Pub Date : 2020-01-01DOI: 10.37904/metal.2020.3507
I. Šípová, D. Bartonek, V. Vodárek
The T24 steel grade has been frequently used for the construction of membrane walls in modern power plant boilers. This steel grade has been developed with the intention of welding without post weld heat treatment. However, commissioning of new units of power plants into service revealed many defects in homogeneous T24 welds. Several remedial measures have been proposed. One of them represents annealing of boilers before putting them into service at 450 °C. This paper deals with characterization of microhardness and microstructure of homogeneous peripheral butt T24 welds after annealing at 450 °C for 48 hours and subsequent annealing at 530 °C for 10 hours. The results revealed that annealing at 450 °C led to a further increase of hardness in overheated parts of heat affected zones of homogeneous T24 welds. Subsequent short-term annealing at temperature of 530 °C, which corresponded to the typical temperature of boilers commissioning, caused a significant effect of secondary hardening in overheated parts of heat affected zones of homogeneous T24 welds. TEM investigations were carried out in order to explain this effect.
{"title":"SECONDARY HARDENING OF HOMOGENEOUS T24 WELDS AFTER SHORT-TERM ANNEALING AT 450 and 530 °C","authors":"I. Šípová, D. Bartonek, V. Vodárek","doi":"10.37904/metal.2020.3507","DOIUrl":"https://doi.org/10.37904/metal.2020.3507","url":null,"abstract":"The T24 steel grade has been frequently used for the construction of membrane walls in modern power plant boilers. This steel grade has been developed with the intention of welding without post weld heat treatment. However, commissioning of new units of power plants into service revealed many defects in homogeneous T24 welds. Several remedial measures have been proposed. One of them represents annealing of boilers before putting them into service at 450 °C. This paper deals with characterization of microhardness and microstructure of homogeneous peripheral butt T24 welds after annealing at 450 °C for 48 hours and subsequent annealing at 530 °C for 10 hours. The results revealed that annealing at 450 °C led to a further increase of hardness in overheated parts of heat affected zones of homogeneous T24 welds. Subsequent short-term annealing at temperature of 530 °C, which corresponded to the typical temperature of boilers commissioning, caused a significant effect of secondary hardening in overheated parts of heat affected zones of homogeneous T24 welds. TEM investigations were carried out in order to explain this effect.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77289654","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 : 2020-01-01DOI: 10.37904/metal.2020.3572
J. Antoš, K. Lencová, P. Šulcová, A. Keslová, J. Duliškovič
Atmospheric plasma sprayed (APS) chromia coating provides excellent wear behaviour combined with corrosion resistance even in aggressive environments. In this paper, the influence of variable spraying parameters on the mechanical properties and microstructure of chromia coatings is investigated. Main goal for this optimization is to achieve high wear and abrasive resistance. APS ceramic coatings such as chromia could perform in some industrial applications as well as more commonly used HVOF (high velocity oxygen fuel) cermet coatings, especially in wear and abrasion resistance. In order to be able to compete with hard and wear resistant cermet HVOF coatings, optimization of spraying parameters for this particular chromia powder is required. High throughput cascaded plasma troch is used for the spraying process. Set of five different spraying parameters is used varying only primary plasma gas flow rate and input electrical current with rest of spraying parameters set constant, including carrier gas flow. Critical plasma spraying parameter or CPSP is also utilized in the design stage of experiment. Coatings sprayed on low carbon steel substrate underwent superficial Rockwell indentation, optical microscopy on polished cross section, adhesion strength testing and dry sand abrasion test. No significant correlation between CPSP values and hardness, adhesive strength or abrasion resistance was observed. High input electrical current combined with rather high plasma gas flow provided better abrasion resistance than lower input electrical current and flow rates. Coating performing best in abrasion test also displayed by far the highest adhesive strength to substrate material, so presumably having also the highest cohesion strength between splats may lead to less inter splat decohesion or chipping during dry sand abrasion.
