Statistics of extreme values (SEV) and generalized Pareto distribution (GPD) are adopted to predict the maximum inclusion size in 40Cr structural steel, and the fatigue strength was estimated according to the obtained maximum inclusion size. The estimated results were compared with the experimental results obtained in rotating bending fatigue testing, where all failure-relevant inclusions of the present study were quantitatively analyzed with respect to area (square root of the projected inclusion area). Both the estimation results are consistent with the experimental results. Furthermore, a suitable maximum inclusion size equal to the prior austenite grain size is proposed for the material manufacturing process.
{"title":"Maximum Inclusion Size Evaluation and Fatigue Strength Analysis of 40Cr Structural Steel","authors":"Yingxin Zhao, Aiguo Zhao","doi":"10.1155/2022/4566471","DOIUrl":"https://doi.org/10.1155/2022/4566471","url":null,"abstract":"Statistics of extreme values (SEV) and generalized Pareto distribution (GPD) are adopted to predict the maximum inclusion size in 40Cr structural steel, and the fatigue strength was estimated according to the obtained maximum inclusion size. The estimated results were compared with the experimental results obtained in rotating bending fatigue testing, where all failure-relevant inclusions of the present study were quantitatively analyzed with respect to \u0000 \u0000 \u0000 \u0000 area\u0000 \u0000 \u0000 \u0000 (square root of the projected inclusion area). Both the estimation results are consistent with the experimental results. Furthermore, a suitable maximum inclusion size equal to the prior austenite grain size is proposed for the material manufacturing process.","PeriodicalId":18220,"journal":{"name":"Material Design & Processing Communications","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79258157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AISI 4130 steels have been used in several engineering applications, although presenting limited hardenability in conventional heat treatments. This contribution is aimed at determining the final hardness and reciprocating wear coefficient of friction (COF) after a given laser surface treatment (LST) with or without a carbon coating (C). The results indicated that the bare (B, without coating) condition produced a deeper case depth as a result of the carbon-rich plasma shielding. The observed microstructural features in the cases B and C showed martensite transformation and cementite formation; the latter is entirely in the C condition. Simple calculations using Rosenthal’s formalism indicate a high cooling rate, estimated as 32 ′ 280°C/s 40 μm below the irradiated surface and a heat-affected zone bounded by the austenite locus. The hardness near to the surface was higher in case C than in case B, but the overall final hardness is more pronounced when the surface is bare (B) due to plasma shielding. On the other hand, the final COF was very low in the C case (0.1) compared to the B condition (0.6).
{"title":"Reduced Coefficient of Friction of Laser Surface Hardened AISI 4130 Steel Substrates","authors":"M. R. Furlani, S. Carvalho, R. Siqueira, M. Lima","doi":"10.1155/2022/7541853","DOIUrl":"https://doi.org/10.1155/2022/7541853","url":null,"abstract":"AISI 4130 steels have been used in several engineering applications, although presenting limited hardenability in conventional heat treatments. This contribution is aimed at determining the final hardness and reciprocating wear coefficient of friction (COF) after a given laser surface treatment (LST) with or without a carbon coating (C). The results indicated that the bare (B, without coating) condition produced a deeper case depth as a result of the carbon-rich plasma shielding. The observed microstructural features in the cases B and C showed martensite transformation and cementite formation; the latter is entirely in the C condition. Simple calculations using Rosenthal’s formalism indicate a high cooling rate, estimated as 32\u0000 \u0000 \u0000 \u0000 \u0000 ′\u0000 \u0000 \u0000 \u0000 280°C/s 40 μm below the irradiated surface and a heat-affected zone bounded by the austenite locus. The hardness near to the surface was higher in case C than in case B, but the overall final hardness is more pronounced when the surface is bare (B) due to plasma shielding. On the other hand, the final COF was very low in the C case (0.1) compared to the B condition (0.6).","PeriodicalId":18220,"journal":{"name":"Material Design & Processing Communications","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84049024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Linardatos, K. Velissarakos, I. Valais, G. Fountos, N. Kalyvas, C. Michail
Scintillators with high light yield (LY) values are of interest for medical imaging applications, in harsh environments, nondestructive testing (NDT), etc. CeBr3 has a LY of 60000 photons per MeV, a value much higher than other efficient materials, such as Lu3Al5O12:Ce (25000 photons/MeV); thus, its X-ray detection properties would be of interest to be examined for medical imaging applications. The X-ray detection and absorption properties of a single crystal CeBr3 sample along with the compatibility of its produced light with various optoelectronic sensors were examined. In this study, the quantum detection (QDE) and the energy absorption efficiency (EAE) of CeBr3 were calculated. The findings were compared with data for 10 × 10 × 10 m m 3 Lu3Al5O12:Ce and CaF2:Eu single crystals. The measured optical spectrum produced by CeBr3 was well correlated with the spectral response of commercial optical sensors, yielding spectral matching higher than 93% for various photocathodes, e.g., GaAs (94%), E-S20 (95%), and bialkali and multialkali (95-97%), as well as with flat panel position-sensitive photomultipliers (95-99%). The energy absorption properties of CeBr3 were found higher than those of Lu3Al5O12:Ce and CaF2:Eu for X-ray tube voltages greater than 100 kVp. The quantum detection efficiency was 100% across the examined energy range. Even though CeBr3 is hygroscopic and has a mediocre 5.1 g/cm3 density, the QDE, EAE, and spectral correlation results are promising for medical imaging applications.
