The Experts below are selected from a list of 8799 Experts worldwide ranked by ideXlab platform
M Guagliano - One of the best experts on this subject based on the ideXlab platform.
-
obtaining tailored surface characteristics by combining shot Peening and electropolishing on 316l stainless steel
Applied Surface Science, 2019Co-Authors: P Lopezruiz, I Fernandezpariente, M Guagliano, M B Garciablanco, G Vara, Sara BagherifardAbstract:Abstract Shot Peening is a well-established surface treatment commonly used to improve mechanical properties of material's surfaces. Studies have shown notable enhancement of fatigue strength, wear, scratch and corrosion resistance and fretting properties as a result of an intensive shot Peening treatment, the so-called severe shot Peening. Nevertheless, this process has some drawbacks including quite high surface roughness and possible embedment of shot residuals at the treated surface, which can have adverse effects depending on the final application. In this paper, electropolishing has been evaluated as a cleaning post-treatment for shot peened surfaces of 316L stainless steel. For this purpose, electropolishing voltage has been varied with the aim of obtaining clean and smoother surfaces without sacrificing the mechanical improvements produced by shot Peening. The treated surfaces have been characterized considering surface roughness, morphology, wettability, residual stresses and microhardness evolution after various shot Peening treatments combined with electropolishing using different parameter set-ups to identify the most promising combinations.
-
nanoscale surface modification of aisi 316l stainless steel by severe shot Peening
Materials & Design, 2016Co-Authors: Sara Bagherifard, Sebastian Slawik, I Fernandezpariente, Christoph Pauly, Frank Mucklich, M GuaglianoAbstract:Abstract Surface nanocrystallization is gaining increased attention due to its high potential of enhancing mechanical functionality and modulating material's interaction with the surrounding environment. Among mechanical approaches, severe shot Peening has recently shown to be a very promising technique for surface grain refinement, considering its efficiency, eco-friendliness, relative low cost and minimum geometrical restrictions. This study evaluates the effect of severe shot Peening on microstructural and mechanical properties of 316L stainless steel, which is widely used in biomedical, food preparation, structural and marine applications. 316 L samples, shot peened with different Peening parameters, were studied in terms of morphological and structural features, defect density, grain size, phase transformation, surface topography, surface wettability, residual stresses and microhardness. The results indicated that severe shot Peening induced near surface grain refinement to nano and sub-micron range and transformed the austenite phase into strain-induced α’- martensite in a layered deformation band structure. Severe shot Peening also induced compressive residual stresses and work hardening in the top surface layer. Surface roughness and surface wettability, both of which favorably contribute to modulating the interaction of material with biological environment, were also notably enhanced by severe shot Peening.
-
experimental assessment and simulation of surface nanocrystallization by severe shot Peening
Acta Materialia, 2015Co-Authors: M Guagliano, S M Hassanigangaraj, Ki Sub Cho, Hyonjee Lee Voigt, Christopher A. SchuhAbstract:Abstract Surface nanocrystallization is an effective approach to bypass the difficulties of synthesizing bulk nanocrystalline material and yet exploit its unique advantages in service. This study uses air blast shot Peening over a wide range of coverage (Peening time), from conventional to severe, to generate nanostructured surface layers on high strength low alloy steel. Electron microscopy observations were carried out to systematically study the degree and the mechanism of grain refinement as the severity of deformation increases. A model linking finite element simulation of severe shot Peening to dislocation density evolution due to the accumulated plastic strain was developed to predict the resultant grain/cell size gradient in the surface layers. The proposed framework establishes a physical connection from processing parameters such as media size, velocity and Peening coverage to the resultant structure, opening the possibility of designing a severe surface Peening process to achieve a desired nanostructure.
