A Method for Improving Compressive Residual Stress of Small Holes Surface by Water-Jet Cavitation Peening

2009 ◽  
Vol 614 ◽  
pp. 137-142 ◽  
Author(s):  
B. Han ◽  
Dong Ying Ju
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Water Jet ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Stress Zone ◽  
Strengthening Technique ◽  
Small Holes

As a novel surface strengthening technique, Water-jet cavitation peening has been applied to improve the fatigue life by inducing the compressive residual stress in the near surface layer of mechanical components. Compared with conventional shot peening, one advantage of WCP is that the complicated and tiny surface can be peened more easily. In this study, the small holes with various diameters and depths in the SUS304 stainless steel specimens were treated by WCP. In order to estimate its strengthening capability to the small holes, the surface residual stress and the depth distributions in the near surface layer of the small holes were measured by X-ray diffraction method. The experimental results show that WCP can successfully improve the near surface compressive residual stress of small holes. The maximum of surface compressive residual stress of WCP state is up to around –450 MPa. The dept of compressive residual stress zone is up to around 125 μm.

The Influence of Shot Peening Process on the Residual Stress and Microstructure in Deformed Surface Layer of S30432 Austenitic Stainless Steel

2013 ◽  
Vol 768-769 ◽  
pp. 550-556 ◽  
Author(s):  
Ke Zhan ◽  
Chuan Hai Jiang ◽  
Henry Pan
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Layer ◽  
Austenitic Stainless Steel ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Micro Structure ◽  
Near Surface ◽  
Deformed Layer

Shot peening is an important surface treatment which can induce compressive residual stress and refine micro-structure in the deformed surface layer. In this paper, the conventional shot peening, dual shot peening and triple shot peening have been applied to S30432 austenitic stainless steel. The residual stress and micro-structure in the deformed layer were investigated by X-ray diffraction method. The results revealed that a compressive residual stress field was induced in the deformed layer for all shot peening conditions. As the shot peening step increased, the compressive residual stresses increased in near surface layer, and then deceased faster in deeper deformed layer. In terms of microstructure, the domain size increased, while the micro-strain decreased with the depth increasing in the deformed layer. Compare with the effect of three different shot peening method, triple shot peenng is more effective to optimize the compressive residual stress, microstructure and micro-hardness of S30432 austenitic stainless steel.

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.

Use of Cavitating Jet for Introducing Compressive Residual Stress

1999 ◽  
Vol 122 (1) ◽  
pp. 83-89 ◽  
Author(s):  
H. Soyama ◽  
J. D. Park ◽  
M. Saka
Keyword(s):  
Residual Stress ◽  
Exposure Time ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Water Jet ◽  
Material Surface ◽  
Principal Stresses ◽  
Plane Normal ◽  
Cavitating Jet

In an attempt to strengthen the surface of materials, the potential of using a cavitating jet to form compressive residual stress has been investigated. Introducing compressive residual stress to a material surface provides improvement of the fatigue strength and resistance to stress corrosion cracking. In general, cavitation causes damage to hydraulic machinery. However, cavitation impact can be used to form compressive residual stress in the same way as shot peening. In the initial stage, when cavitation erosion progresses, only plastic deformation, without mass loss, takes place on the material surface. Thus, it is possible to form compressive residual stress without any damage by considering the intensity and exposure time of the cavitation attack. Cavitation is also induced by ultrasonic, high-speed water tunnel and high-speed submerged water jet, i.e., a cavitating jet. The great advantage of a cavitating jet is that the jet causes the cavitation wherever the cavitation impact is required. To obtain the optimum condition for the formation of compressive residual stress by using a cavitating jet, the residual stresses on stainless steel (JIS SUS304 and SUS316) and also copper (JIS C1100) have been examined by changing the exposure time of the cavitating jet. The in-plane normal stresses were measured in three different directions on the surface plane using the X-ray diffraction method, allowing for the principal stresses to be calculated. Both of the principal stresses are found changing from tension to compression within a 10 s exposure to the cavitating jet. The compressive residual stress as a result of the cavitating jet was found to be saturated after a certain time, but it starts decreasing, and finally, it approaches zero asymptotically. It could be verified in the present study that it was possible to form compressive residual stress by using a cavitating jet, and the optimum processing time could also be realized. The great difference between the water jet in water and air has also been shown in this regard. [S1087-1357(00)00501-3]

scholarly journals Effect of Cavitation Peening on Fatigue Properties in Friction Stir Welded Aluminum Alloy AA5754

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 59
Author(s):  
Hitoshi Soyama ◽  
Michela Simoncini ◽  
Marcello Cabibbo
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Fatigue Life ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Fatigue Properties ◽  
Surface Residual Stress ◽  
Friction Stir ◽  
Sheet Cavitation ◽  
Lightweight Metals