具有高光产率(LY)值的闪烁体对医疗成像应用，恶劣环境，无损检测(NDT)等都很感兴趣。CeBr3具有60000光子/MeV的LY，远高于其他高效材料，如Lu3Al5O12:Ce(25000光子/MeV);因此，它的x射线探测特性将是医学成像应用中值得研究的。研究了单晶CeBr3样品的x射线探测和吸收特性，以及其产生的光与各种光电传感器的兼容性。本研究计算了CeBr3的量子探测(QDE)和能量吸收效率(EAE)。结果与10 × 10 × 10 m m 3 Lu3Al5O12:Ce和CaF2:Eu单晶的数据进行了比较。CeBr3产生的测量光谱与商用光学传感器的光谱响应具有良好的相关性，对于各种光电阴极，如GaAs (94%)， E-S20(95%)，双碱和多碱(95-97%)，以及平板位置敏感光电倍增管(95-99%)，光谱匹配率均高于93%。当x射线管电压大于100 kVp时，CeBr3的能量吸收性能高于Lu3Al5O12:Ce和CaF2:Eu。在被检测的能量范围内，量子探测效率为100%。尽管CeBr3具有吸湿性，密度一般为5.1 g/cm3，但QDE、EAE和光谱相关结果在医学成像应用方面很有前景。
{"title":"Cerium Bromide Single-Crystal X-Ray Detection and Spectral Compatibility Assessment with Various Optical Sensors","authors":"D. Linardatos, K. Velissarakos, I. Valais, G. Fountos, N. Kalyvas, C. Michail","doi":"10.1155/2022/7008940","DOIUrl":"https://doi.org/10.1155/2022/7008940","url":null,"abstract":"Scintillators with high light yield (LY) values are of interest for medical imaging applications, in harsh environments, nondestructive testing (NDT), etc. CeBr3 has a LY of 60000 photons per MeV, a value much higher than other efficient materials, such as Lu3Al5O12:Ce (25000 photons/MeV); thus, its X-ray detection properties would be of interest to be examined for medical imaging applications. The X-ray detection and absorption properties of a single crystal CeBr3 sample along with the compatibility of its produced light with various optoelectronic sensors were examined. In this study, the quantum detection (QDE) and the energy absorption efficiency (EAE) of CeBr3 were calculated. The findings were compared with data for \u0000 \u0000 10\u0000 ×\u0000 10\u0000 ×\u0000 10\u0000 \u0000 m\u0000 \u0000 \u0000 m\u0000 \u0000 \u0000 3\u0000 \u0000 \u0000 \u0000 Lu3Al5O12:Ce and CaF2:Eu single crystals. The measured optical spectrum produced by CeBr3 was well correlated with the spectral response of commercial optical sensors, yielding spectral matching higher than 93% for various photocathodes, e.g., GaAs (94%), E-S20 (95%), and bialkali and multialkali (95-97%), as well as with flat panel position-sensitive photomultipliers (95-99%). The energy absorption properties of CeBr3 were found higher than those of Lu3Al5O12:Ce and CaF2:Eu for X-ray tube voltages greater than 100 kVp. The quantum detection efficiency was 100% across the examined energy range. Even though CeBr3 is hygroscopic and has a mediocre 5.1 g/cm3 density, the QDE, EAE, and spectral correlation results are promising for medical imaging applications.","PeriodicalId":18220,"journal":{"name":"Material Design & Processing Communications","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81408412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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