cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6857804
title: Effects of water salinity and organomineral fertilization on leaf composition and production in Passiflora edulis

description: ABSTRACT An experiment was undertaken in Remígio County, Paraíba State, Brazil, from July 2013 to May 2014, in order to evaluate the effects of saline water irrigation, bovine biofertilizer, and potassium type on soil salinity, leaf macronutrient composition, and production of yellow passion fruit cv. BRS Gigante Amarelo. Treatments were distributed in randomized blocks, arranged in a 2 × 2 × 2 factorial design, with reference to electrical conductivity of the water (0.35 and 4.00 dS m-1), soil with and without bovine biofertilizer, and application of potassium chloride as a conventional treatment (KCl) and in an organic polymer-coated form, supplied monthly. Bovine biofertilizer was diluted in non-saline water (proportion, 50%) and applied via water at a volume of 6 L plant-1 one day before transplanting, and then every 90 days. The combination of saline water with bovine biofertilizer raised soil salinity to a similar proportion when comparing saline water and conventional potassium chloride with saline water and polymer-coated potassium chloride. The increase in water saline concentrations associated with both types of potassium chloride and with bovine biofertilizer elevated soil salinity from non-saline to saline. On starting to flower, plants of cv. BRS Gigante Amarelo were deficient in macronutrients other than nitrogen and potassium, but nonetheless produced fruits of an adequate mass for the consumer market.
DOI: 10.6084/m9.figshare.6857804.v1
title: Effects of water salinity and organomineral fertilization on leaf composition and production in Passiflora edulis

description: ABSTRACT An experiment was undertaken in Remígio County, Paraíba State, Brazil, from July 2013 to May 2014, in order to evaluate the effects of saline water irrigation, bovine biofertilizer, and potassium type on soil salinity, leaf macronutrient composition, and production of yellow passion fruit cv. BRS Gigante Amarelo. Treatments were distributed in randomized blocks, arranged in a 2 × 2 × 2 factorial design, with reference to electrical conductivity of the water (0.35 and 4.00 dS m-1), soil with and without bovine biofertilizer, and application of potassium chloride as a conventional treatment (KCl) and in an organic polymer-coated form, supplied monthly. Bovine biofertilizer was diluted in non-saline water (proportion, 50%) and applied via water at a volume of 6 L plant-1 one day before transplanting, and then every 90 days. The combination of saline water with bovine biofertilizer raised soil salinity to a similar proportion when comparing saline water and conventional potassium chloride with saline water and polymer-coated potassium chloride. The increase in water saline concentrations associated with both types of potassium chloride and with bovine biofertilizer elevated soil salinity from non-saline to saline. On starting to flower, plants of cv. BRS Gigante Amarelo were deficient in macronutrients other than nitrogen and potassium, but nonetheless produced fruits of an adequate mass for the consumer market.
DOI: 10.6084/m9.figshare.6857798
title: Obtaininglow alloy steels with different Ni contents and similar microstructures and mechanical properties

description: ABSTRACT Low alloy steels are used in many applications in the oil and gas industry. The addition of Ni in these steels improves their low temperature fracture toughness and hardenability, with a low penalty on weldability. However, ISO 15156-2 standard restricts Ni content up to a 1 wt% limit, requiring additional and expensive tests if higher Ni steels are to be used. This limit is based on the hypothesis that higher contents of Ni may negatively affect Sulfide Stress Cracking (SSC) resistance in sour service applications. On the other hand, several investigators have concluded that SSC resistance depends on microstructure and hardness rather than Ni content. The 1 wt% Ni limit imposed by ISO 15156-2 is controversial, as recently pointed out by other authors. This work aims to develop alloys and heat treatments tailored to obtain the same microstructure and hardness in steels with different Ni contents (from 0 to 5 wt %), therefore leaving Ni content as the main variable. This will allow, in a future stage of the project, to study the effect of Ni on the SSC crack propagation kinetics. Transformation temperaturesof the alloys were measured with differential scanning calorimetry (DSC). Characterization of the as-quenched samples confirmed a fully martensite microstructure. Tempering of the samples allowed obtaining hardness values near 22 HRC. Microstructure was evaluated with optical and scanning electron microscope and hardness measurements. Tensile tests were performed to evaluate mechanical properties as a function of Ni content.
DOI: 10.6084/m9.figshare.6857795
title: Influence of defects on the irreversible phase transition in the Fe-Pd doped with Co and Mn