-
about the role of residual stresses and surface work hardening on fatigue δkth of a nitrided and shot peened low alloy steel
Surface & Coatings Technology, 2008Co-Authors: Ines Fernandez Pariente, M GuaglianoAbstract:Abstract Nitriding and shot Peening are surface treatments widely used to improve the fatigue strength of mechanical and structural components. Both treatments enhance the mechanical properties of the surface layer of material: nitriding mainly by means of chemical transformations and formation of a very hard case, shot Peening mainly due to compressive residual stress field in the sub-surface layer of material. The combined application of nitriding and shot Peening has not been adequately investigated in literature and the known data do not allow to define a general criterion to assess if and when shot Peening application after nitriding can be useful. In this paper the effect of nitriding plus shot Peening on fatigue strength of a low-alloy steel is investigated by means of experimental tests carried out on specimens containing a micro-hole, acting as a pre-crack. To analyse the role played by shot Peening induced residual stresses, a series of specimens was heat-treated after shot Peening, being the aim the partial removal of residual stresses without strongly modifying the mechanical properties of the surface layer of material. After a critical discussion of the results in terms of residual stress, micro-hardness trend and fatigue strength, an original fracture mechanics based approach is proposed to predict the threshold value of the stress intensity factor of nitrided and shot peened steels. The results are in good agreement with the experimental evidence.
Hitoshi Soyama - One of the best experts on this subject based on the ideXlab platform.
-
comparison between the improvements made to the fatigue strength of stainless steel by cavitation Peening water jet Peening shot Peening and laser Peening
Journal of Materials Processing Technology, 2019Co-Authors: Hitoshi SoyamaAbstract:Abstract In order to make a clear comparison between the various Peening methods used to improve the fatigue strength of stainless steel 316L, the fatigue strength of specimens treated by cavitation Peening, water jet Peening, laser Peening and shot Peening were examined using a plate bending fatigue test. Both cavitation Peening and water jet Peening were carried out using a submerged water jet system, and these are distinguished by the distance from the nozzle to the specimen. A submerged laser Peening system was used for laser Peening. The impact with the surface due to laser cavitation was greater than that due to laser ablation. For each Peening method, the optimum coverage was examined by measuring the fatigue life at constant bending stress. Then, the fatigue strength of specimens treated with the optimum coverage was examined. The fatigue strength of the non-peened specimen was 279 MPa, whereas it was 348 MPa for cavitation Peening, 325 MPa for shot Peening, 303 MPa for laser Peening and 296 MPa for water jet Peening. The fatigue strength of each Peening method was affected by the surface roughness and work hardening.
-
comparison between cavitation Peening and shot Peening for extending the fatigue life of a duralumin plate with a hole
Journal of Materials Processing Technology, 2016Co-Authors: Hitoshi Soyama, Fumio TakeoAbstract:Abstract In order to demonstrate the advantages of cavitation Peening, in which the impact due to cavitation bubbles collapsing is used to mechanically treat a surface, compared with shot Peening, the fatigue lives of peened specimens comprising duralumin plates with open holes were evaluated. In the present experiment, cavitation bubbles were generated by injecting a high speed water jet into a water filled chamber, producing what is known as a cavitating jet. The specimens, which had either a chamfered or rounded edge hole, were treated by cavitation Peening and shot Peening, then tested using a tensile fatigue test. The fatigue life of the shot peened specimen was equal to or less than that of the as machined specimen, whereas cavitation Peening extended the fatigue life. When the cavitating jet was injected in such a way that the cavitation bubbles collapsed at the wall surrounding the hole, the fatigue life at a maximum tensile stress, σ max , of 150 MPa was extended by more than a factor of ten. It was also demonstrated that cavitation Peening introduced compressive residual stress of about 300 MPa into the wall surrounding the hole.
