Rui Mao, Fei Wang, Yuan Xu, Kun Ren, Guangwei Wang
Blast furnace dust (BFD) and converter sludge (CS) were used as raw materials for preparing of cold bonded pellets (CBPs). The results showed that BFD contained high content of C, Fe and harmful element of Zn. Conversely, the CS had more Fe and Ca content and less Zn. BFD particles are mostly large and irregular in shape with poor hydrophilicity, whereas CS particles are generally smaller spherical and could bond together easily. Additionally, the main factors influencing the performance of CBPs are the binder, moisture, and pressing pressure. By controlling the mixing ratio of BFD and CS, selecting the appropriate binder and binder amount, and controlling the moisture and pressure, CBPs with a compressive strength and a falling strength of up to 142.7 N and 8.34 times, respectively, can be prepared, thus meeting the requirements of the rotary hearth furnace and the OxyCup production process.
{"title":"Preparation process of cold bonded pellets with iron-bearing dust and sludge from steel production process","authors":"Rui Mao, Fei Wang, Yuan Xu, Kun Ren, Guangwei Wang","doi":"10.1051/metal/2021077","DOIUrl":"https://doi.org/10.1051/metal/2021077","url":null,"abstract":"Blast furnace dust (BFD) and converter sludge (CS) were used as raw materials for preparing of cold bonded pellets (CBPs). The results showed that BFD contained high content of C, Fe and harmful element of Zn. Conversely, the CS had more Fe and Ca content and less Zn. BFD particles are mostly large and irregular in shape with poor hydrophilicity, whereas CS particles are generally smaller spherical and could bond together easily. Additionally, the main factors influencing the performance of CBPs are the binder, moisture, and pressing pressure. By controlling the mixing ratio of BFD and CS, selecting the appropriate binder and binder amount, and controlling the moisture and pressure, CBPs with a compressive strength and a falling strength of up to 142.7 N and 8.34 times, respectively, can be prepared, thus meeting the requirements of the rotary hearth furnace and the OxyCup production process.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"90 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89958748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Titanium (Ti) alloys are widely used in industrial manufacturing, medical treatment, vehicles, and other fields. When welded with other alloys, due to great differences in physical and chemical properties of these materials, cracks easily appear in the joint, and obtaining stable welded joints is difficult. Results show that brittle intermetallic compounds (IMCs) formed in the welding process could reduce the plasticity of the joint. This review aimed to provide a comprehensive overview of the recent progress in welding and joining of Ti alloy and light alloys and to introduce current research and application. The methods available for welding Ti alloy and light alloys included fusion welding, brazing, diffusion bonding, friction welding and reactive joining. In this study, control methods of brittle IMCs in the welding process of Ti and other alloys and various improvement measures studied at home and abroad are described.
{"title":"A review of dissimilar welding for titanium alloys with light alloys","authors":"Yan Zhang, Deshui Yu, Jianping Zhou, Daqian Sun","doi":"10.1051/METAL/2021011","DOIUrl":"https://doi.org/10.1051/METAL/2021011","url":null,"abstract":"Titanium (Ti) alloys are widely used in industrial manufacturing, medical treatment, vehicles, and other fields. When welded with other alloys, due to great differences in physical and chemical properties of these materials, cracks easily appear in the joint, and obtaining stable welded joints is difficult. Results show that brittle intermetallic compounds (IMCs) formed in the welding process could reduce the plasticity of the joint. This review aimed to provide a comprehensive overview of the recent progress in welding and joining of Ti alloy and light alloys and to introduce current research and application. The methods available for welding Ti alloy and light alloys included fusion welding, brazing, diffusion bonding, friction welding and reactive joining. In this study, control methods of brittle IMCs in the welding process of Ti and other alloys and various improvement measures studied at home and abroad are described.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"3 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90145956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, isothermal and hot corrosion in molten 75 mass% Na2 SO4 +25 mass% NaCl at 900 °C was carried out on an W richen Co-based directionally solidified Co-27.53Cr-9.85W-10.29Ni-0.75Al superalloy. For comparison, K38G with composition of 16.34Cr-4Al-1.77Mo-3.81Ti-2.66W-8.38Co were also conducted under same condition. Isothermal oxidation indicates that Co-based superalloy forms a Co-oxide dispersion chromia scale. However, K38G forms a purer chromia scale due to higher weight percentage ratio of Cr to Al. Under molten Na2 SO4 -NaCl salts, the defects in Ni/Co oxide dispersion chromia layer make it feasible that the molten salt can penetrates along grain boundaries into the internal interface to form internal sulfides, which causes the spallation of scales and significantly decreases its hot corrosion resistance.