description: ABSTRACT The appearance of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys, which develops at lower temperatures than the thermoelastic martensitic transition, deteriorates the shape memory properties. In a previous work performed in Fe70Pd30, it was shown that a reduction in defects density reduces the non thermoelastic FCT-BCT transformation temperature. In the present work, the influence of quenched-in-defects upon the intensity and temperature of the thermoelastic martensitic (FCC-FCT) and the non thermoelastic (FCT-BCT) transitions in Fe-Pd doped with Co and Mn is studied. Differential scanning calorimetric and mechanical spectroscopy studies demonstrate that a reduction in the dislocation density the stability range of the FCC-FCT reversible transformation in Fe67Pd30Co3 and Fe66.8Pd30.7Mn2.5 ferromagnetic shape memory alloys.
DOI: 10.6084/m9.figshare.6857795.v1
title: Influence of defects on the irreversible phase transition in the Fe-Pd doped with Co and Mn

description: ABSTRACT The appearance of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys, which develops at lower temperatures than the thermoelastic martensitic transition, deteriorates the shape memory properties. In a previous work performed in Fe70Pd30, it was shown that a reduction in defects density reduces the non thermoelastic FCT-BCT transformation temperature. In the present work, the influence of quenched-in-defects upon the intensity and temperature of the thermoelastic martensitic (FCC-FCT) and the non thermoelastic (FCT-BCT) transitions in Fe-Pd doped with Co and Mn is studied. Differential scanning calorimetric and mechanical spectroscopy studies demonstrate that a reduction in the dislocation density the stability range of the FCC-FCT reversible transformation in Fe67Pd30Co3 and Fe66.8Pd30.7Mn2.5 ferromagnetic shape memory alloys.
DOI: 10.6084/m9.figshare.6857798.v1
title: Obtaininglow alloy steels with different Ni contents and similar microstructures and mechanical properties

description: ABSTRACT Low alloy steels are used in many applications in the oil and gas industry. The addition of Ni in these steels improves their low temperature fracture toughness and hardenability, with a low penalty on weldability. However, ISO 15156-2 standard restricts Ni content up to a 1 wt% limit, requiring additional and expensive tests if higher Ni steels are to be used. This limit is based on the hypothesis that higher contents of Ni may negatively affect Sulfide Stress Cracking (SSC) resistance in sour service applications. On the other hand, several investigators have concluded that SSC resistance depends on microstructure and hardness rather than Ni content. The 1 wt% Ni limit imposed by ISO 15156-2 is controversial, as recently pointed out by other authors. This work aims to develop alloys and heat treatments tailored to obtain the same microstructure and hardness in steels with different Ni contents (from 0 to 5 wt %), therefore leaving Ni content as the main variable. This will allow, in a future stage of the project, to study the effect of Ni on the SSC crack propagation kinetics. Transformation temperaturesof the alloys were measured with differential scanning calorimetry (DSC). Characterization of the as-quenched samples confirmed a fully martensite microstructure. Tempering of the samples allowed obtaining hardness values near 22 HRC. Microstructure was evaluated with optical and scanning electron microscope and hardness measurements. Tensile tests were performed to evaluate mechanical properties as a function of Ni content.
DOI: 10.6084/m9.figshare.6857792
title: Effect of sub-zero treatment on the microstructure and hardness of high-chromium white cast iron

description: ABSTRACT The effect of the sub-zero treatment temperature on the transformation of retained austenite to martensite in two high chromium white cast irons (ASTM A532 Class II Type B) was studied. The sub-zero treatment applied to each alloy in the as cast condition was performed at -40, -65 and -180 ° C for 10 minutes; after the holding time was completed the samples were cooled to room temperature. The microstructure of the as cast condition was analyzed by optical microscopy (LOM) and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis was also performed with the aim to identify the microconstituents initially present in each alloy. The metallographic characterization of the specimens subjected to sub-zero treatment was performed by optical microscopy. Furthermore, Brinell hardness was measured in the as cast and sub-zero treated samples. The alloys studied have important differences in chemical composition, mainly in the molybdenum and copper content, which mainly determine its microstructure. The results showed an increase in the hardness of both alloys with decreasing treatment temperature; which is due to the fact that the amount of retained austenite transformed to martensite increases as the martensite finish temperature (Mf) is reached. It was also observed that a higher molybdenum content produces a metastable austenitic matrix in the as cast samples. Furthermore, the effect of Mo and other alloying elements substantially stabilizes the austenite, obtaining low amounts of martensite after the sub-zero treatment, even at -180 ° C.
DOI: 10.6084/m9.figshare.6857792.v1
title: Effect of sub-zero treatment on the microstructure and hardness of high-chromium white cast iron