-
Suppression of Fatigue Crack Propagation of Duralumin by Cavitation Peening
The Journal of Engineering, 2015Co-Authors: Hitoshi Soyama, Osamu Takakuwa, Naoki Kumagai, Fumio TakeoAbstract:It was demonstrated in the present paper that cavitation Peening which is one of the mechanical surface modification technique can suppress fatigue crack propagation in duralumin. The impacts produced when cavitation bubble collapses can be utilised for the mechanical surface modification technique in the same way as laser Peening and shot Peening, which is called “cavitation Peening”. Cavitation Peening employing a cavitating jet in water was used to treat the specimen made of duralumin Japanese Industrial Standards JIS A2017-T3. After introducing a notch, fatigue test was conducted by a load-controlled plate bending fatigue tester, which has been originally developed. The fatigue crack propagation behavior was evaluated and the relationship between the fatigue crack propagation rate versus stress intensity factor range was obtained. From the results, the fatigue crack propagation rate was drastically reduced by cavitation Peening and the fatigue life of duralumin plate was extended 4.2 times by cavitation Peening. In addition, the fatigue crack propagation can be suppressed by 88% in the stable crack propagation stage by cavitation Peening.
-
The Use of Cavitation Peening to Increase the Fatigue Strength of Duralumin Plates Containing Fastener Holes
Materials Sciences and Applications, 2014Co-Authors: Hitoshi SoyamaAbstract:An effective method for improving the fatigue life of Duralumin plates with fastener holes, such as those used in the construction of aircraft, is to introduce a compressive residual stress around the fastener holes. Cavitation Peening is a novel Peening method that uses the cavitation impact produced when a high-speed water jet is injected into a water-filled chamber. In this paper, Duralumin plate specimens with holes were treated by cavitation Peening under various conditions, and the fatigue strength of the specimens was determined using a plate bending fatigue test. It was revealed that a compressive residual stress was introduced not only on surfaces perpendicular to the axis of the cavitating jet but also on the walls of holes which were parallel to this. It was found that a 51% improvement in fatigue strength could be achieved by cavitation Peening. Note that this is first report demonstrating an improvement in the fatigue life of Duralumin plates with fastener holes by cavitation Peening.
-
effect of the impact energy of various Peening techniques on the induced plastic deformation region
Journal of Materials Processing Technology, 2012Co-Authors: Shinya Kanou, Osamu Takakuwa, Seetha R Mannava, Dong Qian, Vijay K Vasudevan, Hitoshi SoyamaAbstract:Abstract In order to clarify the relationship between the depth of dimples and the plastically deformed region beneath the surface induced by shot Peening and compare the characteristics of various Peening methods in terms of single impact energy, the plastic deformation regions induced by single impact at various Peening techniques were visualized using Fry's etching method. The relationships between impact energy and both the dimple size and plastic deformation region in the high shot speed range (∼50 m/s) were clarified, and the relationships were found to be different from those in the low speed range (∼25 m/s). The plastic deformation zones induced by cavitation and laser Peening were also studied in order to understand their features. The results showed that the ratio of the plastic deformation region to dimple depth induced by cavitation Peening and laser Peening was more than 3 times larger than that induced by conventional shot Peening, though the plastic deformation volumes induced by cavitation and laser Peening were smaller than that induced by conventional shot Peening.
Chuanhai Jiang - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of the residual stress and microstructure character in saf 2507 duplex stainless steel after multiple shot Peening process
Surface & Coatings Technology, 2018Co-Authors: Ming Chen, Chuanhai Jiang, Chengxi Wang, Lianbo Wang, Zhou Xu, Vincent JiAbstract:Abstract In this study, multiple shot Peening treatment was implemented to the SAF 2507 duplex stainless steel. The residual stress, microstructure and strain-induced transformation in the shot-peened specimens were evaluated by X-ray diffraction line profile analysis. Results pointed out that multiple shot Peening was helpful to develop deep layer of high compressive residual stress with moderate work hardening. After triple shot Peening treatment, a maximum compressive residual stress of −1070.5 MPa (at the surface for austenite) and −910.5 MPa (at 10 μm depth for ferrite) were obtained. The multiple shot Peening is more effective in producing the microstructure refinement than single shot Peening. The depth of the refinement layer with domain size smaller than 100 nm reached to 150 μm in the austenite and 100 μm in the ferrite phase of the dually shot-peened specimen, the maximum magnitudes of which after single shot Peening were 100 μm and 75 μm, correspondingly. The quantitative measurement of stained-induced martensite in the shot-peened samples by X-ray phase analysis revealed that larger amount of α′-martensite formed after multiple shot Peening compared to that of single shot Peening, nearly 31.6% α′-martensite was formed at the impacted surface of triply peened specimen. The results also demonstrated that multiple shot Peening could significantly decrease the surface roughness and help to improve the surface quality.
