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Ultrasonic impact peening was applied on welded joints manufactured from Strenx 700 MC high strength low alloy steel with the aim to improve the fatigue properties. Three different surface treatment parameters were tested, which resulted in transformation of the near-surface tensile residual stresses in the weld metal and heat affected zone to comp...
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Context 1
... of the tensile tests of welded joints (in the aswelded state with polished gauge-length surface) are given in Table 4 and when compared to mechanical properties of the base metal (Table 2), the yield point decreased for approximately 50 MPa, while the UTS value was kept approximately the same. The stress-strain curves ( Figure 5) show that the welded material had a significant yield point, which indicates that the welded material kept its ductile properties. The yielding of the test rod 1, in Figure 5, is characterized by two yield points. ...
Context 2
... stress-strain curves ( Figure 5) show that the welded material had a significant yield point, which indicates that the welded material kept its ductile properties. The yielding of the test rod 1, in Figure 5, is characterized by two yield points. This is a result of combined microstructures in the welded joint, where the first yielding started at the microstructure with the lowest mechanical properties, probably the weld metal (later confirmed by the hardness test). ...
Context 3
... correlation with yield points of the original BM and WM cannot be found due to chemical mix and thermal influence of the welding process. For the test rod 2, presented in Figure 5, the described mechanism did not become evident. The elongation of the welded joint is usually higher than of the base metal. ...
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Citations
... Among these different approaches, UIT, based on severe plastic deformation and unrestricted by materials, geometric dimension, form feature, and the application situation of the treated material and component, shows significant advantages in terms of its simple equipment, easy operation, low utilization and maintenance costs, larger residual compressive stress, better process controllability, and a more uniformly treated surface. UIT is considered to be the most Coatings 2023, 13, 2024 3 of 19 economic and effective process, particularly in the case of welded parts and components to eliminate residual stress [25,26], fabricate composite coatings with gradient structure, enhance the bonding strength at the interface between the coating/weld and substrate, improve fatigue resistance, and prolong service life [27,28]. UIT processing is very similar to traditional ultrasonic shot peening but instead of using impact balls, it uses a hemispherical impact needle(s) applied directly to the target materials at a high frequency of more than 20 kHz, so that the substrate is subjected to severe plastic deformation on its surface. ...
This study aims to explore the effects of ultrasonic impact parameters on the surface modification of a stainless steel coating deposited on a medium-carbon low-alloy steel using argon arc surfacing welding. Ultrasonic impact treatment (UIT), at three different vibration strike numbers (40,000 times/(mm2), 57,600 times/(mm2), and 75,000 times/(mm2)) marked UIT–1, UIT–2, and UIT–3, respectively, was carried out to modify the surface structure and properties of the stainless steel coating. The surface morphological and structural features, phase compositions, grain size, topography, micro-mechanical properties, as well as the wear resistance of the coating before and after UIT with different impact parameters were experimentally investigated. The results of optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD) analyses revealed that the grain refinement accompanied by the formation of the strain-induced α′–martensite occurred on the UIT-treated coating surface. With the increase in the vibration strike number, the surface grain size and roughness decreased, while the α′–martensite content increased. Micro-hardness after UIT was increased by about 19% (UIT–1), 39% (UIT–2), and 57% (UIT–3), and the corresponding wear rate obtained was decreased by 39%, 72%, and 85%, respectively. Significant improvements in wear resistance were achieved using UIT. However, an excessive vibration strike number on the per unit area (/mm2) might result in unwanted micro-cracks and delamination on the treated surface, deteriorating the performance of the coating. These findings validate that UIT parameters (such as the vibration strike number on per unit area) are of great importance to bringing about improvements in wear performance, and UIT is found to have a high potential in modifying the surface characteristics and optimizing the mechanical performances of the deposited coating for a wide range of potential applications.
... Correspondingly, it can reduce the amount of welding and painting work, enhance the fatigue life of structures, and, by lowering steel consumption, it significantly reduces energy and resource consumption [1,2]. Due to the high yield strength and low elongation of high-strength steel at room temperature [3], defects such as twist [4], longitudinal curvature [5], flare [6], and end deformation [7] are prone to occur during the roll forming process. Phenomena like cracking at the corners [8,9] and thickness reduction [10] can also occur. ...