Friction stir welding (FSW) is an attractive solid-state joining technique for lightweight metals; however, fatigue properties of FSWed metals are lower than those of bulk metals. A novel mechanical surface treatment using cavitation impact, i.e., cavitation peening, can improve fatigue life and strength by introducing compressive residual stress into the FSWed part. To demonstrate the enhancement of fatigue properties of FSWed metal sheet by cavitation peening, aluminum alloy AA5754 sheet jointed by FSW was treated by cavitation peening using cavitating jet in air and water and tested by a plane bending fatigue test. The surface residual stress of the FSWed part was also evaluated by an X-ray diffraction method. It was concluded that the fatigue life and strength of FSWed specimen were improved by cavitation peening. Whereas the fatigue life at σa = 150 MPa of FSWed specimen was about 1/20 of the bulk sheet, cavitation peening was able to extend the fatigue life of the non-peened FSW specimen by 3.6 times by introducing compressive residual stress into the FSWed part. This is the first paper to demonstrate the improvement of fatigue properties of FSWed metallic sheet by cavitation peening.

Improvement of Fatigue Strength by Using Cavitating Jet in Air

2004 ◽  
Author(s):  
Hitoshi Soyama ◽  
Dan Macodiyo
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
High Speed ◽  
Diffraction Method ◽  
Water Jet ◽  
Bubble Collapse ◽  
Surface Residual Stress ◽  
Hydraulic Machinery ◽  
Rotating Bending Fatigue ◽  
Cavitating Jet

Cavitation normally causes severe damage in hydraulic machinery such as pumps and valves. However, the cavitation impacts at the bubble collapse can be used to enhance the surface of metallic materials just as the same way as shot peening. In case of peening using cavitation impact, the cavitation is produced by injecting a high-speed water jet in a water-filled chamber. The authors have already demonstrated the fatigue strength improvement of materials using a high-speed water jet in water. Recently the authors succeeded in producing a cavitating jet in air by injecting a high-speed water jet into a low-speed water jet using a concentric nozzle. Cavitating jet in air can be used to peen parts of plant which cannot peened by the water-filled chamber, thereby impeding the initiation and/or the development of cracks. In this study, in order to demonstrate the improvement of fatigue strength of materials using cavitating jet in air, stainless steel (JIS SUS316L) was peened and the residual stress measured using the X-ray diffraction method. The surface residual stress of non-peened and peened specimen was −68 MPa and −350 MPa, respectively. The fatigue strength of the specimen were then investigated using the rotating bending fatigue test, with a stress ratio of R = −1. The fatigue strength of peened specimen by cavitating jet in air improved by 20% compared with nonpeened specimen.

Investigation of residual stress distribution induced during deep rolling of Ti-6Al-4V alloy

2020 ◽  
Vol 235 (1-2) ◽  
pp. 186-197
Author(s):  
Kunpeng Han ◽  
Dinghua Zhang ◽  
Changfeng Yao ◽  
Liang Tan ◽  
Zheng Zhou ◽  
...  
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Circumferential Direction ◽  
Two Dimensional ◽  
Deep Rolling ◽  
Three Dimensional Model ◽  
Surface Residual Stress ◽  
Near Surface

To clarify the effects of deep rolling parameters on residual stress, two-dimensional and three-dimensional finite element models were developed using the Chaboche hardening model. Both two-dimensional and three-dimensional simulation results were compared with experimental results. The three-dimensional model is more accurate, especially the 90° cut-out model. The maximum errors in the longitudinal and circumferential directions of 90° cut-out are 8.9% and 15.6%, respectively. Compared to 20 MPa, a rolling pressure of 38 MPa results in larger and deeper compressive residual stress in both directions, but lower surface residual stress in the circumferential direction. Compared to 30% overlap, 60% overlap produces larger compressive residual stress in the near surface region in the longitudinal direction and deeper residual stress with lower maximum compressive residual stress in the circumferential direction. The friction coefficient only slightly affects residual stress in the circumferential direction; increasing the rolling speed induces higher near surface residual stress in the circumferential direction. Compared to the HG6 tool, the HG8 tool generates decreasing surface residual stresses and deeper residual stress in both directions. Compared to one pass, two passes significantly increase the residual stress in circumferential direction, but only slightly increase the residual stress in the longitudinal direction.

