Welding research of A6N01S-T5 aluminum alloy profile for high-speed train was done by using laser-MIG hybrid welding and MIG welding individually. And the weld appearance,welding distortion,mechanical properties of th...Welding research of A6N01S-T5 aluminum alloy profile for high-speed train was done by using laser-MIG hybrid welding and MIG welding individually. And the weld appearance,welding distortion,mechanical properties of the joints and microstructures were analyzed. The test results demonstrated that high-efficient welding for the profile can be achieved by using laser-MIG hybrid welding,the speed of which can be over 3. 0 m/min. The processing had a good gap bridging ability,even if the gap of the butt joint was up to 2. 0 mm,a good weld appearance can also be got. While the hybrid welding speed was greater than 2. 5 m/min,the welding distortion of the laser-tandem MIG hybrid joints was just about 33% of that of the MIG joints,but the welding efficiency was over 3 times of MIG welding. And tensile strength of the hybrid joints was 85% of that of A6N01S-T5 base metal,9% higher than that of the MIG joints. Fatigue properties was tested individually with pulsed tensile fatigue method in the condition of 1 × 10~7 lifetime. The test results demonstrated that the fatigue strength of the joints was a little lower than that of base material,which could be up to 115 MPa. But the fatigue strength of hybrid welding joints was 107. 5 MPa,which was 23% higher than 87 MPa of MIG welding joints.展开更多
The inner hole parts played an oriented or supporting role in engineering machinery and equipment,which are prone to appear surface damages such as wear,strain and corrosion. The precise pulse plasma arc powder weldin...The inner hole parts played an oriented or supporting role in engineering machinery and equipment,which are prone to appear surface damages such as wear,strain and corrosion. The precise pulse plasma arc powder welding method is used for surface damage repairing of inner hole parts in this paper. The working principle and process of the technology are illustrated,and the microstructure and property of repairing layer by precise pulse plasma powder welding and CO2 gas shielded welding are tested and observed by microscope,micro hardness tester and X-ray residual stress tester etc. Results showed that the substrate deformation of thin-walled inner hole parts samples by precise pulse plasma powder welding is relatively small. The repair layer and substrate is metallurgical bonding,the transition zones( including fusion zone and heat affected zone) are relatively narrow and the welding quality is good. It showed that the thin-walled inner hole parts can be repaired by this technology and equipment.展开更多
The application status of friction stir welding technology is introduced,and the application research of advanced FSW technology in the manufacture of high-speed electric multiple unit aluminum alloy body is analyzed,...The application status of friction stir welding technology is introduced,and the application research of advanced FSW technology in the manufacture of high-speed electric multiple unit aluminum alloy body is analyzed,including the application of traditional friction stir welding technology to a combination of a lap joint and butt joint,and butt joint of large thick plate by both sides process,also introduces bobbin-tool friction stir welding to a butt joint and three-dimensional space curved friction stir welding to T-joint. At the same time the future development trend of new FSW technology derived from traditional FSW technology in rail vehicle manufacturing industry is put forward. As the fast developing of critical technology used on railway vehicles,quick applying advanced welding technology will affect products quality,manufacturing cost and production cycle time directly,and it certainly will be one of the approaches to develop markets by all the railway vehicles manufacturing enterprises.展开更多
Friction element welding technology is rich of flow drill screws combined with friction welding technology and is developed for the hot-forming steel plate and aluminum alloy welding of car body-in-white.In this paper...Friction element welding technology is rich of flow drill screws combined with friction welding technology and is developed for the hot-forming steel plate and aluminum alloy welding of car body-in-white.In this paper,the principle of RES welding technology,equipment,technical characteristics,application condition and welding parameters are analyzed systematically.Moreover,the changing laws of welding parameters and welded joint quality control standards are described,which provides the necessary technical support for safety and light-weight car body design requirements.This study has high practical application value,and enriches the automobile body joining technology.展开更多
In recent years,the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has fi...In recent years,the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China,and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc.,the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment,laser-arc hybrid welding technology for pipeline field welding will be available soon.展开更多
