Biwen Yang, Bo Song, Liang Chen, Honghong Sun, Derek O. Northwood, Kristian E. Waters, Hao Ma
The desulfurization capacity of top slag in the process of pre-desulfurization of hot metal containing vanadium and titanium was researched. The top slag system of CaO-SiO2-MgO-Al2O3-TiO2-VOx that was formed by blast furnace slag and a CaO desulfurization agent reduced the sulfur in hot metal from 0.08 wt.% to 0.02 wt.%. It was found that the resulfurization of the slag happened in the later periods of the desulfurization process. The vanadium–titanium oxides were both acidic in the desulfurization slag. TiO2 and VOx reacted with the basic oxides to form CaTiO3 and MgV2O4 at 1623 K, which reduced free CaO and was not conducive to top slag desulfurization. The results of calculation showed that the top slag desulfurization accounted for 15% of the total desulfurization. Using the ionic and molecule coexistence theory of slag structure, it is shown that the desulfurization efficiency could be enhanced by adjusting both the amount of desulfurization agent and the composition of the blast furnace slag before pre-desulfurization.
研究了炉顶渣在含钒钛热金属预脱硫过程中的脱硫能力。由高炉炉渣和 CaO 脱硫剂形成的 CaO-SiO2-MgO-Al2O3-TiO2-VOx 炉顶渣系统可将热金属中的硫从 0.08 wt.% 降至 0.02 wt.%。研究发现，炉渣的再硫化发生在脱硫过程的后期。脱硫渣中的钒钛氧化物均呈酸性。TiO2 和 VOx 在 1623 K 时与碱性氧化物反应生成 CaTiO3 和 MgV2O4，使游离 CaO 减少，不利于炉顶渣脱硫。计算结果表明，顶渣脱硫占总脱硫量的 15%。利用炉渣结构的离子和分子共存理论，可以通过调整脱硫剂的用量和预脱硫前高炉炉渣的成分来提高脱硫效率。
{"title":"Influence of Top Slag Containing TiO2 and VOx on Hot Metal Pre-Desulfurization","authors":"Biwen Yang, Bo Song, Liang Chen, Honghong Sun, Derek O. Northwood, Kristian E. Waters, Hao Ma","doi":"10.3390/met14080910","DOIUrl":"https://doi.org/10.3390/met14080910","url":null,"abstract":"The desulfurization capacity of top slag in the process of pre-desulfurization of hot metal containing vanadium and titanium was researched. The top slag system of CaO-SiO2-MgO-Al2O3-TiO2-VOx that was formed by blast furnace slag and a CaO desulfurization agent reduced the sulfur in hot metal from 0.08 wt.% to 0.02 wt.%. It was found that the resulfurization of the slag happened in the later periods of the desulfurization process. The vanadium–titanium oxides were both acidic in the desulfurization slag. TiO2 and VOx reacted with the basic oxides to form CaTiO3 and MgV2O4 at 1623 K, which reduced free CaO and was not conducive to top slag desulfurization. The results of calculation showed that the top slag desulfurization accounted for 15% of the total desulfurization. Using the ionic and molecule coexistence theory of slag structure, it is shown that the desulfurization efficiency could be enhanced by adjusting both the amount of desulfurization agent and the composition of the blast furnace slag before pre-desulfurization.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"16 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling.
