It is important to clarify the effect of BaO in phosphorus partition of multiphase flux. In current work, the slag CaO-SiO2-FetO-P2O5 with different contents of BaO was cooled from 1873 K to 1673 K to investigate the effect of BaO on phosphorus partition of solid solution. The phosphorous partition between the solid solution phase and liquid phase was obtained. In order to further inspect the effect of BaO on phosphorus partition, the experiment of reaction between 2CaO · SiO2 (C2S)-FetO/Fe2O3-BaO slag and hot metal was carried out. Furthermore, the CaO-FetO slag was also studied to compare the dephosphorization effect to C2S-FetO/Fe2O3-BaO slag. The phosphorus partition ratios Lp between the slag and hot metal were obtained. The result showed that when the slag CaO-SiO2-FetO-P2O5-BaO with various BaO content was cooled down from 1873 K to 1673 K, the solid solution was precipitated, and the enrichment of phosphorus in solid solution phase was improved with the addition of BaO. The phosphorus element content in solid solution increased from 4.16% to 5.27% with the increasing of BaO content in slag from 0 to 15% at the interval of 5%. Based on the experiment of reaction between slag and hot metal, the phosphorus content in hot metal showed that the barium ion was more beneficial to enrichment of phosphorus and the function of BaO was promoted by the addition of Fe2O3. The phosphorus partition ratio Lp between the slag C2S-FetO-BaO and hot metal was 295.38, which was higher than 208.24 that without BaO. The phosphorus partition ratio Lp between the slag CaO-FetO and hot metal was 217.50. The phosphorus partition ratio Lp between the slag C2S-Fe2O3-BaO and hot metal was 418.75, higher than that of the slag C2S-FetO-BaO.
{"title":"Effect of multiphase flux with BaO addition on phosphorus partition","authors":"Yan Song, Xiaojun Hu, K. Chou","doi":"10.1051/metal/2022099","DOIUrl":"https://doi.org/10.1051/metal/2022099","url":null,"abstract":"It is important to clarify the effect of BaO in phosphorus partition of multiphase flux. In current work, the slag CaO-SiO2-FetO-P2O5 with different contents of BaO was cooled from 1873 K to 1673 K to investigate the effect of BaO on phosphorus partition of solid solution. The phosphorous partition between the solid solution phase and liquid phase was obtained. In order to further inspect the effect of BaO on phosphorus partition, the experiment of reaction between 2CaO · SiO2 (C2S)-FetO/Fe2O3-BaO slag and hot metal was carried out. Furthermore, the CaO-FetO slag was also studied to compare the dephosphorization effect to C2S-FetO/Fe2O3-BaO slag. The phosphorus partition ratios Lp between the slag and hot metal were obtained. The result showed that when the slag CaO-SiO2-FetO-P2O5-BaO with various BaO content was cooled down from 1873 K to 1673 K, the solid solution was precipitated, and the enrichment of phosphorus in solid solution phase was improved with the addition of BaO. The phosphorus element content in solid solution increased from 4.16% to 5.27% with the increasing of BaO content in slag from 0 to 15% at the interval of 5%. Based on the experiment of reaction between slag and hot metal, the phosphorus content in hot metal showed that the barium ion was more beneficial to enrichment of phosphorus and the function of BaO was promoted by the addition of Fe2O3. The phosphorus partition ratio Lp between the slag C2S-FetO-BaO and hot metal was 295.38, which was higher than 208.24 that without BaO. The phosphorus partition ratio Lp between the slag CaO-FetO and hot metal was 217.50. The phosphorus partition ratio Lp between the slag C2S-Fe2O3-BaO and hot metal was 418.75, higher than that of the slag C2S-FetO-BaO.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131580711","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}
Linchuan Wang, Yong-gang Wei, Shiwei Zhou, Bo Li, Hua Wang
The direct-to-blister smelting process realizes single furnace smelting from chalcocite to blister copper. This process saves the matte transport process, avoids multiple feeding in the smelting process, and has the advantages of high productivity, a short production process, and less SO2 pollution. By comparing with the phase diagram of iron silicate slag system, it shows that calcium ferrite slag system is more suitable for direct-to-blister smelting under the condition of high oxygen potential. In this study, high-grade copper concentrate was used as the raw material and direct-to-blister smelting experiments were carried out at the laboratory scale. The variation of copper recovery with CaO/Fe ratio, smelting temperature and sedimentation time was studied. The phase composition of slag and the loss of copper in slag were analyzed by X-ray diffraction (XRD) and scanning electron microscopy with an energy spectrometer (SEM-EDS). The results showed that by adjusting process parameters, the copper recovery can reach 90.15 wt.% and the blister copper grade is more than 98.50 wt.%. It provides a theoretical basis for the industrial application of calcium ferrite slag in direct-to-blister smelting.