Investigation on Fatigue Crack Growth Behaviour in S45C Steel by Water Cavitation Peening with Aeration

2007 ◽  
Vol 561-565 ◽  
pp. 2485-2488 ◽  
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Tetsuya Nemoto
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Compressive Residual Stress ◽  
Bubble Collapse ◽  
In Situ Observation ◽  
Crack Growth Behaviour ◽  
Near Surface

Water cavitation peening (WCP) with aeration is a recent promising method in the surface enhancement technique, which can induce compressive residual stress in the near surface of mechanical components by the bubble collapse on the surface of components in the similar way as conventional shot peening. In this paper, the effect of WCP on fatigue crack growth behavior was investigated in single-edge-notched flat tensile specimens of S45C steel. The notched specimens were treated by WCP, and the compressive residual stress distributions in the near surface layer were measured by X-ray diffraction method. The tension-tension (R = Smin/Smax = 0.1, f = 10 Hz) fatigue tests were conducted. A Shimadzu servo-hydraulic fatigue test machine with in-situ observation by JSM-5410LV scanning microscope was used for all testing. Compared with those without WCP treatment, WCP can induce the residual compressive stress in the near surface layer, and delay the fatigue crack initiation, and decrease the rate of fatigue crack growth.

Residual Stress Evaluation Induced by Fatigue Crack in Shot Peened, Notched Specimens

2017 ◽  
Vol 885 ◽  
pp. 280-285
Author(s):  
Dávid Cseh ◽  
Valéria Mertinger ◽  
János Lukács
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Stress Relaxation ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Fatigue Properties ◽  
Operational Parameters ◽  
Surface Residual Stress ◽  
Residual Stress State ◽  
Residual Stress Relaxation

The advantages of applied compressive residual stress on fatigue properties of materials is a well-described topic, but the residual stress state of machine elements can change during application, therefore it is necessary to describe how these changes are related to the operational parameters. So the monitoring of residual stress relaxation gives more details to improve the lifetime. The surface residual stress state evolution of hardened (quenched and tempered), shot peened, 2 side notched quadratic fatigue specimens made of 42CrMO4 steel was investigated nondestructively by X-ray diffraction method. Residual stress state was monitored on the surface with 1 mm spatial resolution in 5 mm environment of the notch. The compressive residual stress relaxation associated the notching and the fatigue test and the reversal of sign of the residual stress (from compression to tension) associated the crack propagation were experimentally showed.

scholarly journals Energy-Dispersive Residual Stress Analysis under Laboratory Conditions: Concept for a New Type of Diffractometer

2014 ◽  
Vol 996 ◽  
pp. 192-196 ◽  
Author(s):  
Alexander Liehr ◽  
Manuela Klaus ◽  
Wolfgang Zinn ◽  
C. Genzel ◽  
Berthold Scholtes
Keyword(s):  
Residual Stress ◽  
Stress Analysis ◽  
Evaluation Method ◽  
Diffraction Method ◽  
Energy Dispersive ◽  
Photon Flux ◽  
Surface Residual Stress ◽  
Near Surface ◽  
Laboratory Conditions ◽  
Residual Stress Analysis

In the past decade energy-dispersive (ED) synchrotron diffraction has evolved into a powerful tool for materials analysis. Recording complete diffraction patterns in rather few different measuring directions allows for depth-resolved analysis not only of the near-surface residual stress state, but also of composition and even texture gradients. However, since the number of synchrotron beamlines dedicated to ED-diffraction is restricted to very few instruments, alternatives have to be found which allow for ED residual stress analysis even under low flux laboratory conditions. In this project we start to establish the scientific basis for a measuring and evaluation method to make the transfer of the ED method to the laboratory dimensions possible, which is adapted to the conditions of much lower photon flux and larger beam divergences of laboratory X-ray sources. In this paper, we present the concept of an ED-diffractometer which is equipped with two detectors to enable simultaneous data acquisition for two orientations of the diffraction vector with respect to the sample reference system. The first constructive and experimental steps are presented and furthermore the possibilities and limitations of the new laboratory method and the advantages of the ED diffraction method to realize short measurement times in order to realize a high resolution of information depth are discussed.

Heat Treatment Effects on Distortion, Residual Stress, and Retained Austenite in Carburized 4320 Steel

2014 ◽  
Vol 783-786 ◽  
pp. 692-697 ◽  
Author(s):  
Andrew Clark ◽  
Randy J. Bowers ◽  
Derek O. Northwood
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Retained Austenite ◽  
Compressive Residual Stress ◽  
Surface Residual Stress ◽  
Depth Profiles ◽  
Size And Shape ◽  
Austenite Content ◽  
Treatment Conditions ◽  
The Difference

The effects of heat treatment on distortion, residual stress, and retained austenite were compared for case-carburized 4320 steel, in both the austempered and quench-and-tempered condition. Navy C-ring samples were used to quantify both size and shape distortions, as well as residual stress. The austempering heat treatment produced less distortion and a higher surface residual stress. Both hoop and axial stresses were measured; the difference between them was less than seven percent in all cases. Depth profiles were obtained for residual stress and retained austenite from representative C-ring samples for the austempered and quench-and-tempered heat treatment conditions. Austempering maintained a compressive residual stress to greater depths than quench-and-tempering. Quench-and-tempering also resulted in lower retained austenite amounts immediately beneath the surface. However, for both heat treatments, the retained austenite content was approximately one percent at depths greater than 0.5 mm.

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