Train Vehicles With The Wire Production Process Design, Preparation And Application, With A Large Aluminum Extrusions

Take 7020 large-type aluminum alloy plates for vehicle-train as object of weld, this thesisshows the design project that how to produce the welding wires, and designed melting-castplant and extrusion-drawing plant. On this basis, the Al-Mg-Cr-Mn-Ti aluminum alloy weldingwires were prepared by adding minor transition metal elements chromium, manganese andtitanium, advanced processing technology and micro-scraping surface treatment. Afterward,this kind of welding wire was used to weld 7020 large-type aluminum alloy plates for vehicle.With various experimental and testing methods, such as hardness testing, tensile mechanicalproperties testing, optical microscopy, transmission electron microscopy, the weld qualities ofAl-Mg-Cr-Mn-Ti alloy welding wires were evaluated, and investigated the relations of theproperties and microstructures of welded joints. The results as follow:1) The processing of vertical semi-continuous casting and extrusion is suitable to producethe aluminum alloy welding wires with good qualities and stable properties, it also suitable toproduce the important aluminum alloy weld structures in the vehicles and Al-Mg-Cr-Mn-Tiwelding wires.2) The Al-5.0Mg-0.1Cr-0.1Ti-0.1Mn aluminum welding wires were prepared by addingminor transition metal elements chromium, manganese and titanium, advanced processingtechnology and micro-scraping surface treatment.3) The processing parameters of welding wires are as follows: the homogeneous heattreatment of cast ingot is 470℃/24h; the temperature of extrusion is 420～460℃; extrusion ratiois 50～60. The deformation ratio of wiredrawing pass is 40～50%, the processing annealing is400～420℃/1h.4) Take 7020 large-type aluminum alloy plates for vehicle-train as object of weld, the weldqualities of Al-Mg-Cr-Mn-Ti alloy welding wires were evaluated, the tensile strength,elongation and strength coefficient of the weld joint is 261MPa, 4.8% and 0.76, respectively,reach the requires of DINEN288-4 Europe Standard.