Pub Date : 2024-11-17DOI: 10.1016/j.wear.2024.205653
Junming Lu , Chunyu Ma , Lei Zhang , Zhihao He , Baisong Guo , Jiang Wei , Dahai Zeng , Wei Li , Yangzhen Liu
A gradient design of material is an effective way to solve the inhomogeneity of current-carrying damage. However, service conditions have a great influence on the current-carrying damage of gradient composites. To promote the development and application of current-carrying friction materials, it is necessary to elucidate the current-carrying damage mechanism of gradient composites with different service conditions. To this end, the gradient copper-graphite composites were prepared by hot pressing and sintering, and the variation in the current-carrying properties of the composites with loads were investigated in this study. The results showed that with increasing load, the wear rate of the composites initially decreased and then increased, while the current-carrying properties initially improved and then deteriorated. The composite exhibited better current-carrying tribological performance at the load of 55 N, and the wear rate of the composite was 1.59 × 10−4 mm3 N−1 m−1. Meanwhile, the current carrying efficiency and current carrying stability was 98.5 % and 2.2 %, respectively. The main wear mechanism of the composite at 55 N was plastic deformation.
材料的梯度设计是解决载流损伤不均匀性的有效方法。然而，使用条件对梯度复合材料的载流损伤有很大影响。为了促进载流摩擦材料的开发和应用，有必要阐明不同服役条件下梯度复合材料的载流损伤机理。为此，本研究通过热压和烧结制备了梯度铜石墨复合材料，并研究了复合材料载流性能随载荷的变化。结果表明，随着载荷的增加，复合材料的磨损率先降低后升高，而载流性能则先改善后恶化。在载荷为 55 N 时，复合材料表现出更好的载流摩擦学性能，复合材料的磨损率为 1.59 × 10-4 mm3 N-1 m-1。同时，载流效率和载流稳定性分别为 98.5 % 和 2.2 %。复合材料在 55 N 载荷下的主要磨损机制是塑性变形。
{"title":"Effect of normal load on damage mechanism of gradient copper-graphite composites under electric current","authors":"Junming Lu , Chunyu Ma , Lei Zhang , Zhihao He , Baisong Guo , Jiang Wei , Dahai Zeng , Wei Li , Yangzhen Liu","doi":"10.1016/j.wear.2024.205653","DOIUrl":"10.1016/j.wear.2024.205653","url":null,"abstract":"<div><div>A gradient design of material is an effective way to solve the inhomogeneity of current-carrying damage. However, service conditions have a great influence on the current-carrying damage of gradient composites. To promote the development and application of current-carrying friction materials, it is necessary to elucidate the current-carrying damage mechanism of gradient composites with different service conditions. To this end, the gradient copper-graphite composites were prepared by hot pressing and sintering, and the variation in the current-carrying properties of the composites with loads were investigated in this study. The results showed that with increasing load, the wear rate of the composites initially decreased and then increased, while the current-carrying properties initially improved and then deteriorated. The composite exhibited better current-carrying tribological performance at the load of 55 N, and the wear rate of the composite was 1.59 × 10<sup>−4</sup> mm<sup>3</sup> N<sup>−1</sup> m<sup>−1</sup>. Meanwhile, the current carrying efficiency and current carrying stability was 98.5 % and 2.2 %, respectively. The main wear mechanism of the composite at 55 N was plastic deformation.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205653"},"PeriodicalIF":5.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.wear.2024.205642
Hao Jiang, David A. McClintock, Drew E. Winder
Cavitation-induced erosion damage in different Spallation Neutron Source (SNS) target designs are simulated using explicit finite element–based techniques and compared with observations of erosion in targets after operation. The efficacy of the previously developed method, called saturation time, was evaluated using erosion-damaged samples from new target designs. A new metric called maximum bubble size was implemented under the rationale that larger cavitation bubbles will collapse more intensely. The maximum cavitation bubble size over 1 ms of simulated time was calculated based on the Rayleigh–Plesset equation for each element integration point and presented as a contour map at the vessel surface for assessing with erosion observations. SNS targets are now operated with helium gas injection to reduce cavitation damage. A simulation method using a material model for the mixture of mercury and gas bubbles was recently developed and used to account for the effect of small gas bubbles on the structural response of the target vessel. This work compares the new method's results with observed cavitation damage. Maps of the calculated maximum bubble size for targets operated with and without gas injection were compared with photographs of erosion damage observed in SNS targets. The patterns in maximum bubble size maps correlated well with observations of erosion patterns in target vessels after service. Advantages and challenges of the maximum bubble size simulation technique are provided, and differences between results from the previous and the newly proposed metric are discussed.
