽  
The Core ◽  
Residual Stress State ◽  
Surface Residual Stresses ◽  
Compressive Residual Stresses ◽  
Good Agreement

This paper presents results from an experimental and numerical study examining the creation of highly triaxial residual stresses in stainless steel. This was motivated by a need to model and understand creep in aged power plant. The residual stresses were introduced by rapid spray water quenching of heated solid stainless steel spheres and cylinders. Finite element (FE) simulations predicted high compressive residual stresses around the surface of the specimens and tensile residual stresses near the centre. Surface residual stresses were measured using the incremental centre-hole drilling (ICHD) technique. Neutron diffraction (ND) was used to measure the interior residual stresses. The measurements were in good agreement with FE predictions. The ND measurements confirmed that a highly triaxial residual stress state existed in the core of the specimens.

The Compliance Method for Measurement of Near Surface Residual Stresses—Application and Validation for Surface Treatment by Laser and Shot-Peening

1994 ◽  
Vol 116 (4) ◽  
pp. 556-560 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
M. Gremaud ◽  
A. Rosselet ◽  
R. D. Streit
Keyword(s):  
Residual Stresses ◽  
Surface Treatment ◽  
Hole Drilling ◽  
Ray Method ◽  
Near Surface ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Surface Residual Stresses ◽  
Ray Methods ◽  
Good Agreement

Residual stresses due to surface treatment are measured using the compliance method. The method makes use of the strains measured on the surface while a cut is extended progressively along a plane of interest. The experimental results for a shot peened specimen show good agreement with those obtained by the X-ray method. This experiment demonstrates that the compliance method is accurate and capable of measuring residual stresses which vary rapidly over a depth of less than 50 μm. Good general agreement with results by the X-ray method is also obtained for a laser treated specimen. Some advantages and disadvantages of the present method relative to hole-drilling, layer removal and X-ray methods are discussed.

scholarly journals Analysis of Residual Stress in Stress Harps of Grey Iron by Experiment and Simulation

2014 ◽  
Vol 996 ◽  
pp. 586-591 ◽  
Author(s):  
Pål Schmidt ◽  
Lin Peng Ru ◽  
Vadim Davydov ◽  
Mattias Lundberg ◽  
Maqsood Ahmad ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Casting Process ◽  
Axial Direction ◽  
Hole Drilling ◽  
Fe Simulations ◽  
Stress Relieving ◽  
Compressive Residual Stresses ◽  
Good Agreement ◽  
Grey Iron

Stress harps with bars of different size were used to study residual stresses due to different cooling rate during casting of a grey iron. Finite element (FE) simulations were performed to predict residual stresses from the casting process and the effect of a stress relieving heat treatment. Intended for validating the simulations, neutron diffraction (ND) and hole drilling methods were used to measure the residual stress distribution through the thickness and in a thin surface layer, respectively. Good agreement between the FE simulations and ND measurements is observed for the annealed harp and the normal and transverse directions of the as cast harp. Discrepancy occurs in the axial direction and especially in the side bars of the as cast harp for which the simulation shows much higher compressive residual stresses. The observed difference between the different techniques was discussed with respect to the characteristics of the different methods.

Influence of Milling Parameters on Surface Residual Stresses of 7050-T7451 Aluminum Alloy

2012 ◽  
Vol 723 ◽  
pp. 208-213 ◽  
Author(s):  
Yi Wan ◽  
Chen Li ◽  
Zhan Qiang Liu ◽  
Shu Feng Sun
Keyword(s):  
Aluminum Alloy ◽  
Residual Stresses ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Orthogonal Direction ◽  
Mechanical Coupling ◽  
Surface Residual Stresses ◽  
Compressive Residual Stresses

Residual stresses generated in milling process affect the performance of machined components. Milling residual stresses correlate closely with the cutting parameters. In this paper, the generation and distribution of surface residual stresses in milling of aluminum alloy 7050-T7451 was investigated. The cutting speed changes from 300m/min to 3000m/min. In the experiments, the residual stresses on the surface of specimen are detected by X-ray diffraction technique. The result shows that compressive residual stresses are generated when cutting speed is under 500 m/min. In feed and its orthogonal direction, the effect of cutting speed and feed rate on residual stresses is similar. The formation of the residual stresses can be explained by thermo-mechanical coupling effects.