description: ABSTRACT The effect of the sub-zero treatment temperature on the transformation of retained austenite to martensite in two high chromium white cast irons (ASTM A532 Class II Type B) was studied. The sub-zero treatment applied to each alloy in the as cast condition was performed at -40, -65 and -180 ° C for 10 minutes; after the holding time was completed the samples were cooled to room temperature. The microstructure of the as cast condition was analyzed by optical microscopy (LOM) and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis was also performed with the aim to identify the microconstituents initially present in each alloy. The metallographic characterization of the specimens subjected to sub-zero treatment was performed by optical microscopy. Furthermore, Brinell hardness was measured in the as cast and sub-zero treated samples. The alloys studied have important differences in chemical composition, mainly in the molybdenum and copper content, which mainly determine its microstructure. The results showed an increase in the hardness of both alloys with decreasing treatment temperature; which is due to the fact that the amount of retained austenite transformed to martensite increases as the martensite finish temperature (Mf) is reached. It was also observed that a higher molybdenum content produces a metastable austenitic matrix in the as cast samples. Furthermore, the effect of Mo and other alloying elements substantially stabilizes the austenite, obtaining low amounts of martensite after the sub-zero treatment, even at -180 ° C.
DOI: 10.6084/m9.figshare.6857789
title: Evaluation of using acetylene as carbon source in the carburization of steels

description: ABSTRACT The effect of using acetylene as a carbon source in the gas carburization of AISI/SAE 8620 steel was evaluated in this work. For this purpose, a gaseous carburizing system was designed and manufactured with the following characteristics: controlled production of a carburant gaseous atmosphere, inert and hermetic isothermal reaction zone and carbon/oxygen probe for the control of carbon potential (Cp) during the carburization cycle. An atmosphere composed of synthetic endothermic gas with composition of 40%H2, 40%N2 and 20%CO and constant flow of 100 cm3/min and acetylene variations with flows of 40cm3/min, 65cm3/min and 85cm3/min was used. These gases were injected into the reactor at 900°C and held for three hours. The acetylene gas was selected as the carbon-enriching agent in the atmosphere, due to the high decomposition ratios of these molecules and the low tendency to develop polymerization reactions. The characterization of the carburized steels was performed by optical microscopy (OM), optical emission spectrometry (OES) and Vickers microhardness tests (HV). The results show that there is a great efficiency and control in the carbon transfer during the carburization cycle, favoring the optimization of resources and processing times.
DOI: 10.6084/m9.figshare.6857786
title: Mechanical properties estimation of AISI 304L stainless steel sheet using SPT

description: ABSTRACT The mechanical characterization of materials by small specimen testing has growing interest in Structural Engineering. Small Punch Test (SPT) is applied to estimate mechanical properties of samples that can be extracted from components or structures without affecting service operation. In this paper the development of the test device is reported, constructed according to the CWA 15627: 2007 recommendation. Stainless steel AISI 304L was selected to estimate tensile mechanical properties. The results obtained are compared with standard tensile tests results. We analyze the experimental parameters involved and compare the analytical expressions available in the literature with those indicated by the reference recommendation. Finally, we have implemented finite element simulation of load-displacement curves. Based on the results of this work, a method for evaluating the effect of specimen thickness on the estimation of mechanical properties is proposed.
DOI: 10.6084/m9.figshare.6857789.v1
title: Evaluation of using acetylene as carbon source in the carburization of steels

description: ABSTRACT The effect of using acetylene as a carbon source in the gas carburization of AISI/SAE 8620 steel was evaluated in this work. For this purpose, a gaseous carburizing system was designed and manufactured with the following characteristics: controlled production of a carburant gaseous atmosphere, inert and hermetic isothermal reaction zone and carbon/oxygen probe for the control of carbon potential (Cp) during the carburization cycle. An atmosphere composed of synthetic endothermic gas with composition of 40%H2, 40%N2 and 20%CO and constant flow of 100 cm3/min and acetylene variations with flows of 40cm3/min, 65cm3/min and 85cm3/min was used. These gases were injected into the reactor at 900°C and held for three hours. The acetylene gas was selected as the carbon-enriching agent in the atmosphere, due to the high decomposition ratios of these molecules and the low tendency to develop polymerization reactions. The characterization of the carburized steels was performed by optical microscopy (OM), optical emission spectrometry (OES) and Vickers microhardness tests (HV). The results show that there is a great efficiency and control in the carbon transfer during the carburization cycle, favoring the optimization of resources and processing times.
DOI: 10.6084/m9.figshare.6857783
title: Study of hot-workability of titanium alloys through hot-torsion testing and its application to the optimization of forging and extrusion processes