{"title":"Assessment of simulated and observed cavitation-induced erosion damage in spallation neutron source target vessels","authors":"Hao Jiang, David A. McClintock, Drew E. Winder","doi":"10.1016/j.wear.2024.205642","DOIUrl":"10.1016/j.wear.2024.205642","url":null,"abstract":"<div><div>Cavitation-induced erosion damage in different Spallation Neutron Source (SNS) target designs are simulated using explicit finite element–based techniques and compared with observations of erosion in targets after operation. The efficacy of the previously developed method, called saturation time, was evaluated using erosion-damaged samples from new target designs. A new metric called maximum bubble size was implemented under the rationale that larger cavitation bubbles will collapse more intensely. The maximum cavitation bubble size over 1 ms of simulated time was calculated based on the Rayleigh–Plesset equation for each element integration point and presented as a contour map at the vessel surface for assessing with erosion observations. SNS targets are now operated with helium gas injection to reduce cavitation damage. A simulation method using a material model for the mixture of mercury and gas bubbles was recently developed and used to account for the effect of small gas bubbles on the structural response of the target vessel. This work compares the new method's results with observed cavitation damage. Maps of the calculated maximum bubble size for targets operated with and without gas injection were compared with photographs of erosion damage observed in SNS targets. The patterns in maximum bubble size maps correlated well with observations of erosion patterns in target vessels after service. Advantages and challenges of the maximum bubble size simulation technique are provided, and differences between results from the previous and the newly proposed metric are discussed.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205642"},"PeriodicalIF":5.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.wear.2024.205630
Lai Hu , Zixi Wang , Jian Wang , Yuming Wang
UTWB (Ultra-thin-walled bearings) are mainly used in high-precision robots and as power transmission components. In this study, the raceway wear mechanism of UTWB after high service (continuous 7000 h wear test) was analyzed. From the macroscopic observation, it is observed that the surface layer of the raceway has roll-slip wear. The wear mechanism was derivative analyzed and evaluated from the experimental conclusions. Another form of surface damage, associated with oscillatory movements tangential to the surface, was fretting wear. Compared with the residual stress of the non-high service raceway, the tangential and axial residual stresses of the outer and inner raceways with high service wear increased. Grain delamination appeared on the subsurface layer of the high serviced outer and inner ring raceway. The rolling wear and sliding wear of the inner ring raceway were more serious than those of the outer ring raceway. The formation of nanocrystalline layer increases the surface hardness of the raceway. Meanwhile, with the transfer from the surface layer of the raceway to the subsurface layer, the degree of grain refinement gradually decreases and the interplanar crystal spacing gradually increases. Through the above data analysis, the roll-slip wear mechanism of UTWB raceway was evaluated in multiple dimensions, and the reliability scheme to improve the actual working conditions of UTWB raceway processing-wear-service was put forward, which provides scheme and data support for relevant manufacturing enterprises and scholars.