This paper describes the use of cold and hot composite forming technology to produce pointed curtain wall profiles. An electromagnetic–temperature coupling model was constructed using ANSYS to study the temperature and electromagnetic field distribution during the forming process. Numerical simulation was used to optimize the process parameters to obtain the optimum heating parameters with a current of 4000 A, a frequency of 35 kHz, and a duration of 2 s. The accuracy of the model was also verified through experiments. The simulation results show that the use of a conductive magnet can improve the induction heating efficiency, increasing the heating frequency and the temperature peak; however, it also increases the temperature difference. Sharp-corner curtain wall profiles were successfully produced using the optimized process parameters. The temperature of the heating zone was measured using an infrared thermal imager, and the relative errors between the maximum heating temperature obtained from the simulation and the actual measured values were 5.37% and 5.02%, respectively, indicating that the finite element model performs well in terms of prediction.
... Note that the techniques that use liquid media include essentially water jet peening (WJP) 8) and its derived methods. Typical SSPD based techniques essentially include shot peening (SP), 913) surface mechanical attrition treatment (SMAT), 1418) ultrasonic shot peening (USP or USSP), 13,1923) ultrasonic nanocrystal surface modification (UNSM), 2427) ultrasonic impact peening or treatment (UIP 28,29) or UIT 3032) ), ultrasonic surface rolling process (USRP), 3338) surface mechanical grinding treatment (SMGT), 3941) surface mechanical rolling treatment (SMRT), 4246) severe shot peening (SSP), 4749) laser shock peening (LSP). 5057) SP is one of the most studied and applied mechanical surface treatment techniques. ...
... 191195) For instance, the fatigue strength at 10 8 cycles of a low alloy steel treated by UIT is enhanced under the stress amplitudes from 370 to 410 MPa. 29) The effects of SSPD on fatigue strength were also investigated under other loading conditions such as rotating bending 60,153,182,196) and torsional loading. 197) Dureau et al. 182) revealed that, the application of SMAT can bring an enhancement of about 30% in fatigue life under rotating bending compared with the initial ground state, and the improvement is more significant than the enhancement observed under tension-compression. ...
This paper gives an overview about some mechanical properties of materials processed by surface severe plastic deformation (SSPD) techniques. SSPD processed materials are classified in terms of their characteristics, and some main generated parameters that determine the output properties of materials are presented. The influences of SSPD on mechanical properties of materials are then reviewed. Furthermore, the roles played by some important parameters such as gradient microstructure, nanostructured layer, compressive residual stress (CRS) and surface integrity are highlighted by discussing their contributions to the mechanical properties of materials. Finally, some conclusions are drawn and possible prospects for future research are underlined.
... The specimens, substrates, were prepared by the grinding procedure. Their surface was mechanically treated by shot peening with parameters Almen intensity 12A, coverage 100 %, chosen according to [24]. Cast steel shots of diameter 0.42 mm were used for the treatment at the incidence angle close to 90° with respect to the specimen surface. ...
... Therefore, a slightly higher temperature, namely 130 °C, was chosen as the experimental temperature. [3,7,18,24,27]. The authors state that application of the shot peening can produce values of the compressive residual stresses up to the size of the yield strength, usually at depths of up 0.1 to 0.2 mm (in the present case the value reached is 0.52 of the yield strength). In the real applications, components, subjected to operating conditions at elevated temperatures, may suffer the thermal relaxation effects, as well. ...
Results of experimental testing of the shot peened steel C55 specimens are presented in this paper. The aim was to establish behaviour of the compressive residual stresses induced by the shot peening at elevated temperatures; namely their stability in terms of temperature and time. Experimental work included verification of the tested material chemical composition, heat treatment (austenitization at 820 °C ± 5 °C for 30 minutes, cooling in the Durixol V70 oil at 20 °C ± 5 °C, high tempering at 450 °C ± 5 °C for 120 minutes, followed by cooling in air), tensile tests according to EN 10002-1 standard, hardness (HRC) measurements, shot peening with parameters Almen intensity 12A and coverage of 100 %, at the incidence angle close to 90° with respect to the specimen surface. The residual stresses state was evaluated by the X-ray diffraction measurement. It was concluded that the elevated temperature of 130 °C and after exposure of 100, 500 and 1000 hours, did not cause a significant decrease in compressive residual stresses.
... A number of publications were also published for the assessment of the effect of cyclic loading on HSLA steels. In this field, the fatigue of MAG-welded joints in HSLA steels was investigated by, e.g., Lahtinen et al. [24] for S700MC steel, Kim et al. [25] for CT100+ steel and Lago et al. [26] for S960MC steel. The assessment of the effect of heat input on the fatigue life of welded joints was investigated by Šebestová et al. [27] for Hybrid Laser-TIG Welding and by Moravec et al. [28] for MAG welds. ...
... A lot of publications deal with the study of the fatigue life of welds in HSLA steels [24][25][26][27]. However, these studies have comprehensively considered the effect of welding on fatigue life and therefore it is not possible to easily quantify the effect of partial aspects of the welding process. ...
