Grain size characteristics, mechanical properties, and corrosion resistance of Cu-10%Ni alloy heat treated at three different temperatures and times were investigated and compared with the synthesized alloy. Mechanical properties such as UTS, ductility, hardness, and impact strength were determined. An optical metallurgical microscope was used to examine the structural properties. ImageJ software was also used to measure the grain size distribution of the alloys. The corrosion behaviour of the produced Cu-10%Ni alloys is analyzed by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS). After corrosion testing, the surface morphology of the exposed samples is analyzed by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy. The corrosion rate of precipitate strengthened Cu-10%Ni alloy decreases and ultimate tensile strength, ductility, and hardness increase as the average grain size distribution decreases. The non-heat treated Cu-10%Ni alloy showed a peak value of corrosion rate and average grain size, but a lower value of mechanical properties. An increase in residual stress follows an increase in grain size distribution, which lowers the strength and increases corrosion rates due to more active sites. The research outcome has enabled the improvement of the mechanical and corrosion properties of Cu-10%Ni alloys as a component for marine and automobile applications.
{"title":"GRAIN SIZE EVOLUTION, MECHANICAL AND CORROSION BEHAVIOUR OF PRECIPITATE STRENGTHENED Cu-Ni ALLOY","authors":"C. Nwaeju, Amarachukwu Eboh, F.O. Edoziuno","doi":"10.36547/ams.28.4.1609","DOIUrl":"https://doi.org/10.36547/ams.28.4.1609","url":null,"abstract":"Grain size characteristics, mechanical properties, and corrosion resistance of Cu-10%Ni alloy heat treated at three different temperatures and times were investigated and compared with the synthesized alloy. Mechanical properties such as UTS, ductility, hardness, and impact strength were determined. An optical metallurgical microscope was used to examine the structural properties. ImageJ software was also used to measure the grain size distribution of the alloys. The corrosion behaviour of the produced Cu-10%Ni alloys is analyzed by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS). After corrosion testing, the surface morphology of the exposed samples is analyzed by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy. The corrosion rate of precipitate strengthened Cu-10%Ni alloy decreases and ultimate tensile strength, ductility, and hardness increase as the average grain size distribution decreases. The non-heat treated Cu-10%Ni alloy showed a peak value of corrosion rate and average grain size, but a lower value of mechanical properties. An increase in residual stress follows an increase in grain size distribution, which lowers the strength and increases corrosion rates due to more active sites. The research outcome has enabled the improvement of the mechanical and corrosion properties of Cu-10%Ni alloys as a component for marine and automobile applications.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45985044","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}
S. Mustofa, M. Dani, P. Parikin, T. Sudiro, B. Hermanto, D. R. Adhika, A. Insani, S. Syahbuddin, T. Hino, C. A. Huang
58Fe17Cr25Ni austenite stainless steel has been fabricated using metal powder through sintering with a spark plasma at temperatures of 900 and 950°C for 5 minutes. High purity Fe, Ni and Cr powders were used as materials for this steel. Before sintering, the powder was mixed in a milling equipment which was processed for 5 hours, then it is formed into a coin by pressing it under a load of 25 tons. High resolution powder neutron diffractometer was used for identifying the crystal structure in the 58Fe17Cr25Ni austenitic stainless steel. The sintering process at temperatures of 900C and 950°C generally forms microstructure having matrix of equiaxed austenite grains, with a crystal structure of face-centered cubic which included in the Fm3m space group. Some particles with high Cr content, a'-Cr, are distributed in all austenite grains. The austenite grains seen in the 58Fe17Cr25Niaustenitic stainless steel sintered at 900°C are twin grains. Dislocations, slip planes and bands are also existed in those grains. These defects are expected to decrease with increasing sintering temperatures up to 950° C. This change was followed by the appearance of air bubbles and sub-grains as the dominant sub-structures in the 58Fe17Cr25Ni austenitic stainless steel sintered at 950°C.
