Pub Date : 1984-01-01DOI: 10.1179/030716984803274828
R. Whittle, V. Scott
AbstractTufftriding a selection of austenitic alloys produces in each a reaction zone consisting of three layers. A thin, hard layer, composed essentially of oxide, is formed on the specimen surface. Beneath this is a carbonitride of the γ', M4(CN) type, with a low carbon/nitrogen ratio. The innermost layer has a much higher carbon concentration, which reaches ∼2%. Wear behaviour, evaluated without lubrication using a pin-on-disc machine, shows a transition from mild wear to severe wear once the applied load exceeds a critical value. Mild wear is associated with the tribological properties of the outer layer. In the severe-wear regime, the wear rate is higher by approximately an order of magnitude; under these conditions the oxide is removed fairly quickly, and wear is controlled by the properties of the underlying carbonitride. The results are compared with those obtained previously for untreated and nitrided alloys, and it is concluded that Tufftriding shows promise as a method of improving the tribolog...
{"title":"Sliding–wear evaluation of Tufftrided austenitic alloys","authors":"R. Whittle, V. Scott","doi":"10.1179/030716984803274828","DOIUrl":"https://doi.org/10.1179/030716984803274828","url":null,"abstract":"AbstractTufftriding a selection of austenitic alloys produces in each a reaction zone consisting of three layers. A thin, hard layer, composed essentially of oxide, is formed on the specimen surface. Beneath this is a carbonitride of the γ', M4(CN) type, with a low carbon/nitrogen ratio. The innermost layer has a much higher carbon concentration, which reaches ∼2%. Wear behaviour, evaluated without lubrication using a pin-on-disc machine, shows a transition from mild wear to severe wear once the applied load exceeds a critical value. Mild wear is associated with the tribological properties of the outer layer. In the severe-wear regime, the wear rate is higher by approximately an order of magnitude; under these conditions the oxide is removed fairly quickly, and wear is controlled by the properties of the underlying carbonitride. The results are compared with those obtained previously for untreated and nitrided alloys, and it is concluded that Tufftriding shows promise as a method of improving the tribolog...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"76 1","pages":"392-398"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79683875","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: 10.1179/030716984803274774
J. Monaghan, A. Torrance
AbstractThe forces and stresses associated with the final stages of die-corner fillout during a closed-die forging operation are difficult to predict. This problem was investigated for the forging of high-conductivity copper under plane-strain conditions, using an upper-bound method. The choice of suitable deforming regions and the most appropriate velocity fields for these regions was made with the aid of the visioplasticity technique. Theoretical results based on the upper-bound solutions were found to be in close agreement with the results of a series of forging experiments. A simplified upper-bound expression was found to give solutions which should be sufficiently accurate for engineering problems.
{"title":"Plane-strain coining","authors":"J. Monaghan, A. Torrance","doi":"10.1179/030716984803274774","DOIUrl":"https://doi.org/10.1179/030716984803274774","url":null,"abstract":"AbstractThe forces and stresses associated with the final stages of die-corner fillout during a closed-die forging operation are difficult to predict. This problem was investigated for the forging of high-conductivity copper under plane-strain conditions, using an upper-bound method. The choice of suitable deforming regions and the most appropriate velocity fields for these regions was made with the aid of the visioplasticity technique. Theoretical results based on the upper-bound solutions were found to be in close agreement with the results of a series of forging experiments. A simplified upper-bound expression was found to give solutions which should be sufficiently accurate for engineering problems.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"54 1","pages":"20-28"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83257716","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: 10.1179/030716984803274675
R. Nicholson
AbstractThe interfacial structures between 2·25Cr–1 Mo steel and Inconel 182 weld metal have been studied in the as-welded condition and after aging at temperatures between 630 and 700°C for times up to 6000 h. Examination of the as-welded specimens revealed a band of martensite ∼0·5 to ∼50 μm wide between the steel and the weld metal. During aging, precipitates developed in this band and led to arrays of interfacial carbides which showed two morphologies, depending on the initial width of the martensite band. Single lines of coarse carbides were associated with narrow bands, and finer precipitates were distributed within the wider martensite bands. Initially, the interfacial precipitates formed readily between 630 and 700°C, but on further aging at temperatures >675°C the precipitates dissolved. The effects of changing the welding conditions and weld metal composition on the development of the interfacial precipitates are considered. In comparison with nickel-based transition joints examined after longte...