{"title":"Derivative analysis and evaluation of roll-slip fretting wear mechanism of ultra-thin-walled bearings under high service","authors":"Lai Hu , Zixi Wang , Jian Wang , Yuming Wang","doi":"10.1016/j.wear.2024.205630","DOIUrl":"10.1016/j.wear.2024.205630","url":null,"abstract":"<div><div>UTWB (Ultra-thin-walled bearings) are mainly used in high-precision robots and as power transmission components. In this study, the raceway wear mechanism of UTWB after high service (continuous 7000 h wear test) was analyzed. From the macroscopic observation, it is observed that the surface layer of the raceway has roll-slip wear. The wear mechanism was derivative analyzed and evaluated from the experimental conclusions. Another form of surface damage, associated with oscillatory movements tangential to the surface, was fretting wear. Compared with the residual stress of the non-high service raceway, the tangential and axial residual stresses of the outer and inner raceways with high service wear increased. Grain delamination appeared on the subsurface layer of the high serviced outer and inner ring raceway. The rolling wear and sliding wear of the inner ring raceway were more serious than those of the outer ring raceway. The formation of nanocrystalline layer increases the surface hardness of the raceway. Meanwhile, with the transfer from the surface layer of the raceway to the subsurface layer, the degree of grain refinement gradually decreases and the interplanar crystal spacing gradually increases. Through the above data analysis, the roll-slip wear mechanism of UTWB raceway was evaluated in multiple dimensions, and the reliability scheme to improve the actual working conditions of UTWB raceway processing-wear-service was put forward, which provides scheme and data support for relevant manufacturing enterprises and scholars.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205630"},"PeriodicalIF":5.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.wear.2024.205634
Xiaotian Wu , Lihong Su , Anh Kiet Tieu , Jun Cheng , Cuong Nguyen , Hongtao Zhu , Jun Yang , Guanyu Deng
In this study, a new V-containing high-entropy alloy (HEA) with the chemical composition of Al0.5CrFeNiV0.5 has been developed. Its microstructural features and phase constitutions were investigated by several techniques, including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The as-cast Al0.5CrFeNiV0.5 HEA exhibits an average Vickers hardness of around 570.5 HV, a compressive strength of about 2.53 GPa and a plasticity of around 22.1 %. In addition, the HEA still exhibits very high compressive strength of about 1218.6 MPa at 600 °C, but it decreases quickly to around 586 MPa at 700 °C and 301 MPa at 800 °C. On the other hand, high-temperature sliding wear tests of as-cast HEA against the Si3N4 ceramic balls revealed a slight change of friction coefficient in a range of 0.4–0.5 between RT and 800 °C. However, the wear rate of HEA was found to increase monotonically with increasing the temperature, and was particularly higher when temperature exceeded 600 °C. The associated mechanisms have been discussed in details based on chemical composition analysis, worn surface morphology observations as well as the characterizations of the wear track cross-sections.
本研究开发了一种新的含钒高熵合金（HEA），其化学成分为 Al0.5CrFeNiV0.5。通过 X 射线衍射、扫描电子显微镜和透射电子显微镜等多种技术对其微观结构特征和相组成进行了研究。铸造后的 Al0.5CrFeNiV0.5 HEA 平均维氏硬度约为 570.5 HV，抗压强度约为 2.53 GPa，塑性约为 22.1%。此外，HEA 在 600 °C 时仍表现出极高的抗压强度（约 1218.6 MPa），但在 700 °C 时迅速降至约 586 MPa，在 800 °C 时降至 301 MPa。另一方面，对铸态 HEA 与 Si3N4 陶瓷球的高温滑动磨损测试表明，在 RT 和 800 °C 之间，摩擦系数在 0.4-0.5 范围内略有变化。然而，HEA 的磨损率随着温度的升高而单调增加，尤其是当温度超过 600 °C 时磨损率更高。根据化学成分分析、磨损表面形态观察以及磨损轨迹截面特征，详细讨论了相关机理。
{"title":"Microstructure, mechanical properties and high-temperature sliding wear response of a new Al0.5CrFeNiV0.5 high-entropy alloy","authors":"Xiaotian Wu , Lihong Su , Anh Kiet Tieu , Jun Cheng , Cuong Nguyen , Hongtao Zhu , Jun Yang , Guanyu Deng","doi":"10.1016/j.wear.2024.205634","DOIUrl":"10.1016/j.wear.2024.205634","url":null,"abstract":"<div><div>In this study, a new V-containing high-entropy alloy (HEA) with the chemical composition of Al<sub>0.5</sub>CrFeNiV<sub>0.5</sub> has been developed. Its microstructural features and phase constitutions were investigated by several techniques, including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The as-cast Al<sub>0.5</sub>CrFeNiV<sub>0.5</sub> HEA exhibits an average Vickers hardness of around 570.5 HV, a compressive strength of about 2.53 GPa and a plasticity of around 22.1 %. In addition, the HEA still exhibits