Fine-grained steels, which belong to the HSLA (High-Strength Low-Alloy) group of steels, are increasingly used for parts of statically and dynamically loaded constructions. Due to the thermal effect of welding, combined with the inherent stiffness and clamping stiffness of the part, residual stresses are generated in the HAZ (heat-affected zone) which affect the fatigue life of the sub-weld and the entire construction. In this article, a specific temperature cycle measured during welding is used, which, together with a defined clamping stiffness, produces residual stresses of a defined shape and value in the sample. Subsequently, the effect of these stresses on the fatigue life on the change of the S–N curve compared to the annealed material, is assessed. Temperature cycles were applied using a Gleeble 3500 and the residual stresses were analyzed by X-ray diffraction (XRD). It was found that the effect of residual stresses decreased the fatigue strength by 33% compared to the annealed material. It was further found that by using annealing to reduce the residual stresses, it is possible to restore the fatigue life of S700MC steel to the original value of the base material.
... Kinoshita et al. [21] found that shot peening could increase the fatigue strength of SM490YA steel out-of-plane gusset welded joints by two levels. Lago et al. [22] found that ultrasonic impact strengthening could increase the fatigue limit of welded joints of Strenx 700 MC high-strength low-alloy steel from 370 MPa to 410 MPa for n = 10 8 cycles. Sano et al. [23] found that dry laser peening could effectively improve welding defect fatigue performance in laser welding 2024-T3 aluminum alloy specimens by almost doubling the fatigue life when the stress amplitude was 180 MPa and causing a change of than 50 times when the stress amplitude was 120 MPa. ...
The welded joints of 1Cr18Ni9Ti austenitic stainless steel and GH1140 nickel-based superalloy dissimilar materials used in certain types of aero-engine combustion liner components are prone to crack initiation during service, seriously affecting the service life of the combustion liner. In this study, laser shock peening (LSP) was applied to the dissimilar metal weld of 1Cr18Ni9Ti and GH1140, which are used in the combustion liner parts of aero engines. The effects of LSP on the residual stress, microhardness, microstructure and high-cycle fatigue performance of the weld were analyzed. The results show that the residual stress in the weld and heat-affected zones was converted from tensile residual stress to high amplitude compressive residual stress via LSP. Furthermore, the surface hardness of every region of the combustion liner weld was increased, especially in the weld zone, where an increase of 41.4% from 162 HV to 229 HV was observed. Simultaneously, with the introduction of grain refinement, gradient plastic deformation in the depth direction and the dislocation structure of the surface material, the high-cycle fatigue limit of the weld specimen was significantly increased and the fatigue limit of the 1Cr18Ni9Ti/GH1140 welded joint was improved by 65.39%, from 289 to 478 MPa.
... The result is strengthening of the material surface and creation of compressive residual stress field in the sub-surface material's layer. In the field of fatigue, the compressive residual stresses are prolonging fatigue life and result in fatigue limit increase usually up to 20 % Baiker et al., 2012;Miková et al., 2013;Trško et al., 2014;Lago et al., 2019;Ulewicz and Mazur, 2013;Vasko et al., 2017). However, it should be noted that incorrectly selected shot peening or severe shot peening parameters vs. material parameters can cause a reduction on fatigue strength (Holzman and Klesnil, 1972;Nový et al., 2008). ...
... The finishing operation on the specimens was grinding. Specimens were divided into two groups and one of them was subsequently treated by SP with parameters chosen according to works Bokůvka et al., 2014;Baiker et al., 2012;Miková et al., 2013;Trško et al., 2014;Lago et al. 2019. The SP parameters were as follows: Almen intensity 12A, coverage 100%. ...
... The compressive residual stresses levels are in the axial direction (φ = 0°) and in the tangencial direction (φ = 90°) practically the same. The above facts are in agreement with the works Moravčík et al., 2021;Bokůvka et al., 2014;Baiker et al., 2012;Miková et al., 2013;Trško et al., 2014;Lago et al., 2019. The authors of these works state that the application of SP can achieve values of compressive residual stresses up to the size of the yield point. ...
Influence of shot peening on the wear behaviour of medium carbon, C55 steel was experimentally verified. Experimental work included determination of the chemical composition, heat treatment, microstructure evaluation, mechanical properties measurement, shot peening treatment, the magnitude of the compressive residual stresses was evaluated, roughness profiles measurement and finally the friction tests. The results evidence the significant role played by the applied shot peening on wear behaviour of medium carbon steel. An important effect of surface roughness has been demonstrated. The coefficient of friction after shot peening compared to ground surface increased, 1.44 – 1.85 times.