{"title":"Effect of aging on interfacial structures of nickel-based transition joints","authors":"R. Nicholson","doi":"10.1179/030716984803274675","DOIUrl":"https://doi.org/10.1179/030716984803274675","url":null,"abstract":"AbstractThe interfacial structures between 2·25Cr–1 Mo steel and Inconel 182 weld metal have been studied in the as-welded condition and after aging at temperatures between 630 and 700°C for times up to 6000 h. Examination of the as-welded specimens revealed a band of martensite ∼0·5 to ∼50 μm wide between the steel and the weld metal. During aging, precipitates developed in this band and led to arrays of interfacial carbides which showed two morphologies, depending on the initial width of the martensite band. Single lines of coarse carbides were associated with narrow bands, and finer precipitates were distributed within the wider martensite bands. Initially, the interfacial precipitates formed readily between 630 and 700°C, but on further aging at temperatures >675°C the precipitates dissolved. The effects of changing the welding conditions and weld metal composition on the development of the interfacial precipitates are considered. In comparison with nickel-based transition joints examined after longte...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"86 1","pages":"115-124"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79964501","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: 10.1179/030716984803275115
A. Fletcher, V. G. Gibson, J. Gonzáles
AbstractA comparison has been made between the experimentally determined values of roll force and torque produced during the hot rolling of an En 2 steel slab and those predicted by calculation. The latter were obtained using a fourth-order Runge–Kutta technique, originally developed by Alexander. An experimental programme was also carried out, to obtain values of the compressive flow stress, the coefficient of friction between slab and roll, and the temperature distribution in the material during rolling, to provide data for use in the roll-force calculations. The mean level of discrepancy obtained was 6·5% (standard deviation 17%) in the case of roll force and 8·7% (25%) in the case of roll torque, but most of these discrepancies can be accounted/or by uncertainties in the data used in the calculations. It is concluded, therefore, that this method of calculation could provide a realistic prediction of roll force and torque, provided the data used in the calculation are known sufficiently accurately.
{"title":"Prediction of roll force and torque during hot flat rolling of En 2 steel","authors":"A. Fletcher, V. G. Gibson, J. Gonzáles","doi":"10.1179/030716984803275115","DOIUrl":"https://doi.org/10.1179/030716984803275115","url":null,"abstract":"AbstractA comparison has been made between the experimentally determined values of roll force and torque produced during the hot rolling of an En 2 steel slab and those predicted by calculation. The latter were obtained using a fourth-order Runge–Kutta technique, originally developed by Alexander. An experimental programme was also carried out, to obtain values of the compressive flow stress, the coefficient of friction between slab and roll, and the temperature distribution in the material during rolling, to provide data for use in the roll-force calculations. The mean level of discrepancy obtained was 6·5% (standard deviation 17%) in the case of roll force and 8·7% (25%) in the case of roll torque, but most of these discrepancies can be accounted/or by uncertainties in the data used in the calculations. It is concluded, therefore, that this method of calculation could provide a realistic prediction of roll force and torque, provided the data used in the calculation are known sufficiently accurately.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":" 43","pages":"156-166"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91412045","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: 10.1179/030716984803274288
A. Chambers, D. Whittaker
AbstractIn this paper the machinability of forging steel grades, microalloyed with vanadium for precipitation hardening and used in the air-cooled condition, are compared with those of hardened and tempered steel grades. Standard laboratory tests, employing both high-speed-steel and cemented carbide tooling, have been used. In most instances, microalloyed steel proved to be at least as machinable as hardened and tempered steel grades of similar strength level. However, because of a higher dependence of machinability on workpiece hardness, microalloyed steels may have inferior machinability to hardened and tempered alloy steels, at tensile-strength levels above 1000 MN m−2. This higher dependence on workpiece hardness has been investigated using a range of experimental techniques and a tentative mechanism has been proposed. Finally, compositional adjustments have been proposed, which might improve the machinability of microalloyed steels and thus eliminate this one potential problem area.
{"title":"Machining characteristics of microalloyed forging steels","authors":"A. Chambers, D. Whittaker","doi":"10.1179/030716984803274288","DOIUrl":"https://doi.org/10.1179/030716984803274288","url":null,"abstract":"AbstractIn this paper the machinability of forging steel grades, microalloyed with vanadium for precipitation hardening and used in the air-cooled condition, are compared with those of hardened and tempered steel grades. Standard laboratory tests, employing both high-speed-steel and cemented carbide tooling, have been used. In most instances, microalloyed steel proved to be at least as machinable as hardened and tempered steel grades of similar strength level. However, because of a higher dependence of machinability on workpiece hardness, microalloyed steels may have inferior machinability to hardened and tempered alloy steels, at tensile-strength levels above 1000 MN m−2. This higher dependence on workpiece hardness has been investigated using a range of experimental techniques and a tentative mechanism has been proposed. Finally, compositional adjustments have been proposed, which might improve the machinability of microalloyed steels and thus eliminate this one potential problem area.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"27 1","pages":"323-333"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90605248","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: 10.1179/030716984803274981
A. Singer
AbstractA new process, simultaneous spray peening (SSP), is described which comprises the spray deposition of metals together with simultaneous shot peening. This combined incremental operation allows either thick or thin deposits to be made in ferrous or non-ferrous metals. The deposits are hot worked and densified during the process so improving their properties compared with more conventional spray deposits. An additional advantage is that the inherent residual tensile stresses of spray deposition are counter-balanced by the compressive stresses caused by peening. By control of the simultaneous peening operation it is shown that the residual stresses in SSP deposits can be maintained at any required positive or negative level. Examples and structures are shown of SSP products made from gas-atomized melts, by arc spray, and by plasma spray.