{"title":"HRPD and TEM Study of P/M 58Fe17Cr25Ni Austenitic Stainless Steel Synthesized by Spark Plasma Sintering","authors":"S. Mustofa, M. Dani, P. Parikin, T. Sudiro, B. Hermanto, D. R. Adhika, A. Insani, S. Syahbuddin, T. Hino, C. A. Huang","doi":"10.36547/ams.28.4.1548","DOIUrl":"https://doi.org/10.36547/ams.28.4.1548","url":null,"abstract":"58Fe17Cr25Ni austenite stainless steel has been fabricated using metal powder through sintering with a spark plasma at temperatures of 900 and 950°C for 5 minutes. High purity Fe, Ni and Cr powders were used as materials for this steel. Before sintering, the powder was mixed in a milling equipment which was processed for 5 hours, then it is formed into a coin by pressing it under a load of 25 tons. High resolution powder neutron diffractometer was used for identifying the crystal structure in the 58Fe17Cr25Ni austenitic stainless steel. The sintering process at temperatures of 900C and 950°C generally forms microstructure having matrix of equiaxed austenite grains, with a crystal structure of face-centered cubic which included in the Fm3m space group. Some particles with high Cr content, a'-Cr, are distributed in all austenite grains. The austenite grains seen in the 58Fe17Cr25Niaustenitic stainless steel sintered at 900°C are twin grains. Dislocations, slip planes and bands are also existed in those grains. These defects are expected to decrease with increasing sintering temperatures up to 950° C. This change was followed by the appearance of air bubbles and sub-grains as the dominant sub-structures in the 58Fe17Cr25Ni austenitic stainless steel sintered at 950°C.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46979535","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}
Metal additive manufacturing (AM) technology is growing up as a technology. Although up today slower and less reliable than traditional production methods, AM systems are showing to be very successful when producing parts with unconventional topologies or in small quantities. In addition, it is showing its capability to produce components with chemical compositions which should not be realized with standard production processes. In this paper some examples are reported of magnetic materials specifically designed for AM. In this work, powder of FeSi electric steel, with 6.5 wt.% Si content is considered to produce samples by AM. Aim of this paper is to investigate the microstructural and texture evolution of FeSi steels, with 6.5% Si, following annealing heat treatment, with the aim of identifying the conditions under which it could be possible to obtain the best magnetization behavior of the alloys.
{"title":"ADDITIVE MANUFACTURING: A NEW CONCEPT FOR END USERS. THE CASE OF MAGNETIC MATERIALS","authors":"A. Di schino, G. Stornelli","doi":"10.36547/ams.28.4.1648","DOIUrl":"https://doi.org/10.36547/ams.28.4.1648","url":null,"abstract":"Metal additive manufacturing (AM) technology is growing up as a technology. Although up today slower and less reliable than traditional production methods, AM systems are showing to be very successful when producing parts with unconventional topologies or in small quantities. In addition, it is showing its capability to produce components with chemical compositions which should not be realized with standard production processes. In this paper some examples are reported of magnetic materials specifically designed for AM. In this work, powder of FeSi electric steel, with 6.5 wt.% Si content is considered to produce samples by AM. Aim of this paper is to investigate the microstructural and texture evolution of FeSi steels, with 6.5% Si, following annealing heat treatment, with the aim of identifying the conditions under which it could be possible to obtain the best magnetization behavior of the alloys.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43865164","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}
P. Ikubanni, M. Oki, A. A. Adeleke, E. Ajisegiri, M. Fajobi
The potentiodynamic polarization of aluminium 6063 alloy reinforced with silicon carbide (SiC) and palm kernel shell ash (PKSA) particulates at various mixing ratios were investigated. Double stir casting method was adopted for the production of the hybrid reinforced composites. The existence of the reinforcements within the matrix alloy acted as active sites for corrosion initiation. Hence, pitting corrosion was observed. The range of values for Ecorr and Icorr obtained at 24 h in 1.0 M H2SO4 were between -627.74 and -644.46 mV, and between 423.81 and 860.23 µA/cm2, respectively. The Ecorr values ranged from -654 to -697.22 mV, and the Icorr ranged from 1075.65 to 3057.16 µA/cm2 at 72 h in 1.0 M H2SO4. The relative resistance to corrosion of the samples is dependent on the thin oxide film formed on the surface of the samples.