Residual Stresses Prediction for CO2 Laser Butt-Welding of 304-Stainless Steel

2006 ◽  
Vol 3-4 ◽  
pp. 125-130 ◽  
Author(s):  
Khaled Y. Benyounis ◽  
Abdul Ghani Olabi ◽  
M.S.J. Hashmi
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Laser Power ◽  
Travel Speed ◽  
304 Stainless Steel ◽  
Hole Drilling ◽  
Design Matrix ◽  
Butt Welding ◽  
Input Variables

Residual stresses are an integral part of the total stress acting on any component in service. It is important to determine and/or predict the magnitude, nature and direction of the residual stress to estimate the life of important engineering parts, particularly welded components. This work aims to introduce experimental models to predict residual stresses in the heat-affected zone (HAZ). These models specify the effect of laser welding input parameters on maximum residual stress and its direction. The process input variables considered in this study are laser power (1.03 - 1.368 kW), travel speed (26.48 – 68.52 cm/min) and focal point position (- 1 to 0 mm). Laser butt-welding of 304 stainless steel plates of 3 mm thick were investigated using a 1.5 kW CW CO2 Rofin laser as a welding source. Hole-drilling method was employed to measure the magnitude, and direction of the maximum principal stress in and around the HAZ, using a CEA-06- 062UM-120 strain gauge rosette, which allows measurement of the residual stresses close to the weld bead. The experiment was designed based on Response Surface Methodology (RSM). Fifteen different welding conditions plus 5 repeat tests were carried out based on the design matrix. Maximum principal residual stresses and their directions were calculated for the twenty samples. The stepwise regression method was selected using Design-expert software to fit the experimental responses to a second order polynomial. Sequential F test and other adequacy measures were then used to check the models adequacy. The experimental results indicate that the proposed mathematical models could adequately describe the residual stress within the limits of the factors being studied. Using the models developed, the main and interaction effect of the process input variables on the two responses were determined quantitatively and presented graphically. It is observed that the travel speed and laser power are the main factors affecting the behavior of the residual stress. It is recommended to use the models to find the optimal combination of welding conditions that lead to minimum distortion.

Effect of Cutting-Edge Geometry and Workpiece Hardness on Surface Residual Stresses in Finish Hard Turning of AISI 52100 Steel

1999 ◽  
Vol 122 (4) ◽  
pp. 642-649 ◽  
Author(s):  
Jeffrey D. Thiele ◽  
Shreyes N. Melkote ◽  
Roberta A. Peascoe ◽  
Thomas R. Watkins
Keyword(s):  
Residual Stresses ◽  
Hard Turning ◽  
Cutting Edge ◽  
Edge Geometry ◽  
Surface Residual Stresses ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Finish Hard Turning ◽  
Hardness Values ◽  
Compressive Residual Stresses

An experimental investigation was conducted to determine the effects of tool cutting-edge geometry (edge preparation) and workpiece hardness on surface residual stresses for finish hard turning of through-hardened AISI 52100 steel. Polycrystalline cubic boron nitride (PCBN) inserts with representative types of edge geometry including “up-sharp” edges, edge hones, and chamfers were used as the cutting tools in this study. This study shows that tool edge geometry is highly influential with respect to surface residual stresses, which were measured using x-ray diffraction. In general, compressive surface residual stresses in the axial and circumferential directions were generated by large edge hone tools in longitudinal turning operations. Residual stresses in the axial and circumferential directions generated by large edge hone tools are typically more compressive than stresses produced by small edge hone tools. Microstructural analysis shows that thermally-induced phase transformation effects are present at all feeds and workpiece hardness values with the large edge hone tools, and only at high feeds and hardness values with the small edge hone tools. In general, continuous white layers on the workpiece surface correlate with compressive residual stresses, while over-tempered regions correlate with tensile or compressive residual stresses depending on the workpiece hardness. [S1087-1357(00)00304-X]

Measurement of Residual Stresses in the Cold-Rolled Fe-Ni-Mn/Invar Thermo-Bimetallic Plate

2013 ◽  
Vol 768-769 ◽  
pp. 101-106
Author(s):  
Harri Lille ◽  
Jakub Kõo ◽  
Jaak Valgur ◽  
Alexander Ryabchikov ◽  
Renno Reitsnik ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Electrochemical Etching ◽  
Hole Drilling ◽  
Drilling Technique ◽  
Cold Rolled ◽  
Bimetallic Plate ◽  
Compressive Residual Stresses

The paper presents a method for measuring residual stresses in normal thermo-bimetal Fe-Ni-Mn/Invar strips with a thickness of 0.76 mm. For this purpose, a setup was designed which permits to remove layers from a strip substrate by electrochemical etching. Residual stresses in the directions that are longitudinal and transversal to rolling are determined by the curvature method based on the layer growing/removing techniques. As a reference, residual stresses were also determined by hole-drilling technique. Tensile and compressive residual stresses arose both in active and in passive layers and were considerably higher when determined by the hole-drilling technique.

