The joining of Mg alloy to steel was realized by metal inert-gas arc welding, and the weld thermal cycle characteristics and Mg-steel joints were investigated. The results show that the temperature distribution in the...The joining of Mg alloy to steel was realized by metal inert-gas arc welding, and the weld thermal cycle characteristics and Mg-steel joints were investigated. The results show that the temperature distribution in the joints is uneven. Mg alloy welds present a fine equiaxed grain structure. There exists a transition layer consisting mainly of AlFe, AlFe3 and Mg（Fe, Al）2O4 phases at Mg/steel interface, and it is the weakest link in Mg？steel joints. The welding heat input and weld Al content have the significant effect on the joint strength. The joint strength increases with increasing the heat input from 1680 J/cm to 2093 J/cm, due to promoting Mg/steel interface reaction. When weld Al content is increased to 6.20%, the joint strength reaches 192 MPa, 80% of Mg alloy base metal strength. It is favorable to select the suitable welding heat input and weld Al content for improving joint strength.展开更多
Zincalume steel(G550)is commonly used in various construction fields because of its high corrosion resistance and good mechanical properties.In recent years,a number of steel companies have massively produced zincalum...Zincalume steel(G550)is commonly used in various construction fields because of its high corrosion resistance and good mechanical properties.In recent years,a number of steel companies have massively produced zincalume steel(G550)with large volumes of waste.For the reduction of massive industrial wastes,the zincalume steel(G550)was welded in the lap joint configuration using different welding parameters in the metal inert gas(MIG)welding and laser beam welding(LBW)process in this study.The MIG welding and LBW are more welcomed welding methods due to their high efficiency and low cost.However,they are different as the LBW offers welding speed three to five times faster than MIG welding,while LBW’s heat transfer to workpieces is much less than MIG welding,which can avoid some distortions.The microstructure of zincalume steel(G550)was investigated using scanning electron microscopy(SEM)and the microstructure characterizations of welded specimens were analyzed.The experiment found the columnar dendrites extended under the heat flow direction during the MIG welding and LBW process.Thus,the columnar grains were formed in between the equiaxed zone and fusion zone(FZ)at high heat input and slow cooling rate.Moreover,the grain size of FZ was comparatively smaller than heat affected zone(HAZ)and base metal(BM).展开更多
Gas metal arc welding(GMAW)is also referred as the metal inert gas(MIG)welding which is a process of welding done by the formation of an electric arc between the consumable wire electrode and the workpiece.Through the...Gas metal arc welding(GMAW)is also referred as the metal inert gas(MIG)welding which is a process of welding done by the formation of an electric arc between the consumable wire electrode and the workpiece.Through the welding process,a continuous flow of inert gas is supplied,and it avoids the weld being subjected to react with atmospheric air.The process can be automatic or semi-automatic where the main input parameters like current and the voltage can be direct and constant,respectively.Not only the current and voltage the welding quality depends on some more input parameters such as arc gap,velocity,and temperature.In this paper,we explain about a setup which is capable of real-time monitoring of input parameters mentioned above and selecting the best MIG welding parameters for the mild steel.The setup is composed of several sensors and microcontrollers for the collection and the measurement of the input parameters.The samples were categorized according to the federate and the voltage adjustment of the selected welding machine.Then the final objective was to identify the samples of the weld with different parameter changes which are monitored through the system.For the analysis,the samples were subjected to tensile and hardness tests,and microstructure tests to find the dependence of the input parameters which effect for the weld quality.Finally,the experimental results verified the effectiveness of the system for the selection of the quality weld.展开更多
实现铝钢良好连接的关键是有效控制焊接热输入,尽量降低中间层铝铁金属间化合物的厚度,一般认为中间层金属间化合物厚度小于10μm时铝钢接头质量良好。提出旁路耦合电弧熔钎焊方法,通过调节旁路电弧电流的大小来控制焊接热输入。在优化...实现铝钢良好连接的关键是有效控制焊接热输入,尽量降低中间层铝铁金属间化合物的厚度,一般认为中间层金属间化合物厚度小于10μm时铝钢接头质量良好。提出旁路耦合电弧熔钎焊方法,通过调节旁路电弧电流的大小来控制焊接热输入。在优化控制系统和工艺参数的基础上采用脉冲旁路耦合电弧焊方法将铝镁合金ER5356堆焊到304不锈钢板上,获得结合良好的焊缝。对焊接接头进行扫描电镜(Scanning electron microscope,SEM)、能量色散光谱仪(Energy dispersive spectrometry,EDS)分析,结果表明:铝与不锈钢焊接接头中间层金属间化合物平均厚度约为8μm,小于10μm的临界厚度;脉冲旁路耦合电弧焊方法能够实现铝钢的连接,是一种新型低成本低热输入电弧焊方法。展开更多
提出双旁路耦合电弧熔化极惰性气体保护(Dual bypass metal inert-gas,DB-MIG)电弧焊方法并建立试验系统。该方法以传统熔化极惰性气体保护焊接电弧为主弧,引入两路对称的电流可控的非熔化极旁路电弧并与主弧形成耦合电弧进行焊接。由...提出双旁路耦合电弧熔化极惰性气体保护(Dual bypass metal inert-gas,DB-MIG)电弧焊方法并建立试验系统。该方法以传统熔化极惰性气体保护焊接电弧为主弧,引入两路对称的电流可控的非熔化极旁路电弧并与主弧形成耦合电弧进行焊接。由于旁路电弧的分流作用,在保持较高焊丝熔化电流的同时可有效降低母材输入电流,并且旁路电弧力的作用对熔滴过渡也有显著的影响。设计专用的窄带滤光系统,实现无激光背光的焊接熔滴过渡行为的高速摄像,获得不同旁路电流参数条件下的铝合金DB-MIG焊熔滴过渡的高速摄影图像并进行分析。试验结果表明总电流恒定的情况下,熔滴过渡形态随旁路电弧电流参数改变而改变。对DB-MIG焊条件下作用于熔滴上的电弧力的分布进行理论分析,解释试验现象,理论分析和研究表明双旁路耦合电弧可以促进熔滴过渡并可显著降低喷射过渡的临界电流。展开更多
文摘The joining of Mg alloy to steel was realized by metal inert-gas arc welding, and the weld thermal cycle characteristics and Mg-steel joints were investigated. The results show that the temperature distribution in the joints is uneven. Mg alloy welds present a fine equiaxed grain structure. There exists a transition layer consisting mainly of AlFe, AlFe3 and Mg（Fe, Al）2O4 phases at Mg/steel interface, and it is the weakest link in Mg？steel joints. The welding heat input and weld Al content have the significant effect on the joint strength. The joint strength increases with increasing the heat input from 1680 J/cm to 2093 J/cm, due to promoting Mg/steel interface reaction. When weld Al content is increased to 6.20%, the joint strength reaches 192 MPa, 80% of Mg alloy base metal strength. It is favorable to select the suitable welding heat input and weld Al content for improving joint strength.