{"title":"Simultaneous spray deposition and peening of metals (SSP)","authors":"A. Singer","doi":"10.1179/030716984803274981","DOIUrl":"https://doi.org/10.1179/030716984803274981","url":null,"abstract":"AbstractA new process, simultaneous spray peening (SSP), is described which comprises the spray deposition of metals together with simultaneous shot peening. This combined incremental operation allows either thick or thin deposits to be made in ferrous or non-ferrous metals. The deposits are hot worked and densified during the process so improving their properties compared with more conventional spray deposits. An additional advantage is that the inherent residual tensile stresses of spray deposition are counter-balanced by the compressive stresses caused by peening. By control of the simultaneous peening operation it is shown that the residual stresses in SSP deposits can be maintained at any required positive or negative level. Examples and structures are shown of SSP products made from gas-atomized melts, by arc spray, and by plasma spray.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"82 1","pages":"99-104"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85598502","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: 10.1179/030716984803274819
D. W. Livesey, C. Sellars
AbstractPlane-strain compression tests have been carried out over the temperature range 700–1000°C on three Cu–Ni alloys containing 34, 43, and 68%Ni. The stress-strain curves at strain rates of 1 and 10 s−1 all show a peak in flow stress, followed by a fall to a steady–state value, which is characteristic of the occurrence of dynamic recrystallization; the extent of the fall is, however, significantly increased by deformational heating. At 900°C and above, static recrystallization occurs in times of ≲ 1 s, leading to dislocation-free grain structures, even in quenched samples. Lubricated hot extrusion of the alloys gives pressure–distance curves similar in form to those obtained for steels. Running pressures can be calculated with reasonable accuracy using data on heat-transfer and friction conditions derived previously from hot-extrusion studies on steels.
{"title":"Hot-deformation characteristics and extrusion of copper–nickel alloys","authors":"D. W. Livesey, C. Sellars","doi":"10.1179/030716984803274819","DOIUrl":"https://doi.org/10.1179/030716984803274819","url":null,"abstract":"AbstractPlane-strain compression tests have been carried out over the temperature range 700–1000°C on three Cu–Ni alloys containing 34, 43, and 68%Ni. The stress-strain curves at strain rates of 1 and 10 s−1 all show a peak in flow stress, followed by a fall to a steady–state value, which is characteristic of the occurrence of dynamic recrystallization; the extent of the fall is, however, significantly increased by deformational heating. At 900°C and above, static recrystallization occurs in times of ≲ 1 s, leading to dislocation-free grain structures, even in quenched samples. Lubricated hot extrusion of the alloys gives pressure–distance curves similar in form to those obtained for steels. Running pressures can be calculated with reasonable accuracy using data on heat-transfer and friction conditions derived previously from hot-extrusion studies on steels.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"60 1","pages":"149-155"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88324774","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: 10.1179/030716984803274558
F. Heisterkamp, K. Hulka
AbstractThe weldability of a 0·5Ni-0·15Nb steel has been investigated using welding-simulation procedures, laboratory testing, pipe production welding of spiral and V-O pipes, and manual and automatic field welding. It has been shown that the weld heat-affected zones exhibit a tough bainitic microstructure over a wide range of cooling rates encountered in pipe welding. The optimum weld-metal microstructure and properties are obtained with a Mo-B-Ti wire are enhanced by the diffusion of Nb from the baseplate. The excellent strength and toughness of the weldments can therefore be matched with the baseplate properties of X65 to X75 pipe obtained with this Ni-Nb steel. Freedom from cold cracking and relatively low maximum hardness values are additional features of the weldments.