{"title":"Direct-to-blister smelting of copper concentrate based on a calcium ferrite slag system","authors":"Linchuan Wang, Yong-gang Wei, Shiwei Zhou, Bo Li, Hua Wang","doi":"10.1051/metal/2023038","DOIUrl":"https://doi.org/10.1051/metal/2023038","url":null,"abstract":"The direct-to-blister smelting process realizes single furnace smelting from chalcocite to blister copper. This process saves the matte transport process, avoids multiple feeding in the smelting process, and has the advantages of high productivity, a short production process, and less SO2 pollution. By comparing with the phase diagram of iron silicate slag system, it shows that calcium ferrite slag system is more suitable for direct-to-blister smelting under the condition of high oxygen potential. In this study, high-grade copper concentrate was used as the raw material and direct-to-blister smelting experiments were carried out at the laboratory scale. The variation of copper recovery with CaO/Fe ratio, smelting temperature and sedimentation time was studied. The phase composition of slag and the loss of copper in slag were analyzed by X-ray diffraction (XRD) and scanning electron microscopy with an energy spectrometer (SEM-EDS). The results showed that by adjusting process parameters, the copper recovery can reach 90.15 wt.% and the blister copper grade is more than 98.50 wt.%. It provides a theoretical basis for the industrial application of calcium ferrite slag in direct-to-blister smelting.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132830199","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}
Gurunathan Saravanan, G. Bhaskar, U. Elaiyarasan, Raman Mookkan Alagu
Nowadays, usages of laminated composites have been extended to various applications such as automotive, aircraft and aerospace due to its high strength-weight ratio. Generally, aluminium alloys are developed using various casting techniques to achieve the required properties. However, laminated aluminium composites have received great attention among the scientist due to the weight reduction, the damping capacity they offer etc. In this present investigation, carbon and glass fibre laminated aluminium (Al2024-T3) composites are prepared by hand lay-up technique. Different form of aluminium structure namely sheet and mesh are used to fabricate − the composites. Different composites are prepared namely carbon fibre aluminium sheet laminate (CFASL), carbon fibre aluminium mesh laminate (CFAML), glass fibre aluminium sheet laminate (GFASL) and carbon fibre aluminium mesh laminate (GFAML). Effects of reinforcement of fibre on tensile, bending and flexural strength are studied. The microstructure of the composites is captured using scanning electron microscope (SEM) to study the failure mechanism. It was revealed that the CFASL and CFAML offered superior mechanical properties compared to the GFASL and GFAML. Higher tensile, bending and flexural strengths were obtained with carbon fibre and aluminium sheet laminated composites. They withstand the higher stresses due to less debonding and matrix cracking. Debonding and fibre breaking mechanisms observed in the glass fibre laminated composites caused reduced strength. CFASL composites showed superior mechanical properties followed by CFAML, GFASL and GFAML.