{"title":"spraying parameters optimization for wear and abrasion resistance of Cr2O3 coating deposited with cascaded plasma torch","authors":"J. Antoš, K. Lencová, P. Šulcová, A. Keslová, J. Duliškovič","doi":"10.37904/metal.2020.3572","DOIUrl":"https://doi.org/10.37904/metal.2020.3572","url":null,"abstract":"Atmospheric plasma sprayed (APS) chromia coating provides excellent wear behaviour combined with corrosion resistance even in aggressive environments. In this paper, the influence of variable spraying parameters on the mechanical properties and microstructure of chromia coatings is investigated. Main goal for this optimization is to achieve high wear and abrasive resistance. APS ceramic coatings such as chromia could perform in some industrial applications as well as more commonly used HVOF (high velocity oxygen fuel) cermet coatings, especially in wear and abrasion resistance. In order to be able to compete with hard and wear resistant cermet HVOF coatings, optimization of spraying parameters for this particular chromia powder is required. High throughput cascaded plasma troch is used for the spraying process. Set of five different spraying parameters is used varying only primary plasma gas flow rate and input electrical current with rest of spraying parameters set constant, including carrier gas flow. Critical plasma spraying parameter or CPSP is also utilized in the design stage of experiment. Coatings sprayed on low carbon steel substrate underwent superficial Rockwell indentation, optical microscopy on polished cross section, adhesion strength testing and dry sand abrasion test. No significant correlation between CPSP values and hardness, adhesive strength or abrasion resistance was observed. High input electrical current combined with rather high plasma gas flow provided better abrasion resistance than lower input electrical current and flow rates. Coating performing best in abrasion test also displayed by far the highest adhesive strength to substrate material, so presumably having also the highest cohesion strength between splats may lead to less inter splat decohesion or chipping during dry sand abrasion.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85938828","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 : 2020-01-01DOI: 10.37904/metal.2020.3440
Š. Langová, D. Matýsek
Steelmaking dust and sludge are hazardous waste materials containing leachable compounds of zinc, lead, cadmium, and other environmentally harmful elements. In this study, acetic and butyric acid were used as leaching reagents to remove easily soluble zincite selectively. The effect of the acid concentration, liquid/solid ratio, temperature and time on the metal extraction and selectivity were studied. The results for the acetic and butyric are similar. Zincite can be selectively removed using diluted acids. Most of calcium was also leached. Zinc ferrite remained in the solid residuum. The selectivity decreases with the increasing time, temperature and acid concentration. The leach liquor can be used for the preparation of nanomaterials for photocatalysis. The solid residue will be studied using the electrochemical methods and thermal analysis with the view of finding some application.
{"title":"Leaching of steel-making wastes in organic acids","authors":"Š. Langová, D. Matýsek","doi":"10.37904/metal.2020.3440","DOIUrl":"https://doi.org/10.37904/metal.2020.3440","url":null,"abstract":"Steelmaking dust and sludge are hazardous waste materials containing leachable compounds of zinc, lead, cadmium, and other environmentally harmful elements. In this study, acetic and butyric acid were used as leaching reagents to remove easily soluble zincite selectively. The effect of the acid concentration, liquid/solid ratio, temperature and time on the metal extraction and selectivity were studied. The results for the acetic and butyric are similar. Zincite can be selectively removed using diluted acids. Most of calcium was also leached. Zinc ferrite remained in the solid residuum. The selectivity decreases with the increasing time, temperature and acid concentration. The leach liquor can be used for the preparation of nanomaterials for photocatalysis. The solid residue will be studied using the electrochemical methods and thermal analysis with the view of finding some application.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85777316","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 : 2020-01-01DOI: 10.37904/metal.2020.3532
S. Jezek, J. Horváth, L. Kolařík, J. Janovec, M. Kolaříková
The experiment aimed on influence of shielding gas flow rate on properties of single V groove butt weld of high strength ultra-fine grained steel S960QL (XABO 960) and filler material G 89 6 M21 Mn4Ni2CrMo (X90) is described in this article. The steel S960QL is sensitive to presence of hydrogen in material structure, in exceed of maximal recommended content (<5ml/100g) the cold cracking may take place. During the experiment specimen 1 with reduced flow rate 5l.min-1 and specimen 2 with recommended flow rate 14l.min-1 was welded. The active shielding gas Corgon with the 82% Ar and 18% CO2 ratio was used. Flow rate of shielding gas has a noticeable influence on properties of welded joint. Because of specimen 1 reduced flow rate the full penetration was not achieved, chemical composition evaluation of weld metal shows fewer deoxidizing elements (Si, Mn, Ti) and increased hydrogen contents (≈18 ml/100g) as a result of chemical reaction between weld metal and air during welding. The increased hydrogen content, type of base metal and lack of penetration were the reasons of fracture of the specimen 1. Cold cracking was confirmed by hydrogen content measurement and by fracture surface evaluation by optical and electron microscopy. The porosity, fish eyes and cleavage facets typical for brittle fracture was found by microscopy. The high-quality weld with low content of hydrogen can be obtained with the recommended shielding gas flow rate, the flow rate adjustment is one of method how to avoid cold cracking of welds.