TNM 合金是一种含 βo- 相的 TiAl 合金，由于在使用中经常出现冲击断裂，已不再被用作商用喷气发动机的最后一级涡轮叶片，从而引发了人们对实用 TiAl 合金中是否需要 βo- 相的怀疑。在此，我们对喷气发动机叶片所需的各种 TiAl 合金的实际性能进行了评估，并研究了 βo- 相对其的影响。首先，我们探讨了β-相含量对锻造Ti-43.5Al-xCr和铸造Ti-46.0Al-xCr合金的抗冲击性和可加工性的影响；β-相含量增加时，合金的性能会明显降低。随后，通过改变前者的热处理温度和后者的铬浓度，制备了两种含有和不含β-相的实用TiAl合金--TNM合金和TiAl4822。除了抗冲击性和机加工性能外，蠕变强度也因 βo- 相的存在而显著降低。总之，这些研究结果表明，β-相是实用钛铝合金（尤其是用于喷气发动机叶片的钛铝合金）中不受欢迎的相，因为虽然无序的β-相在高温下很软，但冷却后会转变为明显更脆、更硬的β-相。
{"title":"Detrimental Effects of βo-Phase on Practical Properties of TiAl Alloys","authors":"Toshimitsu Tetsui, Kazuhiro Mizuta","doi":"10.3390/met14080908","DOIUrl":"https://doi.org/10.3390/met14080908","url":null,"abstract":"The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"96 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inclusions are an important parameter affecting the fatigue life of materials. In this paper, the type, size, and quantity of inclusions in bearing steel were quantitatively analyzed using scanning electron microscopy and automatic scanning electron microscopy with an X-ray energy dispersive spectroscopy function. The effects of the inclusion parameters and positions on the rotating bending fatigue properties were analyzed using the rotating bending fatigue test. The results proved that for samples 1 and 2, the inclusions were mainly sulfides, Ti-containing inclusions, and their composite inclusions. For samples 3 and 4, the inclusions were mainly oxides or sulfide–oxide complexes. The number and maximum size of inclusions in sample 2 were relatively small. This was mainly due to the difference in the content of Al, S, and Ca elements in the different samples. The inclusion distance to the surface and the maximum inclusion size had a larger influence on the rotating bending fatigue life in comparison to the inclusion type. Moreover, nitride–oxides had a more detrimental effect on the rotating bending fatigue life as compared to the sulfide–oxide complex inclusions. A model was established on the basis of the inclusion size, depth, and stress by using the Python software. The simulation demonstrated that using five parameters fit well with the experiment results.
夹杂物是影响材料疲劳寿命的一个重要参数。本文利用扫描电子显微镜和带 X 射线能量色散光谱功能的自动扫描电子显微镜对轴承钢中夹杂物的类型、尺寸和数量进行了定量分析。利用旋转弯曲疲劳试验分析了夹杂物参数和位置对旋转弯曲疲劳性能的影响。结果证明，对于样品 1 和 2，夹杂物主要是硫化物、含钛夹杂物及其复合夹杂物。对于样品 3 和 4，夹杂物主要是氧化物或硫化物-氧化物复合物。样品 2 中夹杂物的数量和最大尺寸相对较小。这主要是由于不同样品中 Al、S 和 Ca 元素的含量不同。与夹杂物类型相比，夹杂物到表面的距离和最大夹杂物尺寸对旋转弯曲疲劳寿命的影响更大。此外，与硫化物-氧化物复合夹杂物相比，氮化物-氧化物对旋转弯曲疲劳寿命的影响更大。根据夹杂物的尺寸、深度和应力，利用 Python 软件建立了一个模型。模拟结果表明，使用五个参数与实验结果非常吻合。
{"title":"Influence of Inclusion Parameter and Depth on the Rotating Bending Fatigue Behavior of Bearing Steel","authors":"Lijun Xu, Zhonghua Zhan, Shulan Zhang","doi":"10.3390/met14080907","DOIUrl":"https://doi.org/10.3390/met14080907","url":null,"abstract":"Inclusions are an important parameter affecting the fatigue life of materials. In this paper, the type, size, and quantity of inclusions in bearing steel were quantitatively analyzed using scanning electron microscopy and automatic scanning electron microscopy with an X-ray energy dispersive spectroscopy function. The effects of the inclusion parameters and positions on the rotating bending fatigue properties were analyzed using the rotating bending fatigue test. The results proved that for samples 1 and 2, the inclusions were mainly sulfides, Ti-containing inclusions, and their composite inclusions. For samples 3 and 4, the inclusions were mainly oxides or sulfide–oxide complexes. The number and maximum size of inclusions in sample 2 were relatively small. This was mainly due to the difference in the content of Al, S, and Ca elements in the different samples. The inclusion distance to the surface and the maximum inclusion size had a larger influence on the rotating bending fatigue life in comparison to the inclusion type. Moreover, nitride–oxides had a more detrimental effect on the rotating bending fatigue life as compared to the sulfide–oxide complex inclusions. A model was established on the basis of the inclusion size, depth, and stress by using the Python software. The simulation demonstrated that using five parameters fit well with the experiment results.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration.