研究了碳化硅(SiC)和棕榈仁壳灰(PKSA)颗粒增强6063铝合金在不同混合比下的动电位极化。采用双搅拌铸造法生产混杂增强复合材料。基体合金中增强体的存在充当了腐蚀引发的活性位点。因此,观察到点蚀。在1.0 M H2SO4中24小时获得的Ecorr和Icorr的值范围分别在-627.74和-644.46 mV之间和423.81和860.23µA/cm2之间。在1.0 M H2SO4中72小时时,Ecorr值范围为-654至-697.22 mV,Icorr范围为1075.65至3057.16µA/cm2。样品的相对耐腐蚀性取决于在样品表面形成的薄氧化膜。
{"title":"CORROSION BEHAVIOR OF Al/SiC/PKSA HYBRID COMPOSITES IN 1.0 M H2SO4 ENVIRONMENT USING POTENTIODYNAMIC POLARIZATION TECHNIQUE","authors":"P. Ikubanni, M. Oki, A. A. Adeleke, E. Ajisegiri, M. Fajobi","doi":"10.36547/ams.28.4.1561","DOIUrl":"https://doi.org/10.36547/ams.28.4.1561","url":null,"abstract":"The potentiodynamic polarization of aluminium 6063 alloy reinforced with silicon carbide (SiC) and palm kernel shell ash (PKSA) particulates at various mixing ratios were investigated. Double stir casting method was adopted for the production of the hybrid reinforced composites. The existence of the reinforcements within the matrix alloy acted as active sites for corrosion initiation. Hence, pitting corrosion was observed. The range of values for Ecorr and Icorr obtained at 24 h in 1.0 M H2SO4 were between -627.74 and -644.46 mV, and between 423.81 and 860.23 µA/cm2, respectively. The Ecorr values ranged from -654 to -697.22 mV, and the Icorr ranged from 1075.65 to 3057.16 µA/cm2 at 72 h in 1.0 M H2SO4. The relative resistance to corrosion of the samples is dependent on the thin oxide film formed on the surface of the samples.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47725950","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}
This paper investigated change of the mechanical properties of the superheater pipe steel grade P22 (ASTM A335) under constant stress of 9.68 MPa and various temperatures of 500-700 oC. The steel specimens were prepared from the new steel pipe taken from a coal-fired power plant in Vietnam, then heated to the given temperature and held for the predetermined time as 24, 48 and 72 hours in the atmosphere. The results showed that the mechanical properties of the steel P22 decreased with the increased temperature and time. This deterioration of the steel strength was caused by the redistribution of the carbide in the steel subjected under the elevated temperature and the constant stress. Although change in the microstructure including phase and grain size was not observed, the SEM micrographs showed that the carbide of the heated steel accumulated on the grain boundaries and the triple regions when the temperature and holding time increased. This phenomenon was attributed to reduce number of the carbide in the steel, resulting in decrease of the mechanical properties. The obtained results indicated that decrease of the mechanical properties of the steel pipe P22 can occur in the early period of working time in the practice.
{"title":"DECREASING MECHANICAL PROPERTIES OF THE SUPERHEATER STEEL GRADE P22 HEATED AT ELEVATED TEMPERATURE UNDER CONSTANT STRESS","authors":"A. Bui, C. Nguyen, ThuHien Nguyen","doi":"10.36547/ams.28.4.1610","DOIUrl":"https://doi.org/10.36547/ams.28.4.1610","url":null,"abstract":"This paper investigated change of the mechanical properties of the superheater pipe steel grade P22 (ASTM A335) under constant stress of 9.68 MPa and various temperatures of 500-700 oC. The steel specimens were prepared from the new steel pipe taken from a coal-fired power plant in Vietnam, then heated to the given temperature and held for the predetermined time as 24, 48 and 72 hours in the atmosphere. The results showed that the mechanical properties of the steel P22 decreased with the increased temperature and time. This deterioration of the steel strength was caused by the redistribution of the carbide in the steel subjected under the elevated temperature and the constant stress. Although change in the microstructure including phase and grain size was not observed, the SEM micrographs showed that the carbide of the heated steel accumulated on the grain boundaries and the triple regions when the temperature and holding time increased. This phenomenon was attributed to reduce number of the carbide in the steel, resulting in decrease of the mechanical properties. The obtained results indicated that decrease of the mechanical properties of the steel pipe P22 can occur in the early period of working time in the practice.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44164005","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}
G. Stornelli, Matteo Gaggiotti, D. Gattia, R. Schmidt, Mirko Sgambetterra, Anastasiya Tselikova, G. Zucca, A. Schino
The inter-critical heat affected zone (ICHAZ) appears to be one of the most brittle sections in the welding of high-strength micro-alloy steels (HSLA). Following multiple heating cycles in the temperature range between Ac1 and Ac3, the ICHAZ undergoes a strong loss of toughness and fatigue resistance, mainly caused by the formation of martensite-austenite constituent (MA). The presence of micro-alloying elements in HSLA steels induces variations in the formation of some microstructural constituents, more or less beneficial, which allow to improve the mechanical performance of a welded joint. The behavior in the inter-critical region of a S355 grade steel with 0.1wt% V addition is reported in this paper. Five double-pass welding thermal cycles were simulated using a dilatometer, with the maximum temperature of the secondary peak in the inter-critical area, in the range between 720 ° C and 790 ° C. The residual austenite dependence on inter-critical temperature is analyzed and related to the hardness behavior.