{"title":"A study on mechanical and microstructure behaviour of carbon and glass fibre reinforced Al 2024-T3 laminated composite","authors":"Gurunathan Saravanan, G. Bhaskar, U. Elaiyarasan, Raman Mookkan Alagu","doi":"10.1051/metal/2023001","DOIUrl":"https://doi.org/10.1051/metal/2023001","url":null,"abstract":"Nowadays, usages of laminated composites have been extended to various applications such as automotive, aircraft and aerospace due to its high strength-weight ratio. Generally, aluminium alloys are developed using various casting techniques to achieve the required properties. However, laminated aluminium composites have received great attention among the scientist due to the weight reduction, the damping capacity they offer etc. In this present investigation, carbon and glass fibre laminated aluminium (Al2024-T3) composites are prepared by hand lay-up technique. Different form of aluminium structure namely sheet and mesh are used to fabricate − the composites. Different composites are prepared namely carbon fibre aluminium sheet laminate (CFASL), carbon fibre aluminium mesh laminate (CFAML), glass fibre aluminium sheet laminate (GFASL) and carbon fibre aluminium mesh laminate (GFAML). Effects of reinforcement of fibre on tensile, bending and flexural strength are studied. The microstructure of the composites is captured using scanning electron microscope (SEM) to study the failure mechanism. It was revealed that the CFASL and CFAML offered superior mechanical properties compared to the GFASL and GFAML. Higher tensile, bending and flexural strengths were obtained with carbon fibre and aluminium sheet laminated composites. They withstand the higher stresses due to less debonding and matrix cracking. Debonding and fibre breaking mechanisms observed in the glass fibre laminated composites caused reduced strength. CFASL composites showed superior mechanical properties followed by CFAML, GFASL and GFAML.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131438451","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}
Ren-sheng Chu, Zhan-jun Li, A. Malfliet, B. Blanpain, M. Guo
In the present work, the formation and growth of Al-Ti-O complex inclusions in the steel after SiMn and Ti deoxidation is systematically investigated. The evolution with time of the size, composition and morphology of the Al-Ti-O complex inclusions were studied. After adding 70TiFe alloy, the inclusion composition changed from Si-Mn-Al to Ti-Al-O-N. The growth of the inclusions after a deoxidation time of 30 s is mainly controlled by turbulent collisions. The three-dimensional morphology and shape factor of the inclusions is determined to research the growth pattern of Al-Ti inclusions.
{"title":"Growth mechanism of Al-Ti-O inclusions in steelmaking process","authors":"Ren-sheng Chu, Zhan-jun Li, A. Malfliet, B. Blanpain, M. Guo","doi":"10.1051/metal/2022021","DOIUrl":"https://doi.org/10.1051/metal/2022021","url":null,"abstract":"In the present work, the formation and growth of Al-Ti-O complex inclusions in the steel after SiMn and Ti deoxidation is systematically investigated. The evolution with time of the size, composition and morphology of the Al-Ti-O complex inclusions were studied. After adding 70TiFe alloy, the inclusion composition changed from Si-Mn-Al to Ti-Al-O-N. The growth of the inclusions after a deoxidation time of 30 s is mainly controlled by turbulent collisions. The three-dimensional morphology and shape factor of the inclusions is determined to research the growth pattern of Al-Ti inclusions.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134641896","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, good bonding between the high-entropy alloy (HEA) CuCoCrFeNi and TC4 titanium alloy was obtained through vacuum diffusion welding at a joining temperature of 1000 °C for 60 min under a pressure of 5 MPa. The results showed that the typical interfacial microstructure of the CuCoCrFeNi/TC4 joint was TC4/diffusion layer/island structure/dendritic structure/diffusion layer/HEA. Compared with Ti atoms, atoms such as Cr and Co from the CuCoCrFeNi substrate were prone to diffuse into the other material. Intermetallic compounds Cu0.5Fe0.5Ti and Co0.15Ni0.85Ti, solid solutions Ti(Fe, Cr)ss and amorphous materials were produced in the joint. The self-diffusion activation energy formula [see formula in PDF] can be used to approximate the order of diffusion capacity of elements, which follows in Cr >Fe> Co > Ni.