{"title":"Oxidation and hot corrosion behavior of a directionally solidified W richen cobalt-based superalloy","authors":"Yue Zhou, C. Mo, Hong Wang","doi":"10.1051/METAL/2021033","DOIUrl":"https://doi.org/10.1051/METAL/2021033","url":null,"abstract":"In this study, isothermal and hot corrosion in molten 75 mass% Na2 SO4 +25 mass% NaCl at 900 °C was carried out on an W richen Co-based directionally solidified Co-27.53Cr-9.85W-10.29Ni-0.75Al superalloy. For comparison, K38G with composition of 16.34Cr-4Al-1.77Mo-3.81Ti-2.66W-8.38Co were also conducted under same condition. Isothermal oxidation indicates that Co-based superalloy forms a Co-oxide dispersion chromia scale. However, K38G forms a purer chromia scale due to higher weight percentage ratio of Cr to Al. Under molten Na2 SO4 -NaCl salts, the defects in Ni/Co oxide dispersion chromia layer make it feasible that the molten salt can penetrates along grain boundaries into the internal interface to form internal sulfides, which causes the spallation of scales and significantly decreases its hot corrosion resistance.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"13 1","pages":"313"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77157369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoyong Gao, Lin Zhang, Lifeng Zhang, Q. Ren, X. Qu
Rare earth metal transfer from slag to alloy and inclusion was investigated by slag-metal reaction method. Rare earth oxide (CeO2) employed in the refining slags was used a sample case. The results show that direct application of rare earth oxide in the slag is an alternative to traditional way which uses pure rare earth metal or rare-earth ferrous alloy to add rare earth in an alloy. Slag-metal reaction method proves to be an effective way to improve the rare earth transfer from slags to alloys with high content of Al. The content of Ce in the alloy increased with the increasing CeO2/Al2O3 mass ratio of the slag. As the Ce concentration of molten alloy increased from 0 to 105 ppm, the Al2O3 type inclusion was changed into cerium oxide, cerium sulfide and cerium oxy-sulfide inclusions. In addition, the morphology of inclusions was transformed from irregular to near spherical. Finally, the mechanism was discussed by thermodynamic analysis.
{"title":"Transfer of rare earth to alloy and inclusion during slag-metal reaction","authors":"Xiaoyong Gao, Lin Zhang, Lifeng Zhang, Q. Ren, X. Qu","doi":"10.1051/metal/2021057","DOIUrl":"https://doi.org/10.1051/metal/2021057","url":null,"abstract":"Rare earth metal transfer from slag to alloy and inclusion was investigated by slag-metal reaction method. Rare earth oxide (CeO2) employed in the refining slags was used a sample case. The results show that direct application of rare earth oxide in the slag is an alternative to traditional way which uses pure rare earth metal or rare-earth ferrous alloy to add rare earth in an alloy. Slag-metal reaction method proves to be an effective way to improve the rare earth transfer from slags to alloys with high content of Al. The content of Ce in the alloy increased with the increasing CeO2/Al2O3 mass ratio of the slag. As the Ce concentration of molten alloy increased from 0 to 105 ppm, the Al2O3 type inclusion was changed into cerium oxide, cerium sulfide and cerium oxy-sulfide inclusions. In addition, the morphology of inclusions was transformed from irregular to near spherical. Finally, the mechanism was discussed by thermodynamic analysis.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"63 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82606350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Functional graded materials (FGMs) have been widely applied in many engineering fields, and are very potential to be the substitutions of dissimilar metal welding joints due to their overall performance. In this work, the Inconel625-high-strength low-alloy (HSLA) Steel FGM was fabricated by wire arc additive manufacturing (WAAM). The chemical composition distribution, microstructure, phase evolution and mechanical properties of the FGM were examined. With the increasing of HSLA Steel, the chemical composition appeared graded distribution, and the primary dendrite spacing was largest in graded region with 20%HSLA Steel and then gradually decreased. And the main microstructure of the FGM transformed from columnar dendrites to equiaxed dendrites. Laves phase precipitated along dendrites boundary when the content of HSLA Steel was lower than 70% and Nb-rich carbides precipitated when the content of HSLA Steel exceeded to 70%. Microhardness and tensile strength gradually decreased with ascending content of HSLA Steel, and had a drastic improvement (159HV to 228HV and 355Mpa to 733Mpa) when proportion of HSLA Steel increased from 70% to 80%.
