Pub Date : 1984-01-01DOI: 10.1179/030716984803274477
F. Weinberg
AbstractThe extrusion of Pb and Pb–1Sb has been investigated at very low compressive pressures in the temperature range 25°–150°C. The results indicate that a threshold pressure is required for significant extrusion to occur. The threshold pressure is higher in Pb–1Sb than in Pb, and increases with decreasing temperature. The results are related to the problem of lead being extruded over very long periods of time from a breached container filled with lead. It is concluded that no significant extrusion of lead would occur.
{"title":"Extrusion of lead at low compressive pressures","authors":"F. Weinberg","doi":"10.1179/030716984803274477","DOIUrl":"https://doi.org/10.1179/030716984803274477","url":null,"abstract":"AbstractThe extrusion of Pb and Pb–1Sb has been investigated at very low compressive pressures in the temperature range 25°–150°C. The results indicate that a threshold pressure is required for significant extrusion to occur. The threshold pressure is higher in Pb–1Sb than in Pb, and increases with decreasing temperature. The results are related to the problem of lead being extruded over very long periods of time from a breached container filled with lead. It is concluded that no significant extrusion of lead would occur.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"519 1","pages":"29-33"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77202160","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803275188
G. W. Meetham
AbstractThis paper commences with a brief description of superalloys and their applications. Trace elements which may be present are classified, and their effects, adverse or beneficial, are briefly summarized. More detailed discussion of effects and mechanisms will be provided in the other papers in this issue. Some elements may be beneficial in small concentrations, but harmful in larger ones. In many cases, the effects of individual elements have been sufficiently quantified to allow specification limits to be set, but further work is required on the effects of different elemental combinations, on analysis at low concentrations, and on the mechanisms by which some trace element effects operate. With respect to the control of trace elements, it is necessary to specify not only the purity of the metallic raw materials, but also the purity of consumable manufacturing-process materials.
{"title":"Trace elements in superalloys–an overview","authors":"G. W. Meetham","doi":"10.1179/030716984803275188","DOIUrl":"https://doi.org/10.1179/030716984803275188","url":null,"abstract":"AbstractThis paper commences with a brief description of superalloys and their applications. Trace elements which may be present are classified, and their effects, adverse or beneficial, are briefly summarized. More detailed discussion of effects and mechanisms will be provided in the other papers in this issue. Some elements may be beneficial in small concentrations, but harmful in larger ones. In many cases, the effects of individual elements have been sufficiently quantified to allow specification limits to be set, but further work is required on the effects of different elemental combinations, on analysis at low concentrations, and on the mechanisms by which some trace element effects operate. With respect to the control of trace elements, it is necessary to specify not only the purity of the metallic raw materials, but also the purity of consumable manufacturing-process materials.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"31 1","pages":"414-418"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78642308","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274909
R. Reuben, T. N. Baker
AbstractThree vacuum-melted steels based on a composition 0·05–0·08C–4·0Mn, with and without a niobium addition, were controlled rolled to a finish-rolling temperature in the range 700−950°C and air cooled to room temperature. Measurements were made of the ferrite mean free distance, which was correlated with strength and toughness data. Additional qualitative information on precipitation was also gathered. Finished material showed a wide range of strength and toughness. Proof stresses were in the range 610–930 MNm−2 and ductile-brittle (55 J) transition temperatures varied between −90 and + 30°C. The properties of a given material seem to be governed by the carbon and niobium contents, as well as by the ferrite mean free distance. Up to 0·08%C, very high strength coupled with adequate toughness seemed to be obtained by retaining as much carbon in solution as possible, particularly by avoiding cementite precipitation. A fine NbC precipitation appeared to have a beneficial effect on toughness.
{"title":"Mechanical properties and microstructure of lovv-carbon-4% manganese steels","authors":"R. Reuben, T. N. Baker","doi":"10.1179/030716984803274909","DOIUrl":"https://doi.org/10.1179/030716984803274909","url":null,"abstract":"AbstractThree vacuum-melted steels based on a composition 0·05–0·08C–4·0Mn, with and without a niobium addition, were controlled rolled to a finish-rolling temperature in the range 700−950°C and air cooled to room temperature. Measurements were made of the ferrite mean free distance, which was correlated with strength and toughness data. Additional qualitative information on precipitation was also gathered. Finished material showed a wide range of strength and toughness. Proof stresses were in the range 610–930 MNm−2 and ductile-brittle (55 J) transition temperatures varied between −90 and + 30°C. The properties of a given material seem to be governed by the carbon and niobium contents, as well as by the ferrite mean free distance. Up to 0·08%C, very high strength coupled with adequate toughness seemed to be obtained by retaining as much carbon in solution as possible, particularly by avoiding cementite precipitation. A fine NbC precipitation appeared to have a beneficial effect on toughness.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"11 1","pages":"6-13"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74339864","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274576
R. Drew, W. B. Muir, W. M. Williams
AbstractAnnealing of cold-worked plain carbon and high-strength low-alloy steels may be monitored in situ by measurement of differential electrical resistivity using an alternating current method. The change in room-temperature resistivity is about 4% for steels given a prior cold reduction of 80%. Recovery and recrystallization are distinguishable as two separate stages in these materials; the onset and end point of recrystallization can be identified during the progress of annealing. It was also possible to observe changes in resistivity resulting from grain growth. However, the changes could not be quantified since grain-growth rates were extremely slow in the steels studied.