Laser brazing of 321 and 410 stainless steels with AMS 4777 filler metal: Experimental and numerical study

2018 ◽  
Vol 233 (4) ◽  
pp. 1062-1074 ◽  
Author(s):  
Ali Khorram
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Filler Metal ◽  
Volume Fraction ◽  
Numerical Study ◽  
Liquid Fraction ◽  
Laser Source ◽  
Conservation Of Energy ◽  
Joint Clearances

321 and 410 stainless steels were brazed using 400 W pulsed Nd:YAG laser source with AMS 4777 filler metal for various joint clearances. Optical microscopy and scanning electron microscopy were used to study the microstructure of all specimens. Mechanical properties (microhardness and tensile test) of all specimens were evaluated. The wetting, spreading, and flowing of AMS 4777 filler metal on substrates during this process were modeled using finite volume model. The equations of conservation of mass, conservation of momentum, and conservation of energy were solved in FLUENT software for calculating volume fraction and liquid fraction. AMS 4777 filler metal shows excellent wettability on the 321 and 410 stainless steels. The filler metal and specimens mainly consist of nickel solid solution (Ni), chromium boride (CrB), and nickel boride (Ni3B). The average microhardness for specimens in seam is 492 HV. The tensile strength of specimens changes from 200 up to 480 MPa due to various joint clearances. The higher tensile strength of 321 stainless steel specimens in comparison with 410 stainless steel specimens is due to less wetting angle and more spreading width of filler metal. The simulated results show that this model can be used for predicting geometry of joints at various joint clearances.

scholarly journals Effect of Residual Stress on the Mechanical Properties of FSW Joints with SUS409L

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yeong-Seok Lim ◽  
Sang-Hyuk Kim ◽  
Kwang-Jin Lee
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Stress Measurement ◽  
Charpy Impact ◽  
Stir Zone ◽  
Hole Drilling ◽  
Friction Stir ◽  
Compressive Residual Stresses

This study was performed to investigate both the residual stress distribution and the effect of the residual stress formed at the welding region on the mechanical properties of the friction stir welded joints with 409L stainless steel sheets. Residual stress measurement with hole-drilling method; mechanical property evaluation including tensile test, Charpy impact test, and fatigue test; and microstructure observation were conducted. It has got no residual stresses to speak of at the center region of the stir zone because the stored stresses are released in the process of the dynamic recrystallization, while a small quantity of compressive residual stresses is formed at the surface region of the stir zone because of strong compression reaction by the tool shoulder. A considerable amount of compressive residual stresses is formed at the thermomechanical affected zone because of the synergy between the thermal expansion due to the heat conduction from the stir zone and mechanical compression by the tool. The formation of residual stresses shows a similar tendency between the advancing side and the retreating side. Both the mitigation of residual stress in the stir zone and the formation of compressive residual stress in the thermomechanical affected zone contribute to the improvement of the mechanical properties of the friction stir welded joints.

Experimental and numerical study of the longitudinal and transverse residual stresses distribution in the constrained groove pressing process of pure copper sheets

2021 ◽  
pp. 146442072110418
Author(s):  
MH Tavajjohi ◽  
M Honarpisheh
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Numerical Study ◽  
Pure Copper ◽  
Accurate Method ◽  
Contour Method ◽  
Average Error ◽  
Finite Element Software ◽  
Pressing Process ◽  
Good Agreement

In this research, the residual stresses distribution resulting from one of the severe plastic deformation methods called Constrained Groove Pressing in pure copper sheets has been studied experimentally and numerically. For this purpose, after the initial preparation of each sample, the mentioned process is applied to the samples up to three passes. After each pass, the residual stresses in these samples in both directions of their length and width have been measured experimentally. To measure the residual stresses in these samples, the contour method, which is a relatively new, effective, and accurate method in providing a two-dimensional residual stress map, has been used. The results indicate that the residual stresses on the surfaces of the samples are compressive and by moving towards the central layers of them, these stresses are converted into tensile residual stresses. The distribution of residual stresses along the length and width of the samples is reported to be relatively uniform. In another part of this research, numerical simulation of the Constrained Groove Pressing process in ABAQUS finite element software is discussed. In this simulation, Johnson–Cook model is used as a constitutive model. The average error of residual stress distribution between the simulation and contour method was about 18% which shown a good agreement.

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