基金This research was supported in part by the SEGi University Sdn Bhd(Grant Number:SEGiIRF/2018-10/FoEBE-17/80)and in kind contribution of University of Malaya.
文摘Zincalume steel(G550)is commonly used in various construction fields because of its high corrosion resistance and good mechanical properties.In recent years,a number of steel companies have massively produced zincalume steel(G550)with large volumes of waste.For the reduction of massive industrial wastes,the zincalume steel(G550)was welded in the lap joint configuration using different welding parameters in the metal inert gas(MIG)welding and laser beam welding(LBW)process in this study.The MIG welding and LBW are more welcomed welding methods due to their high efficiency and low cost.However,they are different as the LBW offers welding speed three to five times faster than MIG welding,while LBW’s heat transfer to workpieces is much less than MIG welding,which can avoid some distortions.The microstructure of zincalume steel(G550)was investigated using scanning electron microscopy(SEM)and the microstructure characterizations of welded specimens were analyzed.The experiment found the columnar dendrites extended under the heat flow direction during the MIG welding and LBW process.Thus,the columnar grains were formed in between the equiaxed zone and fusion zone(FZ)at high heat input and slow cooling rate.Moreover,the grain size of FZ was comparatively smaller than heat affected zone(HAZ)and base metal(BM).
文摘Gas metal arc welding(GMAW)is also referred as the metal inert gas(MIG)welding which is a process of welding done by the formation of an electric arc between the consumable wire electrode and the workpiece.Through the welding process,a continuous flow of inert gas is supplied,and it avoids the weld being subjected to react with atmospheric air.The process can be automatic or semi-automatic where the main input parameters like current and the voltage can be direct and constant,respectively.Not only the current and voltage the welding quality depends on some more input parameters such as arc gap,velocity,and temperature.In this paper,we explain about a setup which is capable of real-time monitoring of input parameters mentioned above and selecting the best MIG welding parameters for the mild steel.The setup is composed of several sensors and microcontrollers for the collection and the measurement of the input parameters.The samples were categorized according to the federate and the voltage adjustment of the selected welding machine.Then the final objective was to identify the samples of the weld with different parameter changes which are monitored through the system.For the analysis,the samples were subjected to tensile and hardness tests,and microstructure tests to find the dependence of the input parameters which effect for the weld quality.Finally,the experimental results verified the effectiveness of the system for the selection of the quality weld.
文摘实现铝钢良好连接的关键是有效控制焊接热输入,尽量降低中间层铝铁金属间化合物的厚度,一般认为中间层金属间化合物厚度小于10μm时铝钢接头质量良好。提出旁路耦合电弧熔钎焊方法,通过调节旁路电弧电流的大小来控制焊接热输入。在优化控制系统和工艺参数的基础上采用脉冲旁路耦合电弧焊方法将铝镁合金ER5356堆焊到304不锈钢板上,获得结合良好的焊缝。对焊接接头进行扫描电镜(Scanning electron microscope,SEM)、能量色散光谱仪(Energy dispersive spectrometry,EDS)分析,结果表明:铝与不锈钢焊接接头中间层金属间化合物平均厚度约为8μm,小于10μm的临界厚度;脉冲旁路耦合电弧焊方法能够实现铝钢的连接,是一种新型低成本低热输入电弧焊方法。
文摘提出双旁路耦合电弧熔化极惰性气体保护(Dual bypass metal inert-gas,DB-MIG)电弧焊方法并建立试验系统。该方法以传统熔化极惰性气体保护焊接电弧为主弧,引入两路对称的电流可控的非熔化极旁路电弧并与主弧形成耦合电弧进行焊接。由于旁路电弧的分流作用,在保持较高焊丝熔化电流的同时可有效降低母材输入电流,并且旁路电弧力的作用对熔滴过渡也有显著的影响。设计专用的窄带滤光系统,实现无激光背光的焊接熔滴过渡行为的高速摄像,获得不同旁路电流参数条件下的铝合金DB-MIG焊熔滴过渡的高速摄影图像并进行分析。试验结果表明总电流恒定的情况下,熔滴过渡形态随旁路电弧电流参数改变而改变。对DB-MIG焊条件下作用于熔滴上的电弧力的分布进行理论分析,解释试验现象,理论分析和研究表明双旁路耦合电弧可以促进熔滴过渡并可显著降低喷射过渡的临界电流。