{"title":"Differential resistivity as a means of monitoring annealing in steels","authors":"R. Drew, W. B. Muir, W. M. Williams","doi":"10.1179/030716984803274576","DOIUrl":"https://doi.org/10.1179/030716984803274576","url":null,"abstract":"AbstractAnnealing of cold-worked plain carbon and high-strength low-alloy steels may be monitored in situ by measurement of differential electrical resistivity using an alternating current method. The change in room-temperature resistivity is about 4% for steels given a prior cold reduction of 80%. Recovery and recrystallization are distinguishable as two separate stages in these materials; the onset and end point of recrystallization can be identified during the progress of annealing. It was also possible to observe changes in resistivity resulting from grain growth. However, the changes could not be quantified since grain-growth rates were extremely slow in the steels studied.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"33 1","pages":"550-554"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80878644","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803275034
R. Kießling
AbstractThe subject of stainless steels was chosen by the author for this lecture because of Dr Hatfield's pioneering work in this field. He feels, however, that today these steels are under intense competition; the interface between producer and consumer is given particular attention. The importance attached to this aspect of the producers' activities means that the problems under consideration fall as much in the field of market research as of physical metallurgy – it is necessary for suppliers to think as consumers rather than as producers. The competition from other materials with respect to physical properties is not very severe, but that in terms of economic considerations is strong, especially in view of the current overcapacity of the steel industry and the increasing prevalence of trade restrictions. A very brief review is given of contemporary stainless steels, together with a more detailed discussion of duplex austenitic–ferritic steels, which also furnish an example of the need for close coope...
{"title":"31st Hatfield Memorial Lecture: Stainless steels – materials in competition","authors":"R. Kießling","doi":"10.1179/030716984803275034","DOIUrl":"https://doi.org/10.1179/030716984803275034","url":null,"abstract":"AbstractThe subject of stainless steels was chosen by the author for this lecture because of Dr Hatfield's pioneering work in this field. He feels, however, that today these steels are under intense competition; the interface between producer and consumer is given particular attention. The importance attached to this aspect of the producers' activities means that the problems under consideration fall as much in the field of market research as of physical metallurgy – it is necessary for suppliers to think as consumers rather than as producers. The competition from other materials with respect to physical properties is not very severe, but that in terms of economic considerations is strong, especially in view of the current overcapacity of the steel industry and the increasing prevalence of trade restrictions. A very brief review is given of contemporary stainless steels, together with a more detailed discussion of duplex austenitic–ferritic steels, which also furnish an example of the need for close coope...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"72 1","pages":"169-180"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88420350","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803275232
A. V. Bromley, R. H. Parker
AbstractThe stringent demands of producers of Ni-based superalloys set lower permissible levels of deleterious trace elements than those that are normally considered significant by the geologist or the extractive metallurgist. The classification of metallic elements as siderophile, chalcophile, and/or lithophile is found to be a good general guide, as the most harmful superalloy trace elements have strongly chalcophile characteristics, i.e. they are concentrated in sulphides. Ore associations of the major superalloy metals Ni, Co, Cr, Mo, Al, and Ti are reviewed, and it is suggested that only in the case of lateritic Ni and Co ores is any form of ore source selection likely to alleviate problems associated with deleterious trace elements. In all other cases, the problems are passed on to the extractive metallurgist, whose product purity is reviewed from the point of view of the trace elements Sb, As, Bi, Cd, Ga, In, Pb, Mg, Se, Ag, Te, Tl, Sn, and Zn. The purity of carbonyl and some electrolytic Ni seems ...