{"title":"Additive manufacturing of Inconel625-HSLA Steel functionally graded material by wire arc additive manufacturing","authors":"Jiarong Zhang, X. Di, Chengning Li, Xipeng Zhao, Lin Ba, Xin Jiang","doi":"10.1051/metal/2021063","DOIUrl":"https://doi.org/10.1051/metal/2021063","url":null,"abstract":"Functional graded materials (FGMs) have been widely applied in many engineering fields, and are very potential to be the substitutions of dissimilar metal welding joints due to their overall performance. In this work, the Inconel625-high-strength low-alloy (HSLA) Steel FGM was fabricated by wire arc additive manufacturing (WAAM). The chemical composition distribution, microstructure, phase evolution and mechanical properties of the FGM were examined. With the increasing of HSLA Steel, the chemical composition appeared graded distribution, and the primary dendrite spacing was largest in graded region with 20%HSLA Steel and then gradually decreased. And the main microstructure of the FGM transformed from columnar dendrites to equiaxed dendrites. Laves phase precipitated along dendrites boundary when the content of HSLA Steel was lower than 70% and Nb-rich carbides precipitated when the content of HSLA Steel exceeded to 70%. Microhardness and tensile strength gradually decreased with ascending content of HSLA Steel, and had a drastic improvement (159HV to 228HV and 355Mpa to 733Mpa) when proportion of HSLA Steel increased from 70% to 80%.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"110 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81439938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A ceramic cup is often used to prolong the hearth life of a blast furnace (BF). Corundum blocks and mullite blocks are two kinds of refractories widely used for building ceramic cups in China. Therefore, research on the corrosion resistance of these two kinds of refractories is beneficial to realize the BF longevity. In this study, the corrosion behaviours and corrosion mechanisms of molten slag and molten iron on corundum block and mullite block samples were investigated by corrosion tests. The results show that the slag corrosion resistance of corundum block was better than that of mullite block, and the corrosion mechanisms of molten slag on corundum block and mullite block were different. The aggregates fell from the matrix of the corundum sample when the matrix was corroded to a certain degree by slag, and the corrosion rate of slag on the corundum sample was controlled by the diffusive transport rate of a substance and the chemical reaction rate between slag and matrix. However, the aggregate and matrix of the mullite sample was corroded by slag at the same time, and the corrosion rate of slag on the mullite sample was controlled by the diffusive transport rate of Ca through the newly formed reaction layer. Moreover, the corundum block and mullite block had excellent iron corrosion resistance. The high temperature of molten iron led to an in situ reaction to generate a mullite phase in the corundum sample, and the high temperature affected the microstructure of the corundum block and mullite block.
{"title":"Corrosion behaviour and corrosion mechanism of corundum block and mullite block in hearth of blast furnace","authors":"Shun Yao, Heng Zhou, Shengli Wu, Bo Song, M. Kou","doi":"10.1051/metal/2021071","DOIUrl":"https://doi.org/10.1051/metal/2021071","url":null,"abstract":"A ceramic cup is often used to prolong the hearth life of a blast furnace (BF). Corundum blocks and mullite blocks are two kinds of refractories widely used for building ceramic cups in China. Therefore, research on the corrosion resistance of these two kinds of refractories is beneficial to realize the BF longevity. In this study, the corrosion behaviours and corrosion mechanisms of molten slag and molten iron on corundum block and mullite block samples were investigated by corrosion tests. The results show that the slag corrosion resistance of corundum block was better than that of mullite block, and the corrosion mechanisms of molten slag on corundum block and mullite block were different. The aggregates fell from the matrix of the corundum sample when the matrix was corroded to a certain degree by slag, and the corrosion rate of slag on the corundum sample was controlled by the diffusive transport rate of a substance and the chemical reaction rate between slag and matrix. However, the aggregate and matrix of the mullite sample was corroded by slag at the same time, and the corrosion rate of slag on the mullite sample was controlled by the diffusive transport rate of Ca through the newly formed reaction layer. Moreover, the corundum block and mullite block had excellent iron corrosion resistance. The high temperature of molten iron led to an in situ reaction to generate a mullite phase in the corundum sample, and the high temperature affected the microstructure of the corundum block and mullite block.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"34 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77291741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To reduce the Mn vaporization during recycling rejected electrolytic manganese metal by electroslag remelting, it is proposed to reduce the temperature of molten slag pool, but which leads to the degradation of slag desulfurization. The desulfurization by interaction between CaF2 –CaO–Al2 O3 –Na2 O slag and rejected electrolytic manganese metal scrap was studied from the view of thermodynamics in this study. The results show that sulfur distribution ratio decreases with increase of CaF2 content, and increases with the increase of Na2 O content and temperature. Na2 O increases sulfur distribution ratio of slag by increasing CaO activity. Na2 O addition in CaF2 –CaO–Al2 O3 –Na2 O slag can enhance desulfurization ability of slag due to the larger sulfur distribution ratio and lower viscosity. Thus, sulfur content in test of slag T3 bearing 45.8 wt% CaF2 -23.2 wt% CaO-22.7 wt% Al2 O3 -8.3 wt% Na2 O is much lower than that of slag without Na2 O, implying that 45.8 wt% CaF2 -23.2 wt% CaO-22.7 wt% Al2 O3 -8.3 wt%Na2 O slag is the promising slag for recycling rejected electrolytic manganese metal by ESR.