{"title":"Influence of shielding gas flow rate on properties of steel S960QL welded joint","authors":"S. Jezek, J. Horváth, L. Kolařík, J. Janovec, M. Kolaříková","doi":"10.37904/metal.2020.3532","DOIUrl":"https://doi.org/10.37904/metal.2020.3532","url":null,"abstract":"The experiment aimed on influence of shielding gas flow rate on properties of single V groove butt weld of high strength ultra-fine grained steel S960QL (XABO 960) and filler material G 89 6 M21 Mn4Ni2CrMo (X90) is described in this article. The steel S960QL is sensitive to presence of hydrogen in material structure, in exceed of maximal recommended content (<5ml/100g) the cold cracking may take place. During the experiment specimen 1 with reduced flow rate 5l.min-1 and specimen 2 with recommended flow rate 14l.min-1 was welded. The active shielding gas Corgon with the 82% Ar and 18% CO2 ratio was used. Flow rate of shielding gas has a noticeable influence on properties of welded joint. Because of specimen 1 reduced flow rate the full penetration was not achieved, chemical composition evaluation of weld metal shows fewer deoxidizing elements (Si, Mn, Ti) and increased hydrogen contents (≈18 ml/100g) as a result of chemical reaction between weld metal and air during welding. The increased hydrogen content, type of base metal and lack of penetration were the reasons of fracture of the specimen 1. Cold cracking was confirmed by hydrogen content measurement and by fracture surface evaluation by optical and electron microscopy. The porosity, fish eyes and cleavage facets typical for brittle fracture was found by microscopy. The high-quality weld with low content of hydrogen can be obtained with the recommended shielding gas flow rate, the flow rate adjustment is one of method how to avoid cold cracking of welds.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"161 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86180007","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 : 2020-01-01DOI: 10.37904/metal.2020.3588
M. Kalenga, D. Nyembwe, M. Tangstad
During the production of high carbon ferromanganese, the feed undergoes different stages of reduction. Three main zones were assumed instead of traditional four. The influence of phases formed during pre-reduction have a gigantic impact on the kinetics of the quality of the final products. In the current investigation, basic South African manganese ores were used. Two different fluxes were tested namely alumina and silica. For the experiments the ore, flux and coke were mixed and milled to 75 µm for 15 minutes for better homogenization. Using a graphite crucible placed into a silica crucible, the crucible was placed in the hot zone of the alumina tube furnace which was programmed at different temperatures. To avoid the reaction between the graphite crucible and the manganese ore. Argon was blown into the furnace from room temperature to 600 °C then switched off to allow carbon only to react with the oxide ore. The furnace was kept for two hours and switched off until the furnace reached 600 °C then argon was blown into the furnace down to room temperature. XRD, XRF and SEM were used for characterization. With the use of alumina as fluxing agent the temperatures used were 1200, 1250 and 1300 °C whereas with silica used as fluxing the temperatures tested were 1200 and 1350 °C. The influence of the A/S (alumina/silica) ratio on the kinetics was assessed.