... Due to its operability with directional impacts on the surface of materials, UIT/UNSM is considered as a promising technique for strengthening parts with welded joints. The improvement in the fatigue strength of welded joints after UNSM has been generally observed and investigated in a large number of studies [68][69][70][71][72][73]. For instance, for a low-alloy steel, Strenx 700 MC, it was discovered by Lago et al. [72] that UIT was able to transform the tensile residual stresses in the welded material and heat-affected zone to compressive residual stresses. ...
... The improvement in the fatigue strength of welded joints after UNSM has been generally observed and investigated in a large number of studies [68][69][70][71][72][73]. For instance, for a low-alloy steel, Strenx 700 MC, it was discovered by Lago et al. [72] that UIT was able to transform the tensile residual stresses in the welded material and heat-affected zone to compressive residual stresses. The fatigue limit at 10 8 cycles was enhanced from 370 MPa to 410 MPa. ...
As a promising surface treatment technique, the surface mechanical attrition treatment (SMAT) has been applied to enhance mechanical properties of various materials. Through multidi-rectional severe plastic deformation, SMAT is able to nanocrystallize the near surface region of materials. The nanostructured layer associated with high compressive residual stresses coupled with a work hardening layer can provide the treated materials with an improved fatigue resistance. The present work gives a comprehensive review on the fatigue strength of SMATed materials. First of all, a brief introduction is given on the basic elements of SMAT and surface modifications induced by this treatment. The fatigue strength of a large variety of SMATed materials with different loading conditions is reviewed, including low-cycle fatigue (LCF), high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF). Then, the mechanism of enhancement or reduction is explained through a detailed review on the effects of several factors, such as residual stress, surface quality and nano-crystalline grains. In addition, the combined effect of SMAT coupled with other processes is also reviewed. Trends and prospects of the current research are summarized at the end.
... These methods can prevent crack initiation and propagation, thereby preventing the onset of the failure. Researchers used various SPD techniques, such as shot peening (SP) [9][10][11], severe shot peening (SSP) [12][13][14], ultrasonic impact peening (UIP) [15,16], ...
Ultrasonic nanocrystal surface modification (UNSM) is a unique, mechanical, impact-based surface severe plastic deformation (S2PD) method. This newly developed technique finds diverse applications in the aerospace, automotive, nuclear, biomedical, and chemical industries. The severe plastic deformation (SPD) during UNSM can generate gradient nanostructured surface (GNS) layers with remarkable mechanical properties. This review paper elucidates the current state-of-the-art UNSM technique on a broad range of engineering materials. This review also summarizes the effect of UNSM on different mechanical properties, such as fatigue, wear, and corrosion resistance. Furthermore, the effect of USNM on microstructure development and grain refinement is discussed. Finally, this study explores the applications of the UNSM process.
... Fatigue strength of arc-welded joints is commonly said to be lower than that of the base metal, because of stress concentration, tensile residual stress, and deterioration of the mechanical properties due to microstructural change at the weld toe. Various post-weld treatments have been proposed to increase fatigue strength of the welds, and are generally divided into two groups of residual stress modification, those of peening [1][2][3][4] and post-weld heat treatment [5,6], and weld geometry modification such as grinding [7][8][9] and remelting [10][11][12]. Residual stress modification is more effective than weld geometry modification under low applied stress amplitude, but seems not effective under high applied stress amplitude, because of residual stress relaxation during fatigue [13]. ...
Friction stir processing (FSP) enables surface modifications can likely be applied as a new post-weld treatment for improving fatigue strength. When applying FSP to high-strength materials, tool wear occurring at the interface between the tool tip and the topmost steel layer has been regarded as an unavoidable issue and is related to the tool rotational speed. The present study investigated the relationship between the tool rotational speed and fatigue strength of arc-welded high-strength low-alloy (HSLA) steel joints with weld toes subjected to FSP using a spherical-tip WC tool. FSP was conducted on the weld toe of HSLA steel joints with various tool rotational speeds. Tool wear increased with increase in tool rotational speed, and consequently contents of constituent elements of the WC tool increased in the topmost steel layer of weld toes, leading to large increase in fatigue strength. One reason for the increase with tool rotational speed is significant increase in solid solution hardening due to supersaturated W and C in the topmost steel layer consisting of martensite laths. The hardened topmost steel layer prevented fatigue crack initiation, and the increased fatigue strength depended on the contents of supersaturated W and C. Alloying of the topmost steel layer with tool constituent elements of W and C accompanied with WC tool wear during FSP is unique additive manufacturing to increase the fatigue strength of welded joints, and can be employed locally on structural components susceptible to fatigue.