{"title":"Effect of slag composition on desulfurization during recycling rejected electrolytic manganese metal by electroslag remelting","authors":"Yu Liu, Guangqiang Li, Qiang Wang, Ru Lu, Xijie Wang, Yufeng Tian","doi":"10.1051/METAL/2021019","DOIUrl":"https://doi.org/10.1051/METAL/2021019","url":null,"abstract":"To reduce the Mn vaporization during recycling rejected electrolytic manganese metal by electroslag remelting, it is proposed to reduce the temperature of molten slag pool, but which leads to the degradation of slag desulfurization. The desulfurization by interaction between CaF2 –CaO–Al2 O3 –Na2 O slag and rejected electrolytic manganese metal scrap was studied from the view of thermodynamics in this study. The results show that sulfur distribution ratio decreases with increase of CaF2 content, and increases with the increase of Na2 O content and temperature. Na2 O increases sulfur distribution ratio of slag by increasing CaO activity. Na2 O addition in CaF2 –CaO–Al2 O3 –Na2 O slag can enhance desulfurization ability of slag due to the larger sulfur distribution ratio and lower viscosity. Thus, sulfur content in test of slag T3 bearing 45.8 wt% CaF2 -23.2 wt% CaO-22.7 wt% Al2 O3 -8.3 wt% Na2 O is much lower than that of slag without Na2 O, implying that 45.8 wt% CaF2 -23.2 wt% CaO-22.7 wt% Al2 O3 -8.3 wt%Na2 O slag is the promising slag for recycling rejected electrolytic manganese metal by ESR.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"5 1","pages":"206"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85168413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Electric Arc Furnace (EAF) steelmaking the main chemical reaction is the decarburization reaction. This reaction is promoted by the injection of oxygen using supersonic or coherent jets and further chemical reaction with dissolved carbon in liquid steel at high temperatures. A 3D mathematical model to describe the effect of the injection angle, oxygen gas flow rate and number of lances on the decarburization kinetics of molten steel, in the absence of the top slag layer has been developed. The model has been validated using experimental data reported in the literature. The model shows that the decarburization kinetics is promoted by decreasing the injection angle from the horizontal, condition that improves both bath movement and reaction kinetics. These findings suggest that current injection angles in industrial EAF’s can be decreased in order to improve the decarburization rate. The main mechanism is the effect of the gas jet on the motion of the liquid. Taking into consideration that decreasing the injection angle from the horizontal promotes splashing, the numerical model predictions are employed to suggest alternative solutions in order to reach high decarburization rates.
{"title":"CFD study on the effect of the oxygen lance inclination angle on the decarburization kinetics of liquid steel in the EAF","authors":"M. Ramírez-Argáez, A. Conejo","doi":"10.1051/metal/2021069","DOIUrl":"https://doi.org/10.1051/metal/2021069","url":null,"abstract":"In Electric Arc Furnace (EAF) steelmaking the main chemical reaction is the decarburization reaction. This reaction is promoted by the injection of oxygen using supersonic or coherent jets and further chemical reaction with dissolved carbon in liquid steel at high temperatures. A 3D mathematical model to describe the effect of the injection angle, oxygen gas flow rate and number of lances on the decarburization kinetics of molten steel, in the absence of the top slag layer has been developed. The model has been validated using experimental data reported in the literature. The model shows that the decarburization kinetics is promoted by decreasing the injection angle from the horizontal, condition that improves both bath movement and reaction kinetics. These findings suggest that current injection angles in industrial EAF’s can be decreased in order to improve the decarburization rate. The main mechanism is the effect of the gas jet on the motion of the liquid. Taking into consideration that decreasing the injection angle from the horizontal promotes splashing, the numerical model predictions are employed to suggest alternative solutions in order to reach high decarburization rates.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"119 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86183908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the mechanical properties of two welded joints under different lapping orders (B1500HS-1.4 mm/B1500HS-1.6 mm/DC06, denoted as type I; B1500HS-1.4 mm/DC06/B1500HS-1.6 mm, denoted type II) were compared. The nugget formation mechanism was analysed by a coupled electrical-thermal finite element model (FEM). It is found that different lapping orders significantly affect the mechanical properties of three-sheet RSW joints. All RSW joints tend to fail in the pull-out or tearing failure mode. The peak load of the two interfaces of type II RSW joint is more balanced, and the failure load of which is much higher than that of the type I RSW joint; The warpage was observed at type I welded joint. Considered the load-carrying capacity, type II was excellent. The simulation results indicate that the diameter of the weld nugget at the upper interface of the type I RSW joint was larger than that on the other interfaces, which agree well with the experimental results. The nugget formation mechanism of dissimilar high strength steel three-sheet RSW joint was obtained that forming the nugget firstly from two interfaces and final formed nuggets were asymmetric.