{"title":"study on the influence of Al2O3/SiO2 on the KINETICS in the prereduction zone during high carbon ferromanganese production using basic south african manganese ores","authors":"M. Kalenga, D. Nyembwe, M. Tangstad","doi":"10.37904/metal.2020.3588","DOIUrl":"https://doi.org/10.37904/metal.2020.3588","url":null,"abstract":"During the production of high carbon ferromanganese, the feed undergoes different stages of reduction. Three main zones were assumed instead of traditional four. The influence of phases formed during pre-reduction have a gigantic impact on the kinetics of the quality of the final products. In the current investigation, basic South African manganese ores were used. Two different fluxes were tested namely alumina and silica. For the experiments the ore, flux and coke were mixed and milled to 75 µm for 15 minutes for better homogenization. Using a graphite crucible placed into a silica crucible, the crucible was placed in the hot zone of the alumina tube furnace which was programmed at different temperatures. To avoid the reaction between the graphite crucible and the manganese ore. Argon was blown into the furnace from room temperature to 600 °C then switched off to allow carbon only to react with the oxide ore. The furnace was kept for two hours and switched off until the furnace reached 600 °C then argon was blown into the furnace down to room temperature. XRD, XRF and SEM were used for characterization. With the use of alumina as fluxing agent the temperatures used were 1200, 1250 and 1300 °C whereas with silica used as fluxing the temperatures tested were 1200 and 1350 °C. The influence of the A/S (alumina/silica) ratio on the kinetics was assessed.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90234682","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 : 2020-01-01DOI: 10.37904/metal.2020.3648
M. Krynke
This article addresses the problem of supply chain management in the foundry industry. In the case of manufacturing companies assisting in the production process by external entities, it is important to consider cooperation starting from the settlement of raw materials or semi-finished products to the acceptance of production from a subcontractor along with the registration of the costs of service, transport and storage. Subcontractor's production plans should be included in the operational production schedule. The article solves a specific problem regarding cooperation with suppliers of alloying elements for the production of cast iron. A cast production, transport and storage plan has been developed so that the total costs of production, transport and storage are as low as possible. A mathematical model was formulated for this problem. An algorithm is presented to solve the problem of supplier selection. The proposed analysis is the starting point for an efficient business planning process, where it is required to transform information from various areas (sales, marketing and business partners) into a common set of planning data and indicators.
{"title":"Application of linear programming in supply chain management in the foundry","authors":"M. Krynke","doi":"10.37904/metal.2020.3648","DOIUrl":"https://doi.org/10.37904/metal.2020.3648","url":null,"abstract":"This article addresses the problem of supply chain management in the foundry industry. In the case of manufacturing companies assisting in the production process by external entities, it is important to consider cooperation starting from the settlement of raw materials or semi-finished products to the acceptance of production from a subcontractor along with the registration of the costs of service, transport and storage. Subcontractor's production plans should be included in the operational production schedule. The article solves a specific problem regarding cooperation with suppliers of alloying elements for the production of cast iron. A cast production, transport and storage plan has been developed so that the total costs of production, transport and storage are as low as possible. A mathematical model was formulated for this problem. An algorithm is presented to solve the problem of supplier selection. The proposed analysis is the starting point for an efficient business planning process, where it is required to transform information from various areas (sales, marketing and business partners) into a common set of planning data and indicators.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83811718","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 : 2020-01-01DOI: 10.37904/metal.2020.3503
Lukáš Kudrna, P. Váňová, J. Malcharcziková, T. Kubín
This article is about the chemical composition and microstructure of the outer door handles of the TATRA 87. The TATRA 87 was produced between 1937 and 1950. It was a timeless car with an aerodynamic self-supporting body and an eight-cylinder engine mounted at the rear. The material analysis was carried out on four pieces of historical outer door handles of different ages and conditions. These were door handle lent by the ECORRA s. r. o. company. The chemical composition of all four door handles was detected with an X-ray spectrometer using the ED-XRF method, which could be performed without significant damage to these historical pieces. In addition, other methods were used for two samples of door handles, namely the glow discharge optical emission spectrometry (GDOES) and metallographic analysis, which were, however, associated with destructive preparation of samples. It was found that four of the door handles samples used for the same type of car had different finishes. Although more modern chrome plating has been used in the Tatra since the early 1930, surprisingly, nickel was used for surface treatment here. There could have been more reasons why this was the case. Most likely, the shutdown of a part of the operation, or the lack of supply in the time of The Second World War, could have caused this phenomenon. The results of the measurements will be used in the production of accurate copies of outer door handles, which are no longer available in the vintage cars market today.