在5mpa压力下，焊接温度为1000℃，焊接时间为60min，实现了高熵合金(HEA) CuCoCrFeNi与TC4钛合金的良好结合。结果表明:CuCoCrFeNi/TC4接头的典型界面组织为TC4/扩散层/岛状结构/枝晶结构/扩散层/HEA;与Ti原子相比，CuCoCrFeNi衬底中的Cr和Co等原子更容易扩散到其他材料中。接头中产生了Cu0.5Fe0.5Ti和Co0.15Ni0.85Ti金属间化合物、Ti(Fe, Cr)ss固溶体和非晶态材料。自扩散活化能公式[见PDF中的公式]可以用来近似元素的扩散能力的顺序，Cr >Fe> Co > Ni。
{"title":"Interfacial behaviour of the high-entropy alloy CuCoCrFeNi and TC4 joint obtained by vacuum diffusion welding","authors":"Xianju Zhang, Wuxing Ou, Weihao Deng","doi":"10.1051/metal/2022062","DOIUrl":"https://doi.org/10.1051/metal/2022062","url":null,"abstract":"In this work, good bonding between the high-entropy alloy (HEA) CuCoCrFeNi and TC4 titanium alloy was obtained through vacuum diffusion welding at a joining temperature of 1000 °C for 60 min under a pressure of 5 MPa. The results showed that the typical interfacial microstructure of the CuCoCrFeNi/TC4 joint was TC4/diffusion layer/island structure/dendritic structure/diffusion layer/HEA. Compared with Ti atoms, atoms such as Cr and Co from the CuCoCrFeNi substrate were prone to diffuse into the other material. Intermetallic compounds Cu0.5Fe0.5Ti and Co0.15Ni0.85Ti, solid solutions Ti(Fe, Cr)ss and amorphous materials were produced in the joint. The self-diffusion activation energy formula [see formula in PDF] can be used to approximate the order of diffusion capacity of elements, which follows in Cr >Fe> Co > Ni.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114852699","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 the present study, the method of frontal observation of the keyhole through the fused quartz window is applied to the dissimilar combinations between stainless steel 316L and different metals chosen to illustrate four typical cases of mismatch in physical properties: a much lower vaporization temperature (316L/magnesium alloy AZ31), a much higher vaporization temperature (316L/pure niobium), a more reflective and conductive metal (316L/aluminum alloy A5754) and an extremely reflective metal (316L/pure copper). A standalone Yb:YAG laser pulse was applied to the dissimilar couple/quartz and metal/quartz joints. Each of these cases was studied using image treatment of the obtained high-speed videos and post-mortem observation of the interaction zone. Basing on the analysis of the physical properties of the metals and their interdependencies, the first criterion of keyhole development in the dissimilar joint is proposed. It is concluded that in case of Yb:YAG laser welding of stainless steel with metals having thermal conductivity ≤200 W · m−1 · K−1, the keyhole development is dominant in the metal having lower vaporization temperature, while for the 316L combinations with the metals having thermal conductivity >200 W · m−1 · K−1, the keyhole development remains dominant on the 316L side, but its progression is slowed down by the neighboring metal.