-
micro structure and surface layer properties of 18crnimo7 6 steel after multistep shot Peening
Materials & Design, 2013Co-Authors: Peng Fu, K Zhan, Chuanhai JiangAbstract:Abstract The effects of multistep shot Peening on the structure and mechanical properties of 18CrNiMo7-6 steel have been investigated using X-ray diffraction line profile analysis. X-ray diffraction data reveals the phase transformation from austenite to martensitic phase after SP treatments. The results show that multistep shot Peening can more significantly improve the mechanical properties. The optimal Peening intensity of 0.50 + 0.30 + 0.15 mmA is found for 18CrNiMo7-6 steel. With the optimized shot Peening treatment, the maximum compressive residual stress (located at the depth of 20 μm for martensite) and top-surface compressive residual stress of martensite attain the values of 1463 and 1256 MPa, respectively; While those of austenite are 1039 and 766 MPa, respectively. The domain size of 18CrNiMo7-6 steel decreases to 11.1 nm on the top surface after shot Peening with the intensity of 0.50 + 0.30 + 0.15 mmA, and the micro-hardness on the top surface attains the peak value of 1175 HV.
-
uniformity of residual stress distribution on the surface of s30432 austenitic stainless steel by different shot Peening processes
Materials Letters, 2013Co-Authors: K Zhan, Chuanhai Jiang, Vincent JiAbstract:Abstract Compressive residual stress induced by shot Peening can effectively improve the fatigue resistance of the treated component. Much attention has been paid to increase the compressive residual stress value, and the uniformity of residual stress distribution was often ignored, which was also very important for improving the fatigue resistance. In this paper, the uniformity of compressive residual stress distributions on the surface of S30432 austenitic stainless steel after three different shot Peening treatments has been investigated by X-ray diffraction method. The results revealed that compared with traditional shot Peening, multi-step shot Peening (dual shot Peening, triple shot Peening) methods can not only increase the stress value but also make the stress distribution more uniform.
-
effect of prestress state on surface layer characteristic of s30432 austenitic stainless steel in shot Peening process
Materials & Design, 2012Co-Authors: K Zhan, Chuanhai JiangAbstract:Residual stress and microstructure on surface deformed layer of S30432 austenitic stainless steel after shot Peening with different prestress states were investigated. The domain size and micro-strain in the deformed layer were analyzed by Voigt method. The results showed that the compressive residual stress and microstructure were improved significantly after stress shot Peening. The values of compressive residual stress depended on both the prestress state and the measurement directions. Microstructure investigations revealed that smaller domain size and higher micro-strain were induced compared with the conventional shot Peening. And the variations of microstructure were mainly influenced by the values of prestress state. Based on these investigations, it is concluded that stress shot Peening is superior to conventional shot Peening and it is an effective method to improve the surface properties of S30432 austenitic stainless steel.