{"title":"VANADIUM ALLOYING IN S355 STRUCTURAL STEEL: EFFECT ON RESIDUAL AUSTENITE FORMATION IN WELDED JOINTS HEAT AFFECTED ZONE","authors":"G. Stornelli, Matteo Gaggiotti, D. Gattia, R. Schmidt, Mirko Sgambetterra, Anastasiya Tselikova, G. Zucca, A. Schino","doi":"10.36547/ams.28.3.1535","DOIUrl":"https://doi.org/10.36547/ams.28.3.1535","url":null,"abstract":"The inter-critical heat affected zone (ICHAZ) appears to be one of the most brittle sections in the welding of high-strength micro-alloy steels (HSLA). Following multiple heating cycles in the temperature range between Ac1 and Ac3, the ICHAZ undergoes a strong loss of toughness and fatigue resistance, mainly caused by the formation of martensite-austenite constituent (MA). The presence of micro-alloying elements in HSLA steels induces variations in the formation of some microstructural constituents, more or less beneficial, which allow to improve the mechanical performance of a welded joint. The behavior in the inter-critical region of a S355 grade steel with 0.1wt% V addition is reported in this paper. Five double-pass welding thermal cycles were simulated using a dilatometer, with the maximum temperature of the secondary peak in the inter-critical area, in the range between 720 ° C and 790 ° C. The residual austenite dependence on inter-critical temperature is analyzed and related to the hardness behavior.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46574555","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}
In this work, the evolution of MC-type Nb-rich primary carbides in a 35Ni-25Cr-Nb-type refractory alloy, commonly known as HP40-Nb, and its transformation into Ni-Nb silicide known as G-phase (Ni16Nb6Si7), has been studied. For this purpose, the experimental technique of scanning electron microscopy was used together with X-ray microanalysis to detect changes in the chemical composition of niobium carbide over time and at a given aging temperature. The microstructure of the studied alloy, in its as-cast condition, consists of an austenitic matrix strengthened by a network of primary eutectic-like carbides rich in chromium and niobium of the M23C6 and MC types, respectively. During aging of the alloy at high temperatures, microstructural changes take place such as the secondary precipitation of M23C6 type carbides and the transformation of the primary Nb-rich carbide towards the Ni-Nb-rich silicide. It has been found that the transformation begins at the interface of the niobium carbides with the matrix, progressing towards their interior with the development of aging.