{"title":"MATERIAL ANALYSIS OF OUTER DOOR HANDLES OF THE HISTORICAL CAR TATRA 87","authors":"Lukáš Kudrna, P. Váňová, J. Malcharcziková, T. Kubín","doi":"10.37904/metal.2020.3503","DOIUrl":"https://doi.org/10.37904/metal.2020.3503","url":null,"abstract":"This article is about the chemical composition and microstructure of the outer door handles of the TATRA 87. The TATRA 87 was produced between 1937 and 1950. It was a timeless car with an aerodynamic self-supporting body and an eight-cylinder engine mounted at the rear. The material analysis was carried out on four pieces of historical outer door handles of different ages and conditions. These were door handle lent by the ECORRA s. r. o. company. The chemical composition of all four door handles was detected with an X-ray spectrometer using the ED-XRF method, which could be performed without significant damage to these historical pieces. In addition, other methods were used for two samples of door handles, namely the glow discharge optical emission spectrometry (GDOES) and metallographic analysis, which were, however, associated with destructive preparation of samples. It was found that four of the door handles samples used for the same type of car had different finishes. Although more modern chrome plating has been used in the Tatra since the early 1930, surprisingly, nickel was used for surface treatment here. There could have been more reasons why this was the case. Most likely, the shutdown of a part of the operation, or the lack of supply in the time of The Second World War, could have caused this phenomenon. The results of the measurements will be used in the production of accurate copies of outer door handles, which are no longer available in the vintage cars market today.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90664422","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 : 2020-01-01DOI: 10.37904/metal.2020.3450
H. Ovčačíková, M. Velička, P. Maierová, J. Vlček, J. Halamová
Blast furnace slag is generated as a by-product of the metallurgical industry and can be called “multifunctional waste”. It can be used in the building industry, reused in production or landfilled. Recovery of waste brings both economical and ecological benefits. Granulated blast furnace slag (GBFS) has a variable chemical composition and belongs to the group of so-called latent hydraulic materials. Alkaline activation (AA) is followed by the formation of CSH phases, which are an effective product of chemical processes in the mixture. GBFS is commonly activated by a liquid activator. This experiment focused on alkaline activation of GBFS with the use of liquid (water glass) and with a solid alkaline activator (Na 2 SiO 3 ) with treatment silicate modulus Ms = 1. GBFS was characterized by X-ray powder diffraction (XRD), X-ray fluorescence spectroscopy (XRF), granulometry (PSD), thermogravimetric analysis (TG) and differential thermal analysis (DTA). The samples were evaluated in terms of their compressive strength and bulk density after 2, 7 and 28 days of hydration. Annealing loss and bulk density of original GBFS were determined at ∆100, ∆200 and ∆300°C.