very high compressive strength of about 1218.6 MPa at 600 °C, but it decreases quickly to around 586 MPa at 700 °C and 301 MPa at 800 °C. On the other hand, high-temperature sliding wear tests of as-cast HEA against the Si<sub>3</sub>N<sub>4</sub> ceramic balls revealed a slight change of friction coefficient in a range of 0.4–0.5 between RT and 800 °C. However, the wear rate of HEA was found to increase monotonically with increasing the temperature, and was particularly higher when temperature exceeded 600 °C. The associated mechanisms have been discussed in details based on chemical composition analysis, worn surface morphology observations as well as the characterizations of the wear track cross-sections.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205634"},"PeriodicalIF":5.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.wear.2024.205643
Yongshi Zhang , Zhenguang Liu , Yiming Wang , Zigang Chen , Hongyan Liu , Xiaonan Wang
Welded joints of wear-resistant steel often experience wear problems due to a lack of strengthening particles. This study investigates the wear behavior of welded joints produced by laser-arc hybrid welding (LAHW) on wear-resistant steel with low strength (WRL) and high strength (WRH). The microstructure, wear rate, wear track morphology, and profile were analyzed. The experimental results indicate that the microstructures of the fusion zone (FZ), coarse-grain heat-affected zone (CGHAZ), fine-grain heat-affected zone (FGHAZ), and intercritical heat-affected zone (ICHAZ) in both similar and dissimilar welded joints consist of martensite, coarsening martensite, martensite + ferrite, and martensite + ferrite + bainite, respectively, regardless of WRL and WRH. The wear resistance of the FZ was weaker than those of both WRL and WRH. The wear direction, namely parallel or perpendicular to the welded seams, affects the wear behavior. The cross-sectional areas of the wear tracks in both similar and dissimilar welded joints showed minimal changes in the HAZ and FZ. The wear mechanisms in the different HAZs varied due to microstructural differences.
{"title":"Study on microstructure and sliding wear behavior of similar and dissimilar welded joints produced by laser-arc hybrid welding of wear-resistant steels","authors":"Yongshi Zhang , Zhenguang Liu , Yiming Wang , Zigang Chen , Hongyan Liu , Xiaonan Wang","doi":"10.1016/j.wear.2024.205643","DOIUrl":"10.1016/j.wear.2024.205643","url":null,"abstract":"<div><div>Welded joints of wear-resistant steel often experience wear problems due to a lack of strengthening particles. This study investigates the wear behavior of welded joints produced by laser-arc hybrid welding (LAHW) on wear-resistant steel with low strength (WRL) and high strength (WRH). The microstructure, wear rate, wear track morphology, and profile were analyzed. The experimental results indicate that the microstructures of the fusion zone (FZ), coarse-grain heat-affected zone (CGHAZ), fine-grain heat-affected zone (FGHAZ), and intercritical heat-affected zone (ICHAZ) in both similar and dissimilar welded joints consist of martensite, coarsening martensite, martensite + ferrite, and martensite + ferrite + bainite, respectively, regardless of WRL and WRH. The wear resistance of the FZ was weaker than those of both WRL and WRH. The wear direction, namely parallel or perpendicular to the welded seams, affects the wear behavior. The cross-sectional areas of the wear tracks in both similar and dissimilar welded joints showed minimal changes in the HAZ and FZ. The wear mechanisms in the different HAZs varied due to microstructural differences.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205643"},"PeriodicalIF":5.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.wear.2024.205629
Wei Liu , Ningbo Zhe , Fubing Bao , Ming Kong , Zhi Feng , Jinqing Wang , Xiaoyu Liang
Deformation and erosion of steel due to particle impacts in high-temperature environments are common issues in industrial applications. Under high-temperature conditions, an oxide layer forms that affects the deformation and erosion of the steel surface following particle impacts. Studying the interaction mechanism of oxidation and deformation (erosion) is of considerable significance. Traditional research methods primarily involve ex-situ measurements on samples post-erosion and oxidation, which cannot capture the morphological changes of the steel surface immediately following particle impact. Utilizing 3D digital holography (DH) technology, this paper develops a measurement system to investigate the surface