This study aims to conduct the weldability test for a high-strength structural steel,Bweldy620 QL6,developed by Baosteel.This steel was subjected to welding,and the effects of two kinds of shielding gas,a binary gas o...This study aims to conduct the weldability test for a high-strength structural steel,Bweldy620 QL6,developed by Baosteel.This steel was subjected to welding,and the effects of two kinds of shielding gas,a binary gas of 80%Ar +20%CO_2 and ternary gas of 90% Ar +8%CO_2 +2%O_2,on the performance of the welded joints of high-strength heavy steel were compared.The results show that Bweldy620 QL6 has good weldability,and the joints obtained using binary gas and ternary gas meet common requirements.展开更多
Five experimental self-shielded flux cored wires are fabricated with different amount of Fe2O3 in the flux. The effect of Fe2O3 on welding technology and mechanical properties of weld metals deposited by these wires a...Five experimental self-shielded flux cored wires are fabricated with different amount of Fe2O3 in the flux. The effect of Fe2O3 on welding technology and mechanical properties of weld metals deposited by these wires are studied. The results show that with the increase of Fe2O3 in the mix, the melting point of the pretreated mix is increased. LiBaF3 and BaFe12O19, which are very low in inherent moisture, are formed after the pretreatment. The mechanical properties are evaluated to the weld metals. The low temperature notch toughness of the weld metals is increased linearly with the Fe2O3 content in the flux due to the balance between Fe2O3 and residual Al in the weld metal. The optimum Fe2O3 content in flux is 2.5%～3.5 %.展开更多
In this study,the welding technology of the hot-rolled extra-high-strength steel,BS960QC,has been comprehensively investigated.Analysis has been made on the weldability,the different welding procedures,the mechanical ...In this study,the welding technology of the hot-rolled extra-high-strength steel,BS960QC,has been comprehensively investigated.Analysis has been made on the weldability,the different welding procedures,the mechanical properties,and the fatigue properties,and a set of recommendation guidelines have been proposed for evaluating the welded joints of the extra-high-strength steel.The research and results indicate that the hot-rolled extra-high-strength steel,BS960QC,has good weldability and an excellent adaptability to welding procedures.Further,the excellent mechanical properties and fatigue properties of the welded joints,which can be achieved by using optimized welding procedures,can completely meet the technical requirements of the construction machinery industry.展开更多
In this paper,the spot welding technology of a new kind of 22 MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder.Through a series of technology and test experiments,we ha...In this paper,the spot welding technology of a new kind of 22 MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder.Through a series of technology and test experiments,we have obtained the optimal spot welding technological parameter condition.According to the results,the relations among spot welding technological parameter,welding nugget,mechanical property and fracture mode were discussed.The effects of all the welding parameters such as welding current,welding time and electrode force on the quality of joint can be boiled down to one thing—the diameter of welding nugget.The experimental results showed that welding nugget diameter determines the mechanical property of spot welding joint and the relation between welding nugget diameter and the mechanical property of joint presents a kind of linear mathematic representation.There are two typical fracture models of 22 MnMoB hot stamping quenched steel sheet,i.e.,interfacial fracture and nugget pullout.Other than mild steel or normal high strength steel,in the shearing tensile test,hot stamping quenched steel has a great tendency to fail in interfacial mode due to the effects of high strength matrix structure,welding soft zone and the porosity level of fusion zone.展开更多
Railway signal transmission is the key to ensure the safe and normal operation of the train. The railway connecting line for signal transmission is important equipment to guarantee the railway signal transmission and ...Railway signal transmission is the key to ensure the safe and normal operation of the train. The railway connecting line for signal transmission is important equipment to guarantee the railway signal transmission and reduce the imbalance of electric current. In point of engineering application, the explosive welding technology of railway connecting line is studied theoretically, the appearance, tensile strength, micro configuration of welding junction , welding area are detected after explosive welding. Experimental and detecting results show that the connecting quality of explosive welding is reliable, which lays the foundation for the engineering practice of technology.展开更多
