为实现铝合金LD10焊接变形率小于0.8%的精密扩散焊,分别在480℃、505℃固相条件下施加60 m in、4.5 MPa恒定轴向压应力,535℃固-液相条件下施加60 m in、4.5 MPa恒定轴向压应力与60 m in、6 MPa^0线性递减轴向压应力。焊后用扫描电镜(S...为实现铝合金LD10焊接变形率小于0.8%的精密扩散焊,分别在480℃、505℃固相条件下施加60 m in、4.5 MPa恒定轴向压应力,535℃固-液相条件下施加60 m in、4.5 MPa恒定轴向压应力与60 m in、6 MPa^0线性递减轴向压应力。焊后用扫描电镜(SEM)观察了试件基体的组织形貌、接头焊合率;用X射线衍射分析仪(XRD)分析了焊接前、后试件的相组成;测量了焊后接头的抗拉强度。结果表明,535℃的固-液相线性递减轴向压应力扩散焊与480℃、505℃的固相恒定轴向压应力扩散焊相比,在保证了小变形率0.71%的同时,显著提高了接头焊合率和机械强度(σb=218 MPa)。同时焊前的轴向织构转变为焊后粗大等轴晶形式,强化相CuA l2以晶界和三晶夹角的沉积形式取代焊前的轴向条纹聚集形式。与535℃固-液相恒压扩散焊相比,可有效地避免失稳变形与热裂纹。展开更多
Magnetically impelled arc butt(MIAB) welding is a pressure welding process used for joining of pipes and tubes with an external magnetic field affecting arc rotation along the tube circumference. In this work, MIAB we...Magnetically impelled arc butt(MIAB) welding is a pressure welding process used for joining of pipes and tubes with an external magnetic field affecting arc rotation along the tube circumference. In this work, MIAB welding of low alloy steel(T11) tubes were carried out to study the microstructural changes occurring in thermo-mechanically affected zone(TMAZ). To qualify the process for the welding applications where pressure could be up to 300 bar, the MIAB welds are studied with variations of arc current and arc rotation time. It is found that TMAZ shows higher hardness than that in base metal and displays higher weld tensile strength and ductility due to bainitic transformation. The effect of arc current on the weld interface is also detailed and is found to be defect free at higher values of arc currents. The results reveal that MIAB welded samples exhibits good structural property correlation for high pressure applications with an added benefit of enhanced productivity at lower cost.The study will enable the use of MIAB welding for high pressure applications in power and defence sectors.展开更多
文摘为实现铝合金LD10焊接变形率小于0.8%的精密扩散焊,分别在480℃、505℃固相条件下施加60 m in、4.5 MPa恒定轴向压应力,535℃固-液相条件下施加60 m in、4.5 MPa恒定轴向压应力与60 m in、6 MPa^0线性递减轴向压应力。焊后用扫描电镜(SEM)观察了试件基体的组织形貌、接头焊合率;用X射线衍射分析仪(XRD)分析了焊接前、后试件的相组成;测量了焊后接头的抗拉强度。结果表明,535℃的固-液相线性递减轴向压应力扩散焊与480℃、505℃的固相恒定轴向压应力扩散焊相比,在保证了小变形率0.71%的同时,显著提高了接头焊合率和机械强度(σb=218 MPa)。同时焊前的轴向织构转变为焊后粗大等轴晶形式,强化相CuA l2以晶界和三晶夹角的沉积形式取代焊前的轴向条纹聚集形式。与535℃固-液相恒压扩散焊相比,可有效地避免失稳变形与热裂纹。
文摘Magnetically impelled arc butt(MIAB) welding is a pressure welding process used for joining of pipes and tubes with an external magnetic field affecting arc rotation along the tube circumference. In this work, MIAB welding of low alloy steel(T11) tubes were carried out to study the microstructural changes occurring in thermo-mechanically affected zone(TMAZ). To qualify the process for the welding applications where pressure could be up to 300 bar, the MIAB welds are studied with variations of arc current and arc rotation time. It is found that TMAZ shows higher hardness than that in base metal and displays higher weld tensile strength and ductility due to bainitic transformation. The effect of arc current on the weld interface is also detailed and is found to be defect free at higher values of arc currents. The results reveal that MIAB welded samples exhibits good structural property correlation for high pressure applications with an added benefit of enhanced productivity at lower cost.The study will enable the use of MIAB welding for high pressure applications in power and defence sectors.