{"title":"In-situ study of keyhole behavior during a laser pulse applied to the dissimilar metal joint","authors":"I. Tomashchuk, M. Duband, J. Jouvard","doi":"10.1051/metal/2023043","DOIUrl":"https://doi.org/10.1051/metal/2023043","url":null,"abstract":"In the present study, the method of frontal observation of the keyhole through the fused quartz window is applied to the dissimilar combinations between stainless steel 316L and different metals chosen to illustrate four typical cases of mismatch in physical properties: a much lower vaporization temperature (316L/magnesium alloy AZ31), a much higher vaporization temperature (316L/pure niobium), a more reflective and conductive metal (316L/aluminum alloy A5754) and an extremely reflective metal (316L/pure copper). A standalone Yb:YAG laser pulse was applied to the dissimilar couple/quartz and metal/quartz joints. Each of these cases was studied using image treatment of the obtained high-speed videos and post-mortem observation of the interaction zone. Basing on the analysis of the physical properties of the metals and their interdependencies, the first criterion of keyhole development in the dissimilar joint is proposed. It is concluded that in case of Yb:YAG laser welding of stainless steel with metals having thermal conductivity ≤200 W · m−1 · K−1, the keyhole development is dominant in the metal having lower vaporization temperature, while for the 316L combinations with the metals having thermal conductivity >200 W · m−1 · K−1, the keyhole development remains dominant on the 316L side, but its progression is slowed down by the neighboring metal.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115075053","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 study, Fluent software is used to simulate the interaction between temperature and solute fields during the process of vacuum arc remelting. The heredity law of macrosegregation of the easily segregated Fe element between the primary and secondary ingots is examined. The results shows that macrosegregation of the primary ingot has a genetic effect on the macrosegregation of secondary ingots. Compared with the primary ingot, the negative segregation in the surface area of the secondary ingot leads to a certain increase. When the position and direction of the lower part of the primary ingot are unchanged, the negative segregation in the surface area of the secondary ingot exhibits the highest increase, and the negative segregation degree increases by 0.42. When the position and direction of the upper part of the primary ingot remains unchanged, the positive segregation in the core of the secondary ingot exhibits the highest increase, and the positive segregation degree increass by 0.57. When the upper and lower parts of the primary ingot are exchanged and the upper half is downward, the positive segregation degree of the secondary ingot core is reduced by 0.17. When upper and lower parts of the primary ingot switch positions and directions of the upper and lower parts are downward, the center segregation of the secondary ingot is improved when compared to that of the primary ingot, and processing of the primary ingot is not required. This is turn leads to greater significance in actual production.
{"title":"Numerical simulation of macrosegregation heredity on TC4 titanium alloy ingot by vacuum arc remelting","authors":"Jing Zhenquan, Yan-hui Sun, S. Song","doi":"10.1051/metal/2023012","DOIUrl":"https://doi.org/10.1051/metal/2023012","url":null,"abstract":"In this study, Fluent software is used to simulate the interaction between temperature and solute fields during the process of vacuum arc remelting. The heredity law of macrosegregation of the easily segregated Fe element between the primary and secondary ingots is examined. The results shows that macrosegregation of the primary ingot has a genetic effect on the macrosegregation of secondary ingots. Compared with the primary ingot, the negative segregation in the surface area of the secondary ingot leads to a certain increase. When the position and direction of the lower part of the primary ingot are unchanged, the negative segregation in the surface area of the secondary ingot exhibits the highest increase, and the negative segregation degree increases by 0.42. When the position and direction of the upper part of the primary ingot remains unchanged, the positive segregation in the core of the secondary ingot exhibits the highest increase, and the positive segregation degree increass by 0.57. When the upper and lower parts of the primary ingot are exchanged and the upper half is downward, the positive segregation degree of the secondary ingot core is reduced by 0.17. When upper and lower parts of the primary ingot switch positions and directions of the upper and lower parts are downward, the center segregation of the secondary ingot is improved when compared to that of the primary ingot, and processing of the primary ingot is not required. This is turn leads to greater significance in actual production.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129763375","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}
Changqiao Yang, Xiangjun Liu, Ji-chun Yang, Quanhai Yang
The removal and control of inclusions has always been a hot issue in the field of metallurgy, and rare earth modifying is a proven method. However, some rare earth inclusions cannot be accurately judged due to the necessary assumptions for thermodynamic calculations and the lack of certain thermodynamic data. On the other hand, most of the currently reported researches focus on the changes in the morphology of the inclusions, and rarely involve the inherent properties of the inclusions. To address these two deficiencies, this work investigated elaborately the stability, elastic modulus, elastic anisotropy and thermal expansion coefficient of yttrium (Y) inclusions in micro alloyed steels by first-principles calculation. Then, the role of yttrium inclusion in the initial stage of crack initiation was discussed. The results showed that it was practical to judge the possibility of unknown inclusions formation in steel by formation enthalpy. The inclusions were changed from Al2O3 to Y2O3, Y2O2S, YAlO3-Y2Si2O7 composite inclusions with yttrium treatment, which was consistent with the metallographic observations. The bulk modulus (B), shear modulus (G), Young’s modulus (E), and Poisson’s ratio (σ) were calculated in a framework of the Voigte-Reusse-Hill approximation. In light of B/G and σ values, Al2O3 showed apparent brittleness, and the toughness of yttrium inclusions were improved to varying degrees compared to Al2O3 inclusions. Moreover, the order of the degree of elastic anisotropy for these inclusions was Y2Si2O7 > Al2O3 > Y2O3 > Y2O2S > YAlO3. Furthermore, the thermal expansion coefficient of Y2O3, Y2O2S, YAlO3 inclusions at any temperature were greater than that of Al2O3 and were relatively close to that of Fe, whereas, Y2Si2O7 inclusion was much larger than that of Fe. Finally, the difference between yttrium inclusions and iron matrix in the aspect of incompressibility, brittleness, toughness, mechanical anisotropy, and thermal expansion was reduced significantly, thereby improving the consistency of the matrix, this could be used to explain the phenomenon of alleviating stresses concentration and delaying the formation of micro voids.