morphological changes in steel induced by single particle impacts. We utilized this experimental system to measure the impact crater morphology of 500 μm zirconia particles impacting Q690 steel sheets. Our findings indicate that Hertzian ring cracks formation is significantly affected by heating temperature and impact angle. Notably, oxide layer peeling and erosion occurred at an impact angle of 30°. Additionally, impact crater depths at a 90° angle and impact speeds ranging from 1 to 20 m/s varied between 0.66 and 4.25 μm, with crater depths showing a correlation to the thickness of the oxide layer. Concurrently, in-situ measurements of the impact crater healing process during heating revealed that the crater formed at a 30° impact angle, which had numerous microcracks, exhibited significantly better healing compared to the crater formed at a 90° impact angle. The thickening process of the oxide layer were also analyzed, leading to the derivation of the oxide layer growth kinetic equation based on the measurement data: . This study is the first to use DH technology to measure the surface morphology of steel and to conduct in-situ analysis of the oxide layer thickening process following particle impact and during heating. This approach provides a novel perspective for understanding the erosion-oxidation interaction mechanism.
{"title":"3D digital holography for measuring particle impact crater morphology and in-situ analysis of oxidation healing on steel surfaces","authors":"Wei Liu , Ningbo Zhe , Fubing Bao , Ming Kong , Zhi Feng , Jinqing Wang , Xiaoyu Liang","doi":"10.1016/j.wear.2024.205629","DOIUrl":"10.1016/j.wear.2024.205629","url":null,"abstract":"<div><div>Deformation and erosion of steel due to particle impacts in high-temperature environments are common issues in industrial applications. Under high-temperature conditions, an oxide layer forms that affects the deformation and erosion of the steel surface following particle impacts. Studying the interaction mechanism of oxidation and deformation (erosion) is of considerable significance. Traditional research methods primarily involve ex-situ measurements on samples post-erosion and oxidation, which cannot capture the morphological changes of the steel surface immediately following particle impact. Utilizing 3D digital holography (DH) technology, this paper develops a measurement system to investigate the surface morphological changes in steel induced by single particle impacts. We utilized this experimental system to measure the impact crater morphology of 500 μm zirconia particles impacting Q690 steel sheets. Our findings indicate that Hertzian ring cracks formation is significantly affected by heating temperature and impact angle. Notably, oxide layer peeling and erosion occurred at an impact angle of 30°. Additionally, impact crater depths at a 90° angle and impact speeds ranging from 1 to 20 m/s varied between 0.66 and 4.25 μm, with crater depths showing a correlation to the thickness of the oxide layer. Concurrently, in-situ measurements of the impact crater healing process during heating revealed that the crater formed at a 30° impact angle, which had numerous microcracks, exhibited significantly better healing compared to the crater formed at a 90° impact angle. The thickening process of the oxide layer were also analyzed, leading to the derivation of the oxide layer growth kinetic equation based on the measurement data: <span><math><mrow><msubsup><mi>K</mi><mi>p</mi><mn>0</mn></msubsup><mo>=</mo><mn>2.39</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>8</mn></mrow></msup><mspace></mspace><mi>exp</mi><mrow><mo>(</mo><mrow><mo>−</mo><mn>17401</mn><mo>/</mo><mi>R</mi><mi>T</mi></mrow><mo>)</mo></mrow></mrow></math></span>. This study is the first to use DH technology to measure the surface morphology of steel and to conduct in-situ analysis of the oxide layer thickening process following particle impact and during heating. This approach provides a novel perspective for understanding the erosion-oxidation interaction mechanism.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205629"},"PeriodicalIF":5.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.wear.2024.205640
Dongfang Zeng , Xu Zhang , Song Lu , Yanhua Gong , Jun Li , Xi Chen , Yihui Dong , Liantao Lu