{"title":"Effect of Si Addition in NiCrAl Coating on Corrosion in Molten Nitrate Salt","authors":"Thamrongsin Siripongsakul, Patchaporn Kettrakul, Noparat Kanjanaprayut, Piyorose Promdirek","doi":"10.3390/met14080902","DOIUrl":"https://doi.org/10.3390/met14080902","url":null,"abstract":"The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"15 Suppl 1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microstructure degradation and phase transformations are critical concerns in nickel-based superalloys during thermal exposure. Understanding the phase transformation mechanism requires the detailed mapping of the distribution of each phase at different degradation stages and in various precipitation sizes. However, differentiating between phases in large areas, typically on the scale of millimeters and often relying on scanning electron microscopy (SEM) techniques, has traditionally been a challenging task. In this study, we present a novel and efficient phase mapping method that leverages multiple imaging detectors and modes in SEM. This approach allows for the relatively rapid and explicit differentiation and mapping of the distribution of various phases, including MC, M23C6, γ′, and η phases, as demonstrated in a typical superalloy subjected to aging experiments at 800 °C.
微结构降解和相变是镍基超级合金在热暴露过程中的关键问题。要了解相变机制，就必须详细绘制各相在不同降解阶段和不同沉淀尺寸下的分布图。然而，要在大面积区域内区分不同的相，通常需要毫米级的扫描电子显微镜（SEM）技术，这在传统上是一项极具挑战性的任务。在本研究中，我们提出了一种新颖高效的相图绘制方法，该方法利用了扫描电子显微镜中的多种成像探测器和模式。这种方法可以相对快速、清晰地区分和绘制各种相的分布，包括 MC、M23C6、γ′ 和 η 相，在 800 °C 下进行老化实验的典型超级合金中进行了演示。
{"title":"Phase Mapping Using a Combination of Multi-Functional Scanning Electron Microscopy Detectors and Imaging Modes","authors":"Gang Liu, Yonghua Zhao, Shuai Wang","doi":"10.3390/met14080899","DOIUrl":"https://doi.org/10.3390/met14080899","url":null,"abstract":"Microstructure degradation and phase transformations are critical concerns in nickel-based superalloys during thermal exposure. Understanding the phase transformation mechanism requires the detailed mapping of the distribution of each phase at different degradation stages and in various precipitation sizes. However, differentiating between phases in large areas, typically on the scale of millimeters and often relying on scanning electron microscopy (SEM) techniques, has traditionally been a challenging task. In this study, we present a novel and efficient phase mapping method that leverages multiple imaging detectors and modes in SEM. This approach allows for the relatively rapid and explicit differentiation and mapping of the distribution of various phases, including MC, M23C6, γ′, and η phases, as demonstrated in a typical superalloy subjected to aging experiments at 800 °C.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"8 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores the effects of tempering on the precipitation behavior and impact toughness of high-nickel steel. The specimens underwent double quenching at 870 °C and 770 °C, followed by tempering at various temperatures. Advanced characterization techniques including optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to elucidate precipitation phenomena. Additionally, electron backscatter diffraction (EBSD) was employed to assess the misorientation distribution after tempering. Charpy impact tests were performed on specimens tempered at different temperatures to evaluate their toughness. The findings reveal that with increasing tempering temperature, the fraction of low-angle grain boundaries decreases, which correlates positively with enhanced impact toughness. The results demonstrate that tempering at 580 °C optimizes the material’s microstructure, achieving an impact toughness value of approximately 163 J.