{"title":"Effect of different lapping orders on mechanical performance and nugget forming process for three-sheet dissimilar resistance spot welding joints between DC06 and unequal-thickness hot-stamped B1500HS steel sheets","authors":"Mao Xin, Zhi Cheng, Q. Zhu, Wurong Wang, Xi-cheng Wei, Yangyang Zhao","doi":"10.1051/METAL/2020094","DOIUrl":"https://doi.org/10.1051/METAL/2020094","url":null,"abstract":"In this study, the mechanical properties of two welded joints under different lapping orders (B1500HS-1.4 mm/B1500HS-1.6 mm/DC06, denoted as type I; B1500HS-1.4 mm/DC06/B1500HS-1.6 mm, denoted type II) were compared. The nugget formation mechanism was analysed by a coupled electrical-thermal finite element model (FEM). It is found that different lapping orders significantly affect the mechanical properties of three-sheet RSW joints. All RSW joints tend to fail in the pull-out or tearing failure mode. The peak load of the two interfaces of type II RSW joint is more balanced, and the failure load of which is much higher than that of the type I RSW joint; The warpage was observed at type I welded joint. Considered the load-carrying capacity, type II was excellent. The simulation results indicate that the diameter of the weld nugget at the upper interface of the type I RSW joint was larger than that on the other interfaces, which agree well with the experimental results. The nugget formation mechanism of dissimilar high strength steel three-sheet RSW joint was obtained that forming the nugget firstly from two interfaces and final formed nuggets were asymmetric.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"11 1","pages":"112"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83232359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the formability behavior of dual-phase (DP) steel subjected to friction stir process (FSP), using a miniaturized Erichsen test. The friction stir process yielded a refined microstructure, which consisted of lath martensite and fine ferrite, as a result of dynamic recrystallization (DRX) and phase transformation. Both yield and tensile strength were significantly increased via the grain refinement and increasing martensite fraction. Biaxial formability behavior of the friction stir processed sample exhibited a decline as the Erichsen index (EI) decreased from 2.7 mm to 2.2 mm. However, the required punch load (FEI) increased compatibly with the strength value after FSP. The grain refinement caused by FSP led to an improvement in the orange peel effect, defined as a negative effect of increased surface roughness after metal forming. The value of mean roughness in the free dome surface of the FSPed sample decreased from 4.90 μm to 2.62 μm. It can be concluded that the roughening with the orange peel effect on free surfaces of stretched metal can be eliminated by the friction stir process.
{"title":"Formability behavior of friction stir processed dual phase steel","authors":"S. M. Aktarer, T. Küçükömeroğlu","doi":"10.1051/metal/2021083","DOIUrl":"https://doi.org/10.1051/metal/2021083","url":null,"abstract":"This study investigated the formability behavior of dual-phase (DP) steel subjected to friction stir process (FSP), using a miniaturized Erichsen test. The friction stir process yielded a refined microstructure, which consisted of lath martensite and fine ferrite, as a result of dynamic recrystallization (DRX) and phase transformation. Both yield and tensile strength were significantly increased via the grain refinement and increasing martensite fraction. Biaxial formability behavior of the friction stir processed sample exhibited a decline as the Erichsen index (EI) decreased from 2.7 mm to 2.2 mm. However, the required punch load (FEI) increased compatibly with the strength value after FSP. The grain refinement caused by FSP led to an improvement in the orange peel effect, defined as a negative effect of increased surface roughness after metal forming. The value of mean roughness in the free dome surface of the FSPed sample decreased from 4.90 μm to 2.62 μm. It can be concluded that the roughening with the orange peel effect on free surfaces of stretched metal can be eliminated by the friction stir process.","PeriodicalId":18527,"journal":{"name":"Metallurgical Research & Technology","volume":"44 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88656096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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