{"title":"Sources of trace elements in primary raw materials used in production of superalloys","authors":"A. V. Bromley, R. H. Parker","doi":"10.1179/030716984803275232","DOIUrl":"https://doi.org/10.1179/030716984803275232","url":null,"abstract":"AbstractThe stringent demands of producers of Ni-based superalloys set lower permissible levels of deleterious trace elements than those that are normally considered significant by the geologist or the extractive metallurgist. The classification of metallic elements as siderophile, chalcophile, and/or lithophile is found to be a good general guide, as the most harmful superalloy trace elements have strongly chalcophile characteristics, i.e. they are concentrated in sulphides. Ore associations of the major superalloy metals Ni, Co, Cr, Mo, Al, and Ti are reviewed, and it is suggested that only in the case of lateritic Ni and Co ores is any form of ore source selection likely to alleviate problems associated with deleterious trace elements. In all other cases, the problems are passed on to the extractive metallurgist, whose product purity is reviewed from the point of view of the trace elements Sb, As, Bi, Cd, Ga, In, Pb, Mg, Se, Ag, Te, Tl, Sn, and Zn. The purity of carbonyl and some electrolytic Ni seems ...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"31 1","pages":"419-427"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88533790","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274792
R. Whittle, V. Scott
AbstractThe nitriding behaviour of a number of austenitic alloys was investigated for the temperature range 550–850°C. The maximum response to nitriding, as recorded by weight gain and thickness measurements of the nitride layer, occurred between 660 and 750°C. After an initial, faster rate of nitriding during the first few hours of treatment, the reaction followed parabolic kinetics. With most alloys, the nitride formed a compact layer, essentially composed of M4N, at temperatures up to and including 750°C, although at 850°C unreacted metal remained in the surface regions. An exception to this was a high-nickel (∼ 20%) alloy, in which substantial unreacted metal was found at all nitriding temperatures. The role of different alloying elements is discussed in relation to nitriding performance. A selected nitriding treatment is applied to each austenitic alloy, and the resulting unlubricated wear behaviour evaluated using a pin-on-disc wear machine. A transition from mild to severe wear is identified in tre...
{"title":"Sliding-vvear evaluation of nitrided austenitic alloys","authors":"R. Whittle, V. Scott","doi":"10.1179/030716984803274792","DOIUrl":"https://doi.org/10.1179/030716984803274792","url":null,"abstract":"AbstractThe nitriding behaviour of a number of austenitic alloys was investigated for the temperature range 550–850°C. The maximum response to nitriding, as recorded by weight gain and thickness measurements of the nitride layer, occurred between 660 and 750°C. After an initial, faster rate of nitriding during the first few hours of treatment, the reaction followed parabolic kinetics. With most alloys, the nitride formed a compact layer, essentially composed of M4N, at temperatures up to and including 750°C, although at 850°C unreacted metal remained in the surface regions. An exception to this was a high-nickel (∼ 20%) alloy, in which substantial unreacted metal was found at all nitriding temperatures. The role of different alloying elements is discussed in relation to nitriding performance. A selected nitriding treatment is applied to each austenitic alloy, and the resulting unlubricated wear behaviour evaluated using a pin-on-disc wear machine. A transition from mild to severe wear is identified in tre...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"135 1","pages":"231-241"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90960207","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274594
M. Islam, W. Wallace
AbstractThe results of an investigation on the effects of long retrogression times of up to 4 h at 180 and 200°C, and short times of up 10 5 min at 240, 260, and 280°C, on the yield strength, electrical conductivity, and stress-corrosion-crack growth resistance of 7475 T6 aluminium alloy are presented. One optimum retrogression time to provide T6 strength and T73 electrical conductivity was selected for each temperature investigated and was applied to double-cantilever-beam (DCB) stress-corrosion-crack growth specimens. The results show that stress-corrosioncrack growth rates in retrogressed and reaged material are comparable to those in T73 material. Moreover, the 0·2% yield strengths, obtained from specimens machined from the broken DCB specimens, are also above the T6 design-strength level.
{"title":"Stresscorrosion-rack grovvth behaviour of 7475 T6 retrogressed and reaged aluminium alloy","authors":"M. Islam, W. Wallace","doi":"10.1179/030716984803274594","DOIUrl":"https://doi.org/10.1179/030716984803274594","url":null,"abstract":"AbstractThe results of an investigation on the effects of long retrogression times of up to 4 h at 180 and 200°C, and short times of up 10 5 min at 240, 260, and 280°C, on the yield strength, electrical conductivity, and stress-corrosion-crack growth resistance of 7475 T6 aluminium alloy are presented. One optimum retrogression time to provide T6 strength and T73 electrical conductivity was selected for each temperature investigated and was applied to double-cantilever-beam (DCB) stress-corrosion-crack growth specimens. The results show that stress-corrosioncrack growth rates in retrogressed and reaged material are comparable to those in T73 material. Moreover, the 0·2% yield strengths, obtained from specimens machined from the broken DCB specimens, are also above the T6 design-strength level.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"11 1","pages":"320-322"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87155019","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274387
C. S. Wright, A. Wronski, M. M. Rebbeek
AbstractHardness and compressive strength, Young's modulus, bend strength, and fracture toughness were measured in wrought and commercially sintered T42 high-speed steel. After identical heat treatments, no significant differences were found between wrought and sintered materials in hardness (800–1010 HV50), Young's modulus (∼220 GN m−2), or fracture toughness (9−18 MN m−3/2). The four-point bend strengths in the wrought material were slightly higher in specimens cut longitudinal to the working direction than in transverse specimens (1·3–2·4 GN m−2), and both were markedly superior in strength to the sintered material (1·0–1·2 GN m−2). For three-point bend tests with laboratory-sintered material, the stresses for brittle fracture were in the range 1·9–3·0 GN m−2, a level comparable to the wrought specimens. Wrought material contained carbide stringers with a scattering of large Me carbides, whereas in the sintered material pores and incomplete bonding could be detected, albeit infrequently. Fracture initi...