Polygonization of railway wheels poses a significant challenge for the wheel-rail system. Despite the evidence from engineering practices highlighting the substantial impact of material factors on the polygonization resistance of railway wheels, research in this field remains limited. This study investigates two types of railway wheels, namely non-alloyed and alloyed wheels, which demonstrate different polygonization resistance under identical operating conditions. It involves microstructural analysis and hardness testing for the matrix materials and plastic deformation layer (PDL) of full-scale wheel, twin-disc testing for wheel steels, followed by analyzing the PDL of test wheel discs. The findings demonstrate that the full-scale wheel and test wheel disc exhibit consistency in terms of polygonization resistance, PDL microstructure, and microhardness, suggesting that the twin-disc test can be employed for material comparison regarding polygonization resistance. In addition, the alloyed wheel was found to exhibit better polygonization resistance at the external region of the wheel rim due to its higher resistance to plastic deformation and wear, while it demonstrates poorer polygonization resistance at the internal region of the wheel rim due to its lower wear resistance. Furthermore, the wave troughs display significant plastic deformation, dynamic recrystallization, and strain hardening near the contact surface, indicating a higher slip ratio at these locations. In contrast, the wave crests predominantly exhibit these characteristics in the subsurface region, indicating that the wave crests experience impact loading.
{"title":"Evaluation of polygonization resistance of two wheel steels from full-scale railway wheels and small test discs","authors":"Dongfang Zeng , Xu Zhang , Song Lu , Yanhua Gong , Jun Li , Xi Chen , Yihui Dong , Liantao Lu","doi":"10.1016/j.wear.2024.205640","DOIUrl":"10.1016/j.wear.2024.205640","url":null,"abstract":"<div><div>Polygonization of railway wheels poses a significant challenge for the wheel-rail system. Despite the evidence from engineering practices highlighting the substantial impact of material factors on the polygonization resistance of railway wheels, research in this field remains limited. This study investigates two types of railway wheels, namely non-alloyed and alloyed wheels, which demonstrate different polygonization resistance under identical operating conditions. It involves microstructural analysis and hardness testing for the matrix materials and plastic deformation layer (PDL) of full-scale wheel, twin-disc testing for wheel steels, followed by analyzing the PDL of test wheel discs. The findings demonstrate that the full-scale wheel and test wheel disc exhibit consistency in terms of polygonization resistance, PDL microstructure, and microhardness, suggesting that the twin-disc test can be employed for material comparison regarding polygonization resistance. In addition, the alloyed wheel was found to exhibit better polygonization resistance at the external region of the wheel rim due to its higher resistance to plastic deformation and wear, while it demonstrates poorer polygonization resistance at the internal region of the wheel rim due to its lower wear resistance. Furthermore, the wave troughs display significant plastic deformation, dynamic recrystallization, and strain hardening near the contact surface, indicating a higher slip ratio at these locations. In contrast, the wave crests predominantly exhibit these characteristics in the subsurface region, indicating that the wave crests experience impact loading.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205640"},"PeriodicalIF":5.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.wear.2024.205632
Charlie Salame, Amir Malakizadi, Uta Klement
Sustainable machining in micro-alloyed carbon steels necessitates a thorough understanding of microstructural variations and their subsequent influence on the machinability of different batches. This research investigates the machinability variation between two batches of a modified pearlitic-ferritic C38 micro-alloyed steel with a similar nominal chemical composition, through correlation of their tool wear responses at different cutting conditions to discrepancies in the microstructure and non-metallic inclusions between both batches. One batch of steel exhibits enhanced machinability for all investigated cutting conditions, showing remarkably different levels of wear development under similar cutting conditions and spiral cutting lengths. The different wear responses are then compared in association with the thermo-mechanical loads and microstructural discrepancies, where the less machinable batch is determined to have a lower ferritic volume fraction, higher hardness, and more abrasive nitrides than the other batch.