The characteristics of temperatures, stresses and strains fields have been studied numerically for a titanium alloy sheet welded with an improved gas tungsten arc welding method, in which a trailing spot heat sink is ...The characteristics of temperatures, stresses and strains fields have been studied numerically for a titanium alloy sheet welded with an improved gas tungsten arc welding method, in which a trailing spot heat sink is introduced to control the welding stress and distortion. The impinging jet model is employed to describe the intense heat transfer between the cooling media and the top surface of the workpiece. The influence of the distance between arc and heat sink is investigated. Results show that there is an ideal range of distance. Using the ideal distance, a low stress and no distortion welding structure can be derived.展开更多
With the continuous development of society,the gradual improvement of mechanical automation technology has been introduced into the production of many enterprises in China,which has had a great impact on the increase ...With the continuous development of society,the gradual improvement of mechanical automation technology has been introduced into the production of many enterprises in China,which has had a great impact on the increase of China′s gross national product.Applying mechanical automation technology greatly saves labor cost,improves working efficiency and the production level of enterprises,effectively promotes the development of enterprises,and increases the enterprise′s income.In addition,mechanical automation technology is closely related to product production⁃related technology and plays a very important role in the innovation of enterprise products.This article will briefly introduce the design and application of automation technology in welding seam welding design,and understand the development background,research status,current application and simulation design.展开更多
Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction indu...Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.展开更多
By considering the joint effects of the Kelvin-Helmholtz(KH) and Rayleigh-Taylor(RT) instabilities, this paper presents an interpretation of the wavy patterns that occur in explosive welding. It is assumed that the el...By considering the joint effects of the Kelvin-Helmholtz(KH) and Rayleigh-Taylor(RT) instabilities, this paper presents an interpretation of the wavy patterns that occur in explosive welding. It is assumed that the elasticity of the material at the interface effectively determines the wavelength, because explosive welding is basically a solid-state welding process. To this end, an analytical model of elastic hydrodynamic instabilities is proposed, and the most unstable mode is selected in the solid phase. Similar approaches have been widely used to study the interfacial behavior of solid metals in high-energy-density physics. By comparing the experimental and theoretical results, it is concluded that thermal softening,which significantly reduces the shear modulus, is necessary and sufficient for successful welding. The thermal softening is verified by theoretical analysis of the increase in temperature due to the impacting and sliding of the flyer and base plates, and some experimental observations are qualitatively validated.In summary, the combined effect of the KH and RT instabilities in solids determines the wavy morphology, and our theoretical results are in good qualitative agreement with experimental and numerical observations.展开更多
基金supported by National Natural Science Foundation of China(61640423)Additive Manufacturing&Laser Manufacturing of China(2016YFB1102100)High-end CNC Machine Tools&Basic Manufacturing Equipment of China(2016ZX04003002)
文摘Welding research of A6N01S-T5 aluminum alloy profile for high-speed train was done by using laser-MIG hybrid welding and MIG welding individually. And the weld appearance,welding distortion,mechanical properties of the joints and microstructures were analyzed. The test results demonstrated that high-efficient welding for the profile can be achieved by using laser-MIG hybrid welding,the speed of which can be over 3. 0 m/min. The processing had a good gap bridging ability,even if the gap of the butt joint was up to 2. 0 mm,a good weld appearance can also be got. While the hybrid welding speed was greater than 2. 5 m/min,the welding distortion of the laser-tandem MIG hybrid joints was just about 33% of that of the MIG joints,but the welding efficiency was over 3 times of MIG welding. And tensile strength of the hybrid joints was 85% of that of A6N01S-T5 base metal,9% higher than that of the MIG joints. Fatigue properties was tested individually with pulsed tensile fatigue method in the condition of 1 × 10~7 lifetime. The test results demonstrated that the fatigue strength of the joints was a little lower than that of base material,which could be up to 115 MPa. But the fatigue strength of hybrid welding joints was 107. 5 MPa,which was 23% higher than 87 MPa of MIG welding joints.