摘要采用焊接模拟、室内试验、螺旋管和v型管的管道生产焊接以及现场手工和自动焊接等方法，研究了0.5 ni -0 15Nb钢的可焊性。结果表明，在较大的冷却速率范围内，焊接热影响区呈现出坚韧的贝氏体组织。钼-硼-钛焊丝的最佳焊缝组织和性能是通过从基板中扩散铌而得到的。因此，焊接件的优异强度和韧性可以与用这种Ni-Nb钢获得的X65至X75管的底板性能相匹配。免于冷裂和相对较低的最大硬度值是焊件的附加特性。
{"title":"Low-carbon Mn-Ni-Nb steel: Part 2 Weldability","authors":"F. Heisterkamp, K. Hulka","doi":"10.1179/030716984803274558","DOIUrl":"https://doi.org/10.1179/030716984803274558","url":null,"abstract":"AbstractThe weldability of a 0·5Ni-0·15Nb steel has been investigated using welding-simulation procedures, laboratory testing, pipe production welding of spiral and V-O pipes, and manual and automatic field welding. It has been shown that the weld heat-affected zones exhibit a tough bainitic microstructure over a wide range of cooling rates encountered in pipe welding. The optimum weld-metal microstructure and properties are obtained with a Mo-B-Ti wire are enhanced by the diffusion of Nb from the baseplate. The excellent strength and toughness of the weldments can therefore be matched with the baseplate properties of X65 to X75 pipe obtained with this Ni-Nb steel. Freedom from cold cracking and relatively low maximum hardness values are additional features of the weldments.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"200 1","pages":"545-549"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86834397","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: 10.1179/030716984803275197
M. Pontremoli, P. Bufalini, A. Aprile, C. Jannone
AbstractThe future demand for high-grade pipeline materials (API X80 and higher) calls for the development of steels with microstructures showing acicular phases (acicular ferrite, bainite, and martensite-austenite (M A) constituent). A systematic investigation has heen made (of the mechanical properties and microstructures exhibited hy a wide range of controlled-rolled plates (of final thickness 18 mm) of various chemical compositions, produced on a laboratory scale. Low-carhon (∼ 0·06% C) boron-free and boron-containing steels have been examined, as has a boron steel with a Imrer carbon content (0–02% C). The boron-free steels (carbon equivalent ≤0.46%) always exhihited a polygonal ferrite matrix with a dispersed phase consisting mainly of M A constituent, while the horoncontaining steels (carhon equivalent ≤0.40%) invariahly showed an acicular matrix with a lower volume fraction of finely dispersed M A island. Quantitative relationships are ohtained hetween the volume fractions of the microstructural c...
{"title":"Development of grade API X80 pipeline steel plates produced by controlled rolling","authors":"M. Pontremoli, P. Bufalini, A. Aprile, C. Jannone","doi":"10.1179/030716984803275197","DOIUrl":"https://doi.org/10.1179/030716984803275197","url":null,"abstract":"AbstractThe future demand for high-grade pipeline materials (API X80 and higher) calls for the development of steels with microstructures showing acicular phases (acicular ferrite, bainite, and martensite-austenite (M A) constituent). A systematic investigation has heen made (of the mechanical properties and microstructures exhibited hy a wide range of controlled-rolled plates (of final thickness 18 mm) of various chemical compositions, produced on a laboratory scale. Low-carhon (∼ 0·06% C) boron-free and boron-containing steels have been examined, as has a boron steel with a Imrer carbon content (0–02% C). The boron-free steels (carbon equivalent ≤0.46%) always exhihited a polygonal ferrite matrix with a dispersed phase consisting mainly of M A constituent, while the horoncontaining steels (carhon equivalent ≤0.40%) invariahly showed an acicular matrix with a lower volume fraction of finely dispersed M A island. Quantitative relationships are ohtained hetween the volume fractions of the microstructural c...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"41 1","pages":"504-514"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81515629","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: 10.1179/030716984803274648
M. Zaidi, T. Sheppard
AbstractAlmost all aluminium alloys that are to be produced in wrought form are subjected to an homogenization sequence involving a high-temperature soak and controlled cooling operation. The resulting structure is modified and in this communication it is shown that varying structures resulting from controlled homogenization produce differing reactions in the annealing operation subsequent to hot rolling. It is shown that the homogenization sequence may be designed such that recrystallization may be either retarded or enhanced and it is suggested that this preheat should be designed as part of the process to achieve optimum product properties.
{"title":"Effect of hightemperature soak and cooling rate on recrystallization behaviour of tvvo Al–Mg alloys (AA 5252 and AA 5454)","authors":"M. Zaidi, T. Sheppard","doi":"10.1179/030716984803274648","DOIUrl":"https://doi.org/10.1179/030716984803274648","url":null,"abstract":"AbstractAlmost all aluminium alloys that are to be produced in wrought form are subjected to an homogenization sequence involving a high-temperature soak and controlled cooling operation. The resulting structure is modified and in this communication it is shown that varying structures resulting from controlled homogenization produce differing reactions in the annealing operation subsequent to hot rolling. It is shown that the homogenization sequence may be designed such that recrystallization may be either retarded or enhanced and it is suggested that this preheat should be designed as part of the process to achieve optimum product properties.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"2 1","pages":"313-319"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80637218","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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