{"title":"On the influence of batch-to-batch microstructural variations on tool wear when machining C38 micro-alloyed steel","authors":"Charlie Salame, Amir Malakizadi, Uta Klement","doi":"10.1016/j.wear.2024.205632","DOIUrl":"10.1016/j.wear.2024.205632","url":null,"abstract":"<div><div>Sustainable machining in micro-alloyed carbon steels necessitates a thorough understanding of microstructural variations and their subsequent influence on the machinability of different batches. This research investigates the machinability variation between two batches of a modified pearlitic-ferritic C38 micro-alloyed steel with a similar nominal chemical composition, through correlation of their tool wear responses at different cutting conditions to discrepancies in the microstructure and non-metallic inclusions between both batches. One batch of steel exhibits enhanced machinability for all investigated cutting conditions, showing remarkably different levels of wear development under similar cutting conditions and spiral cutting lengths. The different wear responses are then compared in association with the thermo-mechanical loads and microstructural discrepancies, where the less machinable batch is determined to have a lower ferritic volume fraction, higher hardness, and more abrasive nitrides than the other batch.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205632"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.wear.2024.205635
Xiaohong Hao , Haolong Wang , Xiaowen Sun , Yuefeng Wang , Fucheng Zhang , Jing Zhao , Tiansheng Wang
In this study, the wear resistance of two high-Mn austenitic steels, i.e., Fe−18.5Mn−7Cr−0.6C and Fe−18.5Mn−7Cr−0.6C−0.21N was tested in dry sliding friction on a disc friction and wear testing machine (MMU-5G). The wear behavior and microstructure evolution of the two tested steels were investigated. The results revealed that adding N enhanced the wear resistance of high-Mn austenitic steel due to the synergistic effects of hardness, wear hardening, and oxide layer. Interstitial N atoms increased the matrix hardness and decreased the stacking fault energy (SFE). The lower SFE facilitated wear hardening, and the active mechanical twins along with the higher dislocation density induced the formation of a thicker nanocrystalline layer with finer grains. The nanocrystalline layer with higher surface activity promoted the adsorption of a protective oxide layer. These factors decreased the surface roughness, coefficient of friction (COF), and wear rate of N-alloyed high-Mn austenitic steel. This study provided valuable insights into the application of N-alloyed high-Mn austenitic steels under dry sliding friction conditions.