摘要:测定了T42高速钢的硬度、抗压强度、杨氏模量、弯曲强度和断裂韧性。经过相同的热处理，锻造材料和烧结材料在硬度(800-1010 HV50)、杨氏模量(~ 220 GN m−2)或断裂韧性(9 - 18 MN m−3/2)方面没有显著差异。变形后材料的四点弯曲强度在纵向(1·3 ~·4 GN m−2)略高于横向(1·3 ~·4 GN m−2)，且均明显优于烧结材料(1·0 ~ 1·2 GN m−2)。在实验室烧结材料的三点弯曲试验中，脆性断裂的应力范围为1.9 - 3.0 GN m−2，与变形试样的水平相当。锻造材料中含有碳化物条纹，并有大量Me碳化物的散射，而在烧结材料中可以检测到孔隙和不完全结合，尽管不常见。骨折initi……
{"title":"Strength and toughness of T42 high-speed steel","authors":"C. S. Wright, A. Wronski, M. M. Rebbeek","doi":"10.1179/030716984803274387","DOIUrl":"https://doi.org/10.1179/030716984803274387","url":null,"abstract":"AbstractHardness and compressive strength, Young's modulus, bend strength, and fracture toughness were measured in wrought and commercially sintered T42 high-speed steel. After identical heat treatments, no significant differences were found between wrought and sintered materials in hardness (800–1010 HV50), Young's modulus (∼220 GN m−2), or fracture toughness (9−18 MN m−3/2). The four-point bend strengths in the wrought material were slightly higher in specimens cut longitudinal to the working direction than in transverse specimens (1·3–2·4 GN m−2), and both were markedly superior in strength to the sintered material (1·0–1·2 GN m−2). For three-point bend tests with laboratory-sintered material, the stresses for brittle fracture were in the range 1·9–3·0 GN m−2, a level comparable to the wrought specimens. Wrought material contained carbide stringers with a scattering of large Me carbides, whereas in the sintered material pores and incomplete bonding could be detected, albeit infrequently. Fracture initi...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"30 1","pages":"181-188"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90597003","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}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274440
F. Vodopivec, M. Gabrovšek, M. Kmetič, A. Rodic
AbstractVarious steels were rolled using several passes, and the resulting microstructures, precipitation of AlN and NbC, and mechanical properties were investigated. Below a certain critical temperature, interpass recrystallization does not occur completely following the first pass. The volumefraction of unrecrystallized austenite initially increases rapidly, but then decreases gradually as the rolling temperature is lowered. The amount of AlN and NbC precipitation does not appear to be related to the fraction of unrecrystallized austenite. It is proposed that the cause of incomplete recrystallization is the recovery substructure present in austenite grains which, because of their coarse size, do not recrystallize after the first pass. The incomplete interpass recrystallization produces a duplex microstructure, giving the steel a deformation anisotropy.
{"title":"Interpass recrystallization of austenite in some steels during rolling","authors":"F. Vodopivec, M. Gabrovšek, M. Kmetič, A. Rodic","doi":"10.1179/030716984803274440","DOIUrl":"https://doi.org/10.1179/030716984803274440","url":null,"abstract":"AbstractVarious steels were rolled using several passes, and the resulting microstructures, precipitation of AlN and NbC, and mechanical properties were investigated. Below a certain critical temperature, interpass recrystallization does not occur completely following the first pass. The volumefraction of unrecrystallized austenite initially increases rapidly, but then decreases gradually as the rolling temperature is lowered. The amount of AlN and NbC precipitation does not appear to be related to the fraction of unrecrystallized austenite. It is proposed that the cause of incomplete recrystallization is the recovery substructure present in austenite grains which, because of their coarse size, do not recrystallize after the first pass. The incomplete interpass recrystallization produces a duplex microstructure, giving the steel a deformation anisotropy.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"24 1","pages":"481-488"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90150225","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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