description: ABSTRACT In the development of hot metal forming, the metallic products must comply with the requirements imposed by current standards. In some cases, the required microstructure can only be obtained through thermomechanical processing. With titanium and its alloys, small ranges of good workability are an additional difficulty. In this work the hot-workability of aeronautical quality titanium alloys was studied through hot torsion and compression testing. The results were used to define the m teri l’s pl stic behaviour seeking to optimize forging and extrusion operating parameters, such as temperature, strain rate, area reduction, etc. Additionally, different processing routes were simulated through hot-torsion testing and the resulting microstructures were analysed and successfully compared to the current standards. At the same time, the minimum amount of area reduction required to obtain such microstructure was determined. The results of hot-workability testing plus the information registered in full-scale Grade 2 Ti extrusion tests were used to simulate different extrusion processes with FEA. To calibrate the FE model it was also necess ry to ev lu te the illet’s temper ture evolution through the press’s feeding system nd the behaviour of the available lubricants. The FE model proved to be accurate to predict the required extrusion force for the tested geometries. This way, the feasibility of extruding different sections was determined and the operating parameters were optimized to maintain the extrusion pressure within operative limits as well as to obtain the m teri l’s properties nd microstructures required in current st nd rds.
DOI: 10.6084/m9.figshare.6857786.v1
title: Mechanical properties estimation of AISI 304L stainless steel sheet using SPT

description: ABSTRACT The mechanical characterization of materials by small specimen testing has growing interest in Structural Engineering. Small Punch Test (SPT) is applied to estimate mechanical properties of samples that can be extracted from components or structures without affecting service operation. In this paper the development of the test device is reported, constructed according to the CWA 15627: 2007 recommendation. Stainless steel AISI 304L was selected to estimate tensile mechanical properties. The results obtained are compared with standard tensile tests results. We analyze the experimental parameters involved and compare the analytical expressions available in the literature with those indicated by the reference recommendation. Finally, we have implemented finite element simulation of load-displacement curves. Based on the results of this work, a method for evaluating the effect of specimen thickness on the estimation of mechanical properties is proposed.
DOI: 10.6084/m9.figshare.6857780
title: Splitting phenomenon of martensitic transformation in a F82H reduced neutron activation steel

description: ABSTRACT One of the most promising solutions to global energy supply is nuclear fusion. This process, which is implemented in nuclear fusion reactors (from which one of the first designs was the Tokamak), involves deuterium-tritium plasmas at very high temperature, confined in vacuum chambers of toroidal shape under the influence of strong magnetic fields. The hostile conditions underwent by structural components of these reactors drives the development of new materials with metallurgical properties adapted to these conditions. In particular, the so-called reduced activation martensitic-ferritic steels (R.A.F.M.’s) are strong candidates for constructing these reactors components, due its excellent physical properties. In this contribution 6 samples of the alloy F82H, a steel belonging to the R.A.F.M. group, were analyzed. They were extracted from a plate normalized at a temperature of 1040ºC for 38 minutes and tempered at 750ºC for 60 minutes (as- received condition). The specimens were tested in a high resolution dilatometer Bähr model DIL 805-A. The samples were heated at a controlled rate of 5ºC/min. up to 1050ºC, followed by an isothermal holding at the same temperature for 15 minutes, to finally be cooled continuously to room temperature at different rates: 1.5, 2, 3, 5, 10 and 50 ºC/min. The dilatometric curves obtained after the tests showed the presence of a splitting phenomenon of the martensitic transformation at low cooling rates. By simple mathematical models, based on experimental data, curves giving the fraction of transformed phase (austenite-martensita) and their respective temporal derivatives as a function of temperature were obtained for each cooling rate. High resolution images of the tested samples were also obtained using a FEG-SEM, as a complement of metallographic analysis.
DOI: 10.6084/m9.figshare.6857780.v1
title: Splitting phenomenon of martensitic transformation in a F82H reduced neutron activation steel

description: ABSTRACT One of the most promising solutions to global energy supply is nuclear fusion. This process, which is implemented in nuclear fusion reactors (from which one of the first designs was the Tokamak), involves deuterium-tritium plasmas at very high temperature, confined in vacuum chambers of toroidal shape under the influence of strong magnetic fields. The hostile conditions underwent by structural components of these reactors drives the development of new materials with metallurgical properties adapted to these conditions. In particular, the so-called reduced activation martensitic-ferritic steels (R.A.F.M.’s) are strong candidates for constructing these reactors components, due its excellent physical properties. In this contribution 6 samples of the alloy F82H, a steel belonging to the R.A.F.M. group, were analyzed. They were extracted from a plate normalized at a temperature of 1040ºC for 38 minutes and tempered at 750ºC for 60 minutes (as- received condition). The specimens were tested in a high resolution dilatometer Bähr model DIL 805-A. The samples were heated at a controlled rate of 5ºC/min. up to 1050ºC, followed by an isothermal holding at the same temperature for 15 minutes, to finally be cooled continuously to room temperature at different rates: 1.5, 2, 3, 5, 10 and 50 ºC/min. The dilatometric curves obtained after the tests showed the presence of a splitting phenomenon of the martensitic transformation at low cooling rates. By simple mathematical models, based on experimental data, curves giving the fraction of transformed phase (austenite-martensita) and their respective temporal derivatives as a function of temperature were obtained for each cooling rate. High resolution images of the tested samples were also obtained using a FEG-SEM, as a complement of metallographic analysis.