-
surface layer characteristics of s30432 austenite stainless steel after shot Peening
Materials Transactions, 2012Co-Authors: K Zhan, Chuanhai Jiang, X Y Wu, Vincent JiAbstract:Three types of shot Peening treatments were applied to S30432 stainless steel. The effect of shot Peening intensity and shot Peening method on the residual stress and microstructure has been investigated. The domain size and micro-strain evolutions in near surface layer were characterized systematically via Voigt method. The results reveal that shot Peening could induce compressive residual stress in the deformed layer for all shot Peening conditions. As the shot Peening step and intensity increase, the compressive residual stresses increase in near surface layer, and decease faster in deeper deformed layer. In the deformed layer, the domain size increases, while the micro-strain decreases with the depth increasing. Comparing with the micro-hardness after shot Peening, it is concluded that increasing the shot Peening step is a considerable way to improve the shot Peening effect. [doi:10.2320/matertrans.M2011390]
Vincent Ji - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of the residual stress and microstructure character in saf 2507 duplex stainless steel after multiple shot Peening process
Surface & Coatings Technology, 2018Co-Authors: Ming Chen, Chuanhai Jiang, Chengxi Wang, Lianbo Wang, Zhou Xu, Vincent JiAbstract:Abstract In this study, multiple shot Peening treatment was implemented to the SAF 2507 duplex stainless steel. The residual stress, microstructure and strain-induced transformation in the shot-peened specimens were evaluated by X-ray diffraction line profile analysis. Results pointed out that multiple shot Peening was helpful to develop deep layer of high compressive residual stress with moderate work hardening. After triple shot Peening treatment, a maximum compressive residual stress of −1070.5 MPa (at the surface for austenite) and −910.5 MPa (at 10 μm depth for ferrite) were obtained. The multiple shot Peening is more effective in producing the microstructure refinement than single shot Peening. The depth of the refinement layer with domain size smaller than 100 nm reached to 150 μm in the austenite and 100 μm in the ferrite phase of the dually shot-peened specimen, the maximum magnitudes of which after single shot Peening were 100 μm and 75 μm, correspondingly. The quantitative measurement of stained-induced martensite in the shot-peened samples by X-ray phase analysis revealed that larger amount of α′-martensite formed after multiple shot Peening compared to that of single shot Peening, nearly 31.6% α′-martensite was formed at the impacted surface of triply peened specimen. The results also demonstrated that multiple shot Peening could significantly decrease the surface roughness and help to improve the surface quality.
-
uniformity of residual stress distribution on the surface of s30432 austenitic stainless steel by different shot Peening processes
Materials Letters, 2013Co-Authors: K Zhan, Chuanhai Jiang, Vincent JiAbstract:Abstract Compressive residual stress induced by shot Peening can effectively improve the fatigue resistance of the treated component. Much attention has been paid to increase the compressive residual stress value, and the uniformity of residual stress distribution was often ignored, which was also very important for improving the fatigue resistance. In this paper, the uniformity of compressive residual stress distributions on the surface of S30432 austenitic stainless steel after three different shot Peening treatments has been investigated by X-ray diffraction method. The results revealed that compared with traditional shot Peening, multi-step shot Peening (dual shot Peening, triple shot Peening) methods can not only increase the stress value but also make the stress distribution more uniform.
-
surface layer characteristics of s30432 austenite stainless steel after shot Peening
Materials Transactions, 2012Co-Authors: K Zhan, Chuanhai Jiang, X Y Wu, Vincent JiAbstract:Three types of shot Peening treatments were applied to S30432 stainless steel. The effect of shot Peening intensity and shot Peening method on the residual stress and microstructure has been investigated. The domain size and micro-strain evolutions in near surface layer were characterized systematically via Voigt method. The results reveal that shot Peening could induce compressive residual stress in the deformed layer for all shot Peening conditions. As the shot Peening step and intensity increase, the compressive residual stresses increase in near surface layer, and decease faster in deeper deformed layer. In the deformed layer, the domain size increases, while the micro-strain decreases with the depth increasing. Comparing with the micro-hardness after shot Peening, it is concluded that increasing the shot Peening step is a considerable way to improve the shot Peening effect. [doi:10.2320/matertrans.M2011390]
-
influence of shot Peening on the fatigue life of laser hardened 17 4ph steel
International Journal of Fatigue, 2011Co-Authors: Chuanhai Jiang, Yanhua Chen, Vincent JiAbstract:In order to improve the fatigue life of 17-4PH steel after laser hardening treatment, shot Peening and dual shot Peening treatments were performed on laser hardened 17-4PH steel in this paper. Characteristic changes of the roughness, hardness and residual stress distribution in three typical areas were discussed in order to gain a better understanding about the shot Peening influence on laser hardened material state. Results showed that initial residual stresses had no influence on the finial residual stress distribution in shot Peening influence region after shot Peening treatment. The fatigue life of laser hardened 17-4PH steel increased dramatically after shot Peening treatment.