{"title":"EXPERIMENTAL STUDIES OF GRANULATED BLAST FURNACE SLAG","authors":"H. Ovčačíková, M. Velička, P. Maierová, J. Vlček, J. Halamová","doi":"10.37904/metal.2020.3450","DOIUrl":"https://doi.org/10.37904/metal.2020.3450","url":null,"abstract":"Blast furnace slag is generated as a by-product of the metallurgical industry and can be called “multifunctional waste”. It can be used in the building industry, reused in production or landfilled. Recovery of waste brings both economical and ecological benefits. Granulated blast furnace slag (GBFS) has a variable chemical composition and belongs to the group of so-called latent hydraulic materials. Alkaline activation (AA) is followed by the formation of CSH phases, which are an effective product of chemical processes in the mixture. GBFS is commonly activated by a liquid activator. This experiment focused on alkaline activation of GBFS with the use of liquid (water glass) and with a solid alkaline activator (Na 2 SiO 3 ) with treatment silicate modulus Ms = 1. GBFS was characterized by X-ray powder diffraction (XRD), X-ray fluorescence spectroscopy (XRF), granulometry (PSD), thermogravimetric analysis (TG) and differential thermal analysis (DTA). The samples were evaluated in terms of their compressive strength and bulk density after 2, 7 and 28 days of hydration. Annealing loss and bulk density of original GBFS were determined at ∆100, ∆200 and ∆300°C.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"29 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77976569","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 : 2020-01-01DOI: 10.37904/metal.2020.3563
Vít Záliš, J. Bárta
The aim of this study is to compare the corrosion resistance of anodic oxidation coatings on Al2024 alloy. Due to its composition with a high content of alloying elements (mainly Cu), anodization of this alloy is one of the difficult ones compared to most other alloys or pure aluminium. In this study, the Cr6+ free baths were used for anodic oxidation of the Al 2024 alloy because of high toxicity of Cr6+ based baths, which are legislatively restricted nowadays. One of the possible ways is the use of mixtures of organic and inorganic acids and various additives (such as e.g. tartaric, citric, glycolic, malonic acid etc.). It is also possible to use commercial products as additives for sulfuric acid anodization (SAA). In this study, the samples were anodized in four types of anodizing baths and subsequently sealed in boiling water. The surface and metallographic specimen were observed by optical microscope and scanning electron microscope (SEM). The thickness was measured using the eddy current method. The anti-corrosion properties of the layers were verified using the accelerated Machu test.
{"title":"Comparison of different agents for surface treatment of aluminium by electrochemical oxidation","authors":"Vít Záliš, J. Bárta","doi":"10.37904/metal.2020.3563","DOIUrl":"https://doi.org/10.37904/metal.2020.3563","url":null,"abstract":"The aim of this study is to compare the corrosion resistance of anodic oxidation coatings on Al2024 alloy. Due to its composition with a high content of alloying elements (mainly Cu), anodization of this alloy is one of the difficult ones compared to most other alloys or pure aluminium. In this study, the Cr6+ free baths were used for anodic oxidation of the Al 2024 alloy because of high toxicity of Cr6+ based baths, which are legislatively restricted nowadays. One of the possible ways is the use of mixtures of organic and inorganic acids and various additives (such as e.g. tartaric, citric, glycolic, malonic acid etc.). It is also possible to use commercial products as additives for sulfuric acid anodization (SAA). In this study, the samples were anodized in four types of anodizing baths and subsequently sealed in boiling water. The surface and metallographic specimen were observed by optical microscope and scanning electron microscope (SEM). The thickness was measured using the eddy current method. The anti-corrosion properties of the layers were verified using the accelerated Machu test.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76303943","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 : 2020-01-01DOI: 10.37904/metal.2020.3472
L. Kander, M. Greger
The paper deals with comparison of forging technology and selected forming factors on structure of the tool steel EN X160CrMoV12-1. Steel under investigation is a high-alloyed Cr-Mo-V tool steel for exploitation both in hot and cold conditions. The steel is characterised by difficult formability and high resistance to deformation in the whole range of the forging temperatures. The authors compare the structure of forged rods with a diameter of 250 mm, forged products on the radial forging machines with second one forged on hydraulic press CKW 1600.
{"title":"STRUCTURE AND MECHANICAL PROPERTIES TOOL STEEL AFTER FORGING","authors":"L. Kander, M. Greger","doi":"10.37904/metal.2020.3472","DOIUrl":"https://doi.org/10.37904/metal.2020.3472","url":null,"abstract":"The paper deals with comparison of forging technology and selected forming factors on structure of the tool steel EN X160CrMoV12-1. Steel under investigation is a high-alloyed Cr-Mo-V tool steel for exploitation both in hot and cold conditions. The steel is characterised by difficult formability and high resistance to deformation in the whole range of the forging temperatures. The authors compare the structure of forged rods with a diameter of 250 mm, forged products on the radial forging machines with second one forged on hydraulic press CKW 1600.","PeriodicalId":18449,"journal":{"name":"METAL 2020 Conference Proeedings","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74828512","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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