文摘The inner hole parts played an oriented or supporting role in engineering machinery and equipment,which are prone to appear surface damages such as wear,strain and corrosion. The precise pulse plasma arc powder welding method is used for surface damage repairing of inner hole parts in this paper. The working principle and process of the technology are illustrated,and the microstructure and property of repairing layer by precise pulse plasma powder welding and CO2 gas shielded welding are tested and observed by microscope,micro hardness tester and X-ray residual stress tester etc. Results showed that the substrate deformation of thin-walled inner hole parts samples by precise pulse plasma powder welding is relatively small. The repair layer and substrate is metallurgical bonding,the transition zones( including fusion zone and heat affected zone) are relatively narrow and the welding quality is good. It showed that the thin-walled inner hole parts can be repaired by this technology and equipment.
基金supported by Changchun Science and Technology Innovation"Double Tenth Project"(Grant No.17SS024)Technical Development Project of CRRC Changchun Railway Vehicles Co.,Ltd(Grant No.16GCZX006)
文摘The application status of friction stir welding technology is introduced,and the application research of advanced FSW technology in the manufacture of high-speed electric multiple unit aluminum alloy body is analyzed,including the application of traditional friction stir welding technology to a combination of a lap joint and butt joint,and butt joint of large thick plate by both sides process,also introduces bobbin-tool friction stir welding to a butt joint and three-dimensional space curved friction stir welding to T-joint. At the same time the future development trend of new FSW technology derived from traditional FSW technology in rail vehicle manufacturing industry is put forward. As the fast developing of critical technology used on railway vehicles,quick applying advanced welding technology will affect products quality,manufacturing cost and production cycle time directly,and it certainly will be one of the approaches to develop markets by all the railway vehicles manufacturing enterprises.
文摘Friction element welding technology is rich of flow drill screws combined with friction welding technology and is developed for the hot-forming steel plate and aluminum alloy welding of car body-in-white.In this paper,the principle of RES welding technology,equipment,technical characteristics,application condition and welding parameters are analyzed systematically.Moreover,the changing laws of welding parameters and welded joint quality control standards are described,which provides the necessary technical support for safety and light-weight car body design requirements.This study has high practical application value,and enriches the automobile body joining technology.
文摘In recent years,the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China,and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc.,the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment,laser-arc hybrid welding technology for pipeline field welding will be available soon.
文摘This study aims to conduct the weldability test for a high-strength structural steel,Bweldy620 QL6,developed by Baosteel.This steel was subjected to welding,and the effects of two kinds of shielding gas,a binary gas of 80%Ar +20%CO_2 and ternary gas of 90% Ar +8%CO_2 +2%O_2,on the performance of the welded joints of high-strength heavy steel were compared.The results show that Bweldy620 QL6 has good weldability,and the joints obtained using binary gas and ternary gas meet common requirements.
文摘Five experimental self-shielded flux cored wires are fabricated with different amount of Fe2O3 in the flux. The effect of Fe2O3 on welding technology and mechanical properties of weld metals deposited by these wires are studied. The results show that with the increase of Fe2O3 in the mix, the melting point of the pretreated mix is increased. LiBaF3 and BaFe12O19, which are very low in inherent moisture, are formed after the pretreatment. The mechanical properties are evaluated to the weld metals. The low temperature notch toughness of the weld metals is increased linearly with the Fe2O3 content in the flux due to the balance between Fe2O3 and residual Al in the weld metal. The optimum Fe2O3 content in flux is 2.5%～3.5 %.