{"title":"Optimizing Tempering Parameters to Enhance Precipitation Behavior and Impact Toughness in High-Nickel Steel","authors":"Guojin Sun, Qi Wang","doi":"10.3390/met14080898","DOIUrl":"https://doi.org/10.3390/met14080898","url":null,"abstract":"This study explores the effects of tempering on the precipitation behavior and impact toughness of high-nickel steel. The specimens underwent double quenching at 870 °C and 770 °C, followed by tempering at various temperatures. Advanced characterization techniques including optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to elucidate precipitation phenomena. Additionally, electron backscatter diffraction (EBSD) was employed to assess the misorientation distribution after tempering. Charpy impact tests were performed on specimens tempered at different temperatures to evaluate their toughness. The findings reveal that with increasing tempering temperature, the fraction of low-angle grain boundaries decreases, which correlates positively with enhanced impact toughness. The results demonstrate that tempering at 580 °C optimizes the material’s microstructure, achieving an impact toughness value of approximately 163 J.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"58 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geethapriyan Thangamani, Stefano Felicioni, Elisa Padovano, Sara Biamino, Mariangela Lombardi, Daniele Ugues, Paolo Fino, Federica Bondioli
In recent years, additive manufacturing (AM) has played a significant role in various fashion industries, especially the textile and jewelry manufacturing sectors. This review article delves deeply into the wide range of methods and materials used to make intricately designed jewelry fabrication using the additive manufacturing (AM) process. The Laser Powder Bed Fusion (L-PBF) process is examined for its suitability in achieving complex design and structural integrity in jewelry fabrication even with respect to powder metallurgy methods. Moreover, the review explores the use of precious materials, such as gold, silver, copper, platinum, and their alloys in additive manufacturing. Processing precious materials is challenging due to their high reflectivity and thermal conductivity, which results in poor densification and mechanical properties. To address this issue, the review article proposes three different strategies: (i) adding alloying elements, (ii) coating powder particles, and (iii) using low-wavelength lasers (green or blue). Finally, this review examines crucial post-processing techniques to improve surface quality, robustness, and attractiveness. To conclude, this review emphasizes the potential of combining additive manufacturing (AM) with traditional craftsmanship for creating jewelry, exploring the potential future directions and developments in the field of additive manufacturing (AM) for jewelry fabrication.
{"title":"A Comprehensive Review of Laser Powder Bed Fusion in Jewelry: Technologies, Materials, and Post-Processing with Future Perspective","authors":"Geethapriyan Thangamani, Stefano Felicioni, Elisa Padovano, Sara Biamino, Mariangela Lombardi, Daniele Ugues, Paolo Fino, Federica Bondioli","doi":"10.3390/met14080897","DOIUrl":"https://doi.org/10.3390/met14080897","url":null,"abstract":"In recent years, additive manufacturing (AM) has played a significant role in various fashion industries, especially the textile and jewelry manufacturing sectors. This review article delves deeply into the wide range of methods and materials used to make intricately designed jewelry fabrication using the additive manufacturing (AM) process. The Laser Powder Bed Fusion (L-PBF) process is examined for its suitability in achieving complex design and structural integrity in jewelry fabrication even with respect to powder metallurgy methods. Moreover, the review explores the use of precious materials, such as gold, silver, copper, platinum, and their alloys in additive manufacturing. Processing precious materials is challenging due to their high reflectivity and thermal conductivity, which results in poor densification and mechanical properties. To address this issue, the review article proposes three different strategies: (i) adding alloying elements, (ii) coating powder particles, and (iii) using low-wavelength lasers (green or blue). Finally, this review examines crucial post-processing techniques to improve surface quality, robustness, and attractiveness. To conclude, this review emphasizes the potential of combining additive manufacturing (AM) with traditional craftsmanship for creating jewelry, exploring the potential future directions and developments in the field of additive manufacturing (AM) for jewelry fabrication.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"33 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mathilde Laot, Viviam Marques Pereira, Theo Bakker, Elio d’Agata, Oliver Martin, Murthy Kolluri