K Zhan - One of the best experts on this subject based on the ideXlab platform.
-
micro structure and surface layer properties of 18crnimo7 6 steel after multistep shot Peening
Materials & Design, 2013Co-Authors: Peng Fu, K Zhan, Chuanhai JiangAbstract:Abstract The effects of multistep shot Peening on the structure and mechanical properties of 18CrNiMo7-6 steel have been investigated using X-ray diffraction line profile analysis. X-ray diffraction data reveals the phase transformation from austenite to martensitic phase after SP treatments. The results show that multistep shot Peening can more significantly improve the mechanical properties. The optimal Peening intensity of 0.50 + 0.30 + 0.15 mmA is found for 18CrNiMo7-6 steel. With the optimized shot Peening treatment, the maximum compressive residual stress (located at the depth of 20 μm for martensite) and top-surface compressive residual stress of martensite attain the values of 1463 and 1256 MPa, respectively; While those of austenite are 1039 and 766 MPa, respectively. The domain size of 18CrNiMo7-6 steel decreases to 11.1 nm on the top surface after shot Peening with the intensity of 0.50 + 0.30 + 0.15 mmA, and the micro-hardness on the top surface attains the peak value of 1175 HV.
-
uniformity of residual stress distribution on the surface of s30432 austenitic stainless steel by different shot Peening processes
Materials Letters, 2013Co-Authors: K Zhan, Chuanhai Jiang, Vincent JiAbstract:Abstract Compressive residual stress induced by shot Peening can effectively improve the fatigue resistance of the treated component. Much attention has been paid to increase the compressive residual stress value, and the uniformity of residual stress distribution was often ignored, which was also very important for improving the fatigue resistance. In this paper, the uniformity of compressive residual stress distributions on the surface of S30432 austenitic stainless steel after three different shot Peening treatments has been investigated by X-ray diffraction method. The results revealed that compared with traditional shot Peening, multi-step shot Peening (dual shot Peening, triple shot Peening) methods can not only increase the stress value but also make the stress distribution more uniform.
-
effect of prestress state on surface layer characteristic of s30432 austenitic stainless steel in shot Peening process
Materials & Design, 2012Co-Authors: K Zhan, Chuanhai JiangAbstract:Residual stress and microstructure on surface deformed layer of S30432 austenitic stainless steel after shot Peening with different prestress states were investigated. The domain size and micro-strain in the deformed layer were analyzed by Voigt method. The results showed that the compressive residual stress and microstructure were improved significantly after stress shot Peening. The values of compressive residual stress depended on both the prestress state and the measurement directions. Microstructure investigations revealed that smaller domain size and higher micro-strain were induced compared with the conventional shot Peening. And the variations of microstructure were mainly influenced by the values of prestress state. Based on these investigations, it is concluded that stress shot Peening is superior to conventional shot Peening and it is an effective method to improve the surface properties of S30432 austenitic stainless steel.
-
surface layer characteristics of s30432 austenite stainless steel after shot Peening
Materials Transactions, 2012Co-Authors: K Zhan, Chuanhai Jiang, X Y Wu, Vincent JiAbstract:Three types of shot Peening treatments were applied to S30432 stainless steel. The effect of shot Peening intensity and shot Peening method on the residual stress and microstructure has been investigated. The domain size and micro-strain evolutions in near surface layer were characterized systematically via Voigt method. The results reveal that shot Peening could induce compressive residual stress in the deformed layer for all shot Peening conditions. As the shot Peening step and intensity increase, the compressive residual stresses increase in near surface layer, and decease faster in deeper deformed layer. In the deformed layer, the domain size increases, while the micro-strain decreases with the depth increasing. Comparing with the micro-hardness after shot Peening, it is concluded that increasing the shot Peening step is a considerable way to improve the shot Peening effect. [doi:10.2320/matertrans.M2011390]