本研究在圆盘摩擦磨损试验机（MMU-5G）上测试了两种高锰奥氏体钢（即 Fe-18.5Mn-7Cr-0.6C 和 Fe-18.5Mn-7Cr-0.6C-0.21N）在干滑动摩擦中的耐磨性。研究了两种测试钢的磨损行为和微观结构演变。结果表明，由于硬度、磨损硬化和氧化层的协同作用，添加 N 增强了高锰奥氏体钢的耐磨性。间隙 N 原子提高了基体硬度，降低了堆积断层能（SFE）。较低的堆叠断层能促进了磨损硬化，而活跃的机械孪晶和较高的位错密度促使形成了具有较细晶粒的较厚纳米晶层。表面活性较高的纳米晶层促进了保护性氧化层的吸附。这些因素降低了 N 合金高锰奥氏体钢的表面粗糙度、摩擦系数（COF）和磨损率。这项研究为 N 合金高锰奥氏体钢在干滑动摩擦条件下的应用提供了宝贵的见解。
{"title":"Enhancing dry sliding wear resistance of high-Mn austenitic steel by adding N","authors":"Xiaohong Hao , Haolong Wang , Xiaowen Sun , Yuefeng Wang , Fucheng Zhang , Jing Zhao , Tiansheng Wang","doi":"10.1016/j.wear.2024.205635","DOIUrl":"10.1016/j.wear.2024.205635","url":null,"abstract":"<div><div>In this study, the wear resistance of two high-Mn austenitic steels, i.e., Fe−18.5Mn−7Cr−0.6C and Fe−18.5Mn−7Cr−0.6C−0.21N was tested in dry sliding friction on a disc friction and wear testing machine (MMU-5G). The wear behavior and microstructure evolution of the two tested steels were investigated. The results revealed that adding N enhanced the wear resistance of high-Mn austenitic steel due to the synergistic effects of hardness, wear hardening, and oxide layer. Interstitial N atoms increased the matrix hardness and decreased the stacking fault energy (SFE). The lower SFE facilitated wear hardening, and the active mechanical twins along with the higher dislocation density induced the formation of a thicker nanocrystalline layer with finer grains. The nanocrystalline layer with higher surface activity promoted the adsorption of a protective oxide layer. These factors decreased the surface roughness, coefficient of friction (COF), and wear rate of N-alloyed high-Mn austenitic steel. This study provided valuable insights into the application of N-alloyed high-Mn austenitic steels under dry sliding friction conditions.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205635"},"PeriodicalIF":5.3,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.wear.2024.205628
Farzin Darihaki, Siamack A. Shirazi
Reducers or contraction pipes are commonly used in various piping systems that involve the transport of fluids containing solid particles. Erosion experiments are performed for a reducer with air and 75 μm and 300 μm particles. Erosion visualization tests show two high erosion zones on the reducer and downstream pipe. Measurements of thickness loss provide erosion rates of a similar magnitude for these hot zones, while maximum erosion for 300 μm particles is 1.87 times the 75 μm particles. Uncertainty estimations suggest factors of 0.6–2 for the lower and upper bounds of erosion, respectively. Computational Fluid Dynamics (CFD) simulations using erosion models provide the pattern and trend of the erosion as observed in the experiments, but they provide similar maximum erosion rates for both particle sizes. The computational model indicates that the dynamic deformation of the geometry due to material removal by particle impacts has insignificant effects on the maximum erosion for test conditions under 250 h.
{"title":"Experimental and computational investigation of solid particle erosion for gas-solid flows in a reducer geometry","authors":"Farzin Darihaki, Siamack A. Shirazi","doi":"10.1016/j.wear.2024.205628","DOIUrl":"10.1016/j.wear.2024.205628","url":null,"abstract":"<div><div>Reducers or contraction pipes are commonly used in various piping systems that involve the transport of fluids containing solid particles. Erosion experiments are performed for a reducer with air and 75 μm and 300 μm particles. Erosion visualization tests show two high erosion zones on the reducer and downstream pipe. Measurements of thickness loss provide erosion rates of a similar magnitude for these hot zones, while maximum erosion for 300 μm particles is 1.87 times the 75 μm particles. Uncertainty estimations suggest factors of 0.6–2 for the lower and upper bounds of erosion, respectively. Computational Fluid Dynamics (CFD) simulations using erosion models provide the pattern and trend of the erosion as observed in the experiments, but they provide similar maximum erosion rates for both particle sizes. The computational model indicates that the dynamic deformation of the geometry due to material removal by particle impacts has insignificant effects on the maximum erosion for test conditions under 250 h.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"562 ","pages":"Article 205628"},"PeriodicalIF":5.3,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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