{"title":"NbC TRANSFORMATION DURING AGING IN HP40-Nb HEAT RESISTANT ALLOY","authors":"M. H. Sosa Lissarrague, C. Lanz","doi":"10.36547/ams.28.3.1562","DOIUrl":"https://doi.org/10.36547/ams.28.3.1562","url":null,"abstract":"In this work, the evolution of MC-type Nb-rich primary carbides in a 35Ni-25Cr-Nb-type refractory alloy, commonly known as HP40-Nb, and its transformation into Ni-Nb silicide known as G-phase (Ni16Nb6Si7), has been studied. For this purpose, the experimental technique of scanning electron microscopy was used together with X-ray microanalysis to detect changes in the chemical composition of niobium carbide over time and at a given aging temperature. The microstructure of the studied alloy, in its as-cast condition, consists of an austenitic matrix strengthened by a network of primary eutectic-like carbides rich in chromium and niobium of the M23C6 and MC types, respectively. During aging of the alloy at high temperatures, microstructural changes take place such as the secondary precipitation of M23C6 type carbides and the transformation of the primary Nb-rich carbide towards the Ni-Nb-rich silicide. It has been found that the transformation begins at the interface of the niobium carbides with the matrix, progressing towards their interior with the development of aging.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46268425","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}
The present work deals with analysis of mechanical performance and microstructural appearance of quenched and tempered SS-304 welded joints made by MIG welding technique. Since welding involves a critical solidification and thereby lots of internal stresses. Hence, heat treatment becomes important for removing stresses. In the present work, two SS-304 welded plates were heat treated. First plate was in quenched condition, and another was in tempered state. In both the plates, mechanical properties like tensile strength, impact strength, and hardness were analyzed. In addition, the microstructural attributes of base metal, heat affected zone and welded joints in both the welded plates were analyzed through optical microscope. The fractography analysis was also carried out in this study to get information about failure characteristics of samples after tensile testing. A significant change in mechanical properties, such as, 150% improvement in toughness, 7% reduction in weld-zone hardness, 3% improvement in yield strength and 6% reduction in ultimate tensile strength was obtained after tempering work. Also, the tempering process had reformed the grain structure by creating twins in base metal, and lathy δ ferrite & γ+δ lamella in HAZ. The martensite formed in quenched specimen had been completely recovered into fine γ+δ matrix.
{"title":"ANALYSING EFFECT OF QUENCHING AND TEMPERING INTO MECHANICAL PROPERTIES AND MICROSTRUCTURE OF 304-SS WELDED PLATES","authors":"Saurabh Dewangan, S. Chattopadhyaya","doi":"10.36547/ams.28.3.1556","DOIUrl":"https://doi.org/10.36547/ams.28.3.1556","url":null,"abstract":"The present work deals with analysis of mechanical performance and microstructural appearance of quenched and tempered SS-304 welded joints made by MIG welding technique. Since welding involves a critical solidification and thereby lots of internal stresses. Hence, heat treatment becomes important for removing stresses. In the present work, two SS-304 welded plates were heat treated. First plate was in quenched condition, and another was in tempered state. In both the plates, mechanical properties like tensile strength, impact strength, and hardness were analyzed. In addition, the microstructural attributes of base metal, heat affected zone and welded joints in both the welded plates were analyzed through optical microscope. The fractography analysis was also carried out in this study to get information about failure characteristics of samples after tensile testing. A significant change in mechanical properties, such as, 150% improvement in toughness, 7% reduction in weld-zone hardness, 3% improvement in yield strength and 6% reduction in ultimate tensile strength was obtained after tempering work. Also, the tempering process had reformed the grain structure by creating twins in base metal, and lathy δ ferrite & γ+δ lamella in HAZ. The martensite formed in quenched specimen had been completely recovered into fine γ+δ matrix. ","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42933930","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}
The paper shows the results of a study of the influence of the cut-off method of the slag by using destructible plugs on the quantitative indicators of the redistribution of slag and metal in the steel ladle during the metal tapping operation from the converter. The laboratory setup simulates a real 160-ton industrial top-blown oxygen converter, and a steel ladle at a scale of 1:18 has been used to fulfill the study. Water was chosen as a liquid steel imitator, and machine oil was chosen for slag with parameters that ensure the similarity of physical parameters in the metal-slag system. The physical modelling of the tapping process of a two-phase converter bath in the case of a destructible plug in the tap hole compared to the tapping option without it showed a significant positive effect of the presence of the plug in the initial period from the moment the converter is tilted.