{"title":"First-principles study on yttrium inclusions in micro alloyed steels","authors":"Changqiao Yang, Xiangjun Liu, Ji-chun Yang, Quanhai Yang","doi":"10.1051/metal/2022063","DOIUrl":"https://doi.org/10.1051/metal/2022063","url":null,"abstract":"The removal and control of inclusions has always been a hot issue in the field of metallurgy, and rare earth modifying is a proven method. However, some rare earth inclusions cannot be accurately judged due to the necessary assumptions for thermodynamic calculations and the lack of certain thermodynamic data. On the other hand, most of the currently reported researches focus on the changes in the morphology of the inclusions, and rarely involve the inherent properties of the inclusions. To address these two deficiencies, this work investigated elaborately the stability, elastic modulus, elastic anisotropy and thermal expansion coefficient of yttrium (Y) inclusions in micro alloyed steels by first-principles calculation. Then, the role of yttrium inclusion in the initial stage of crack initiation was discussed. The results showed that it was practical to judge the possibility of unknown inclusions formation in steel by formation enthalpy. The inclusions were changed from Al2O3 to Y2O3, Y2O2S, YAlO3-Y2Si2O7 composite inclusions with yttrium treatment, which was consistent with the metallographic observations. The bulk modulus (B), shear modulus (G), Young’s modulus (E), and Poisson’s ratio (σ) were calculated in a framework of the Voigte-Reusse-Hill approximation. In light of B/G and σ values, Al2O3 showed apparent brittleness, and the toughness of yttrium inclusions were improved to varying degrees compared to Al2O3 inclusions. Moreover, the order of the degree of elastic anisotropy for these inclusions was Y2Si2O7 > Al2O3 > Y2O3 > Y2O2S > YAlO3. Furthermore, the thermal expansion coefficient of Y2O3, Y2O2S, YAlO3 inclusions at any temperature were greater than that of Al2O3 and were relatively close to that of Fe, whereas, Y2Si2O7 inclusion was much larger than that of Fe. Finally, the difference between yttrium inclusions and iron matrix in the aspect of incompressibility, brittleness, toughness, mechanical anisotropy, and thermal expansion was reduced significantly, thereby improving the consistency of the matrix, this could be used to explain the phenomenon of alleviating stresses concentration and delaying the formation of micro voids.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128313485","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 supersonic jet characteristics of multi-nozzle oxygen lance are the key to the quality of converter steelmaking. It is of great significance to clarify the velocity distribution characteristics of multi nozzle jet centerline to guide the production practice of converter steelmaking. Taking the oxygen lance for 260 t converter as the object, a three-dimensional geometric model is established to study the distribution characteristics of jet centerline velocity under different Mach number and inclination. The synergistic effect of Mach number and orifice inclination on jet attenuation is mainly studied. The mathematical expressions of jet deflection, Mach number and jet inclination are established, the calculation method of jet centerline deviation is proposed, and the previous mathematical model of jet centerline velocity is improved. The results show that the momentum transfer coefficient Kj of multi-nozzle oxygen lance is not only related to Mach number, but also affected by jet inclination. The deviation between the corrected mathematical model and the field measured results is 4.3%.