Assessing the embrittlement and hardening of reactor pressure vessel steels is critical for the extension of the service lifetime of nuclear power plants. This paper summarises the tensile test results on the irradiation behaviour of realistic VVER-1000 welds from the STRUMAT-LTO project. The welds were irradiated at the HFR (Petten, the Netherlands) to a fluence of up to 1.087 × 1020 n·cm−2, and their irradiation hardening was studied by means of tensile testing. The four grades, with different Mn and Ni contents, show different hardening behaviours. The highest degree of irradiation hardening is observed for the weld that has the highest combined Ni + Mn content. The results show that there is a synergetic effect of Mn and Ni on the irradiation hardening behaviour of the VVER-1000 welds. Besides irradiation hardening, the effectiveness of post-irradiation annealing treatments on the recovery of the tensile properties is studied in the present work. Post-irradiation annealing treatments conducted at 418 °C and at 475 °C proved to be effective for three of the four investigated welds. For the realistic weld with the highest combined Ni + Mn, only the annealing at 475 °C led to the complete recovery of the tensile properties.
{"title":"Investigation of Irradiation Hardening and Effectiveness of Post-Irradiation Annealing on the Recovery of Tensile Properties of VVER-1000 Realistic Welds Irradiated in the LYRA-10 Experiment","authors":"Mathilde Laot, Viviam Marques Pereira, Theo Bakker, Elio d’Agata, Oliver Martin, Murthy Kolluri","doi":"10.3390/met14080887","DOIUrl":"https://doi.org/10.3390/met14080887","url":null,"abstract":"Assessing the embrittlement and hardening of reactor pressure vessel steels is critical for the extension of the service lifetime of nuclear power plants. This paper summarises the tensile test results on the irradiation behaviour of realistic VVER-1000 welds from the STRUMAT-LTO project. The welds were irradiated at the HFR (Petten, the Netherlands) to a fluence of up to 1.087 × 1020 n·cm−2, and their irradiation hardening was studied by means of tensile testing. The four grades, with different Mn and Ni contents, show different hardening behaviours. The highest degree of irradiation hardening is observed for the weld that has the highest combined Ni + Mn content. The results show that there is a synergetic effect of Mn and Ni on the irradiation hardening behaviour of the VVER-1000 welds. Besides irradiation hardening, the effectiveness of post-irradiation annealing treatments on the recovery of the tensile properties is studied in the present work. Post-irradiation annealing treatments conducted at 418 °C and at 475 °C proved to be effective for three of the four investigated welds. For the realistic weld with the highest combined Ni + Mn, only the annealing at 475 °C led to the complete recovery of the tensile properties.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"46 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the influence of corrosion-induced deterioration of the tensile properties of a Mg-1 wt.% Ca alloy on the performance of a coronary artery stent model fabricated using the alloy wire. Finite element analysis was used to determine the change in various characteristics of the model when immersed in a biosimulation aqueous solution (Earle’s Balanced Salt Solution). Results from tensile tests on wires fabricated from the alloy (non-treated versus ultrasound-assisted casting (US)) were used as input to a shape optimisation study of the stent, which aimed at reducing stent strut thickness and minimising corrosion-related parameters such as equivalent plastic strain and residual stress. For each of the characteristics, it was found that the US treatment produced a more desirable result compared to the stents modelled using non-treated material data; for example, the decrease in strut thickness, equivalent plastic strain, and residual stress were each markedly greater, while keeping the stent’s functionality. These results suggest that US-treated Mg-1 wt./wt.% Ca alloy may be promising for fabricating biodegradable coronary artery stents.