{"title":"STUDY ON A TWO-PHASE LOW-TEMPERATURE MODEL OF THE FEATURES OF METAL TAPPING IN BASIC OXYGEN FURNACE","authors":"T. Golub, L. Molchanov, A. Koveria, L. Kieush","doi":"10.36547/ams.28.3.1566","DOIUrl":"https://doi.org/10.36547/ams.28.3.1566","url":null,"abstract":"The paper shows the results of a study of the influence of the cut-off method of the slag by using destructible plugs on the quantitative indicators of the redistribution of slag and metal in the steel ladle during the metal tapping operation from the converter. The laboratory setup simulates a real 160-ton industrial top-blown oxygen converter, and a steel ladle at a scale of 1:18 has been used to fulfill the study. Water was chosen as a liquid steel imitator, and machine oil was chosen for slag with parameters that ensure the similarity of physical parameters in the metal-slag system. The physical modelling of the tapping process of a two-phase converter bath in the case of a destructible plug in the tap hole compared to the tapping option without it showed a significant positive effect of the presence of the plug in the initial period from the moment the converter is tilted.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69624969","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}
This work is devoted to the thermal stability and thermal expansion of dual-phase AlFeCoNiCu as-cast high-entropy alloy of equiatomic composition. The mix FCC + BCC phases is in AlFeCoNiCu high entropy alloy. According to characterized by EDS-analysis, Fe and Co are almost uniformly distributed in both phases in comparison with other elements. The BCC phase is rich in Ni and Al, and the FCC phase is Cu. Our measurement results of hardness and elastic modulus values for inter dendrites (FCC phase) and dendrites (BCC phase) of as-cast AlFeCoNiCu alloy showed the difference between there. Hardness values for inter dendrites and dendrites: 3.4±0.4GPa and 4.1±0.6GPa. Elastic modulus values for inter dendrites and dendrites: 130.5±2.0GPa and 166.5±5.6GPa. The thermal stability of the phases presented in AlFeCoNiCu as-cast high-entropy alloy has been studied with dilatometry and differential scanning calorimetry (DSC). The DSC thermogram shows an endothermic peak at 1000K. The coefficient of thermal expansion (CTE) curve shows linear increment from room temperature up to 1370K from (10.6 ± 0.3)×10-6K−1 to (27.7 ± 0.3) ×10-6K−1. The CTE temperature curve also shows the peak at 1000K. The peaks in the CTE temperature and the DSC curve suggest a phase transformation with increasing temperature up to~1000K.
{"title":"THERMAL STABILITY AND THERMAL EXPANSION BEHAVIOR OF AlFeCoNiCu AS-CAST HIGH-ENTROPY DUAL-PHASE ALLOY","authors":"K. Shmakova, V. Tsepelev, O. Chikova","doi":"10.36547/ams.28.3.1551","DOIUrl":"https://doi.org/10.36547/ams.28.3.1551","url":null,"abstract":"This work is devoted to the thermal stability and thermal expansion of dual-phase AlFeCoNiCu as-cast high-entropy alloy of equiatomic composition. The mix FCC + BCC phases is in AlFeCoNiCu high entropy alloy. According to characterized by EDS-analysis, Fe and Co are almost uniformly distributed in both phases in comparison with other elements. The BCC phase is rich in Ni and Al, and the FCC phase is Cu. Our measurement results of hardness and elastic modulus values for inter dendrites (FCC phase) and dendrites (BCC phase) of as-cast AlFeCoNiCu alloy showed the difference between there. Hardness values for inter dendrites and dendrites: 3.4±0.4GPa and 4.1±0.6GPa. Elastic modulus values for inter dendrites and dendrites: 130.5±2.0GPa and 166.5±5.6GPa. The thermal stability of the phases presented in AlFeCoNiCu as-cast high-entropy alloy has been studied with dilatometry and differential scanning calorimetry (DSC). The DSC thermogram shows an endothermic peak at 1000K. The coefficient of thermal expansion (CTE) curve shows linear increment from room temperature up to 1370K from (10.6 ± 0.3)×10-6K−1 to (27.7 ± 0.3) ×10-6K−1. The CTE temperature curve also shows the peak at 1000K. The peaks in the CTE temperature and the DSC curve suggest a phase transformation with increasing temperature up to~1000K.","PeriodicalId":44511,"journal":{"name":"Acta Metallurgica Slovaca","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42645811","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}