{"title":"Mathematical model of supersonic jet centerline velocity for multi-nozzle oxygen lance","authors":"Yanxin Li, H. Jia, Guangqiang Liu, Kun Liu","doi":"10.1051/metal/2022069","DOIUrl":"https://doi.org/10.1051/metal/2022069","url":null,"abstract":"The supersonic jet characteristics of multi-nozzle oxygen lance are the key to the quality of converter steelmaking. It is of great significance to clarify the velocity distribution characteristics of multi nozzle jet centerline to guide the production practice of converter steelmaking. Taking the oxygen lance for 260 t converter as the object, a three-dimensional geometric model is established to study the distribution characteristics of jet centerline velocity under different Mach number and inclination. The synergistic effect of Mach number and orifice inclination on jet attenuation is mainly studied. The mathematical expressions of jet deflection, Mach number and jet inclination are established, the calculation method of jet centerline deviation is proposed, and the previous mathematical model of jet centerline velocity is improved. The results show that the momentum transfer coefficient Kj\u0000 of multi-nozzle oxygen lance is not only related to Mach number, but also affected by jet inclination. The deviation between the corrected mathematical model and the field measured results is 4.3%.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129917890","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 characteristics of inclusions have a significant influence on the performance and fatigue life of Ni-based alloy and some cracks usually initiate and propagate from inclusions. High-temperature experiments were carried out at 1823 K to study the effect of Al and Ti addition on the characteristics of oxide inclusions in Ni-based alloy. The size, number, distance, distribution of oxide inclusions and degree of homogeneity in inclusion dispersion in Ni-based alloy with [%Al]i = 0.3–0.7 and [%Ti]i = 0.7–1.2 (i represent initial addition of deoxidant) were analyzed systematically. It is found that the oxide inclusions in alloys with [%Al]i = 0.7, [%Ti]i = 0.7/1.2 had smaller average size of 2.4 µm and distributed more homogeneously. The Ostwald ripening theory and collision model were applied to point out the relationships among compositions of Ni-based alloy, behaviors of oxide inclusions and their characteristics under the condition of no external stirring. The calculated results were in good agreement with experimental results. The mechanism on obtaining fine and dispersed oxide inclusions in Ni-based alloy was summarized.
{"title":"Effect of Al and Ti addition on the characteristics of oxide inclusions in Ni-based superalloy","authors":"Linzhu Wang, Yin Zhang, Chao-yi Chen, Xiang Li, Junqi Li, Shufeng Yang","doi":"10.1051/metal/2023022","DOIUrl":"https://doi.org/10.1051/metal/2023022","url":null,"abstract":"The characteristics of inclusions have a significant influence on the performance and fatigue life of Ni-based alloy and some cracks usually initiate and propagate from inclusions. High-temperature experiments were carried out at 1823 K to study the effect of Al and Ti addition on the characteristics of oxide inclusions in Ni-based alloy. The size, number, distance, distribution of oxide inclusions and degree of homogeneity in inclusion dispersion in Ni-based alloy with [%Al]i = 0.3–0.7 and [%Ti]i = 0.7–1.2 (i represent initial addition of deoxidant) were analyzed systematically. It is found that the oxide inclusions in alloys with [%Al]i = 0.7, [%Ti]i = 0.7/1.2 had smaller average size of 2.4 µm and distributed more homogeneously. The Ostwald ripening theory and collision model were applied to point out the relationships among compositions of Ni-based alloy, behaviors of oxide inclusions and their characteristics under the condition of no external stirring. The calculated results were in good agreement with experimental results. The mechanism on obtaining fine and dispersed oxide inclusions in Ni-based alloy was summarized.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129982268","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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