文摘In this study,the welding technology of the hot-rolled extra-high-strength steel,BS960QC,has been comprehensively investigated.Analysis has been made on the weldability,the different welding procedures,the mechanical properties,and the fatigue properties,and a set of recommendation guidelines have been proposed for evaluating the welded joints of the extra-high-strength steel.The research and results indicate that the hot-rolled extra-high-strength steel,BS960QC,has good weldability and an excellent adaptability to welding procedures.Further,the excellent mechanical properties and fatigue properties of the welded joints,which can be achieved by using optimized welding procedures,can completely meet the technical requirements of the construction machinery industry.
文摘In this paper,the spot welding technology of a new kind of 22 MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder.Through a series of technology and test experiments,we have obtained the optimal spot welding technological parameter condition.According to the results,the relations among spot welding technological parameter,welding nugget,mechanical property and fracture mode were discussed.The effects of all the welding parameters such as welding current,welding time and electrode force on the quality of joint can be boiled down to one thing—the diameter of welding nugget.The experimental results showed that welding nugget diameter determines the mechanical property of spot welding joint and the relation between welding nugget diameter and the mechanical property of joint presents a kind of linear mathematic representation.There are two typical fracture models of 22 MnMoB hot stamping quenched steel sheet,i.e.,interfacial fracture and nugget pullout.Other than mild steel or normal high strength steel,in the shearing tensile test,hot stamping quenched steel has a great tendency to fail in interfacial mode due to the effects of high strength matrix structure,welding soft zone and the porosity level of fusion zone.
基金Shanxi Province Key Technology R&D Program(2006031161)
文摘Railway signal transmission is the key to ensure the safe and normal operation of the train. The railway connecting line for signal transmission is important equipment to guarantee the railway signal transmission and reduce the imbalance of electric current. In point of engineering application, the explosive welding technology of railway connecting line is studied theoretically, the appearance, tensile strength, micro configuration of welding junction , welding area are detected after explosive welding. Experimental and detecting results show that the connecting quality of explosive welding is reliable, which lays the foundation for the engineering practice of technology.
基金This work is supported by The Aeronautical Funds of China
文摘The characteristics of temperatures, stresses and strains fields have been studied numerically for a titanium alloy sheet welded with an improved gas tungsten arc welding method, in which a trailing spot heat sink is introduced to control the welding stress and distortion. The impinging jet model is employed to describe the intense heat transfer between the cooling media and the top surface of the workpiece. The influence of the distance between arc and heat sink is investigated. Results show that there is an ideal range of distance. Using the ideal distance, a low stress and no distortion welding structure can be derived.
文摘With the continuous development of society,the gradual improvement of mechanical automation technology has been introduced into the production of many enterprises in China,which has had a great impact on the increase of China′s gross national product.Applying mechanical automation technology greatly saves labor cost,improves working efficiency and the production level of enterprises,effectively promotes the development of enterprises,and increases the enterprise′s income.In addition,mechanical automation technology is closely related to product production⁃related technology and plays a very important role in the innovation of enterprise products.This article will briefly introduce the design and application of automation technology in welding seam welding design,and understand the development background,research status,current application and simulation design.
文摘Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.
基金the National Natural Science Foundation of China(Grant Nos.12002037 and 12141201).
文摘By considering the joint effects of the Kelvin-Helmholtz(KH) and Rayleigh-Taylor(RT) instabilities, this paper presents an interpretation of the wavy patterns that occur in explosive welding. It is assumed that the elasticity of the material at the interface effectively determines the wavelength, because explosive welding is basically a solid-state welding process. To this end, an analytical model of elastic hydrodynamic instabilities is proposed, and the most unstable mode is selected in the solid phase. Similar approaches have been widely used to study the interfacial behavior of solid metals in high-energy-density physics. By comparing the experimental and theoretical results, it is concluded that thermal softening,which significantly reduces the shear modulus, is necessary and sufficient for successful welding. The thermal softening is verified by theoretical analysis of the increase in temperature due to the impacting and sliding of the flyer and base plates, and some experimental observations are qualitatively validated.In summary, the combined effect of the KH and RT instabilities in solids determines the wavy morphology, and our theoretical results are in good qualitative agreement with experimental and numerical observations.