本研究探讨了镁-1 wt.% 钙合金的拉伸性能因腐蚀而退化对使用该合金丝制造的冠状动脉支架模型性能的影响。研究采用有限元分析法确定模型浸入生物模拟水溶液（Earle's 平衡盐溶液）后各种特性的变化。用合金制造的金属丝（未处理与超声辅助铸造（US））的拉伸试验结果被用作支架形状优化研究的输入，该研究旨在减少支架支柱厚度，并最大限度地降低腐蚀相关参数，如等效塑性应变和残余应力。研究发现，与使用未处理材料数据建模的支架相比，US 处理对每种特性都产生了更理想的结果；例如，在保持支架功能的同时，支架厚度、等效塑性应变和残余应力的减小幅度都明显增大。这些结果表明，经 US 处理的 Mg-1 wt./wt.% Ca 合金有望用于制造可生物降解的冠状动脉支架。
{"title":"Impact of Corrosion on Tensile Properties of a Mg Alloy in a Finite Element Model of a Coronary Artery Stent Coupled with Geometry Optimization","authors":"Inês V. Gomes, José L. Alves, Hélder Puga","doi":"10.3390/met14080885","DOIUrl":"https://doi.org/10.3390/met14080885","url":null,"abstract":"This study investigated the influence of corrosion-induced deterioration of the tensile properties of a Mg-1 wt.% Ca alloy on the performance of a coronary artery stent model fabricated using the alloy wire. Finite element analysis was used to determine the change in various characteristics of the model when immersed in a biosimulation aqueous solution (Earle’s Balanced Salt Solution). Results from tensile tests on wires fabricated from the alloy (non-treated versus ultrasound-assisted casting (US)) were used as input to a shape optimisation study of the stent, which aimed at reducing stent strut thickness and minimising corrosion-related parameters such as equivalent plastic strain and residual stress. For each of the characteristics, it was found that the US treatment produced a more desirable result compared to the stents modelled using non-treated material data; for example, the decrease in strut thickness, equivalent plastic strain, and residual stress were each markedly greater, while keeping the stent’s functionality. These results suggest that US-treated Mg-1 wt./wt.% Ca alloy may be promising for fabricating biodegradable coronary artery stents.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"79 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review explores the critical role of powder quality in metal 3D printing and the importance of effective powder recycling strategies. It covers various metal 3D printing technologies, in particular Selective Laser Melting, Electron Beam Melting, Direct Energy Deposition, and Binder Jetting, and analyzes the impact of powder characteristics on the final part properties. This review highlights key challenges associated with powder recycling, including maintaining consistent particle size and shape, managing contamination, and mitigating degradation effects from repeated use, such as wear, fragmentation, and oxidation. Furthermore, it explores various recycling techniques, such as sieving, blending, plasma spheroidization, and powder conditioning, emphasizing their role in restoring powder quality and enabling reuse.
{"title":"The Challenges and Advances in Recycling/Re-Using Powder for Metal 3D Printing: A Comprehensive Review","authors":"Alex Lanzutti, Elia Marin","doi":"10.3390/met14080886","DOIUrl":"https://doi.org/10.3390/met14080886","url":null,"abstract":"This review explores the critical role of powder quality in metal 3D printing and the importance of effective powder recycling strategies. It covers various metal 3D printing technologies, in particular Selective Laser Melting, Electron Beam Melting, Direct Energy Deposition, and Binder Jetting, and analyzes the impact of powder characteristics on the final part properties. This review highlights key challenges associated with powder recycling, including maintaining consistent particle size and shape, managing contamination, and mitigating degradation effects from repeated use, such as wear, fragmentation, and oxidation. Furthermore, it explores various recycling techniques, such as sieving, blending, plasma spheroidization, and powder conditioning, emphasizing their role in restoring powder quality and enabling reuse.","PeriodicalId":18461,"journal":{"name":"Metals","volume":"75 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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