Study On Localization For Aluminium Alloys Welding Wires Used On High Speed Train

At present our country’s high-speed aluminum alloy train body mainly used the automatic MIG welding. To realize automatic welding,welding wire must be accurate in size, have light and clean surface, and has certain stiffness. Domestic producted Al-alloy welding wires have serious quality problem,high-speed train aluminum alloy welding wire is still rely on imports.To relize the domestic of Al-alloy welding wires,this thesis aim at the5356,5183and5087aluminium alloy welding wire used on the high-speed train,using the semicontinuous casting and extrusion method to do the industrial trial production in Zhejiang Dong qing hi-tech welding wires CO.,LTD. We analysis the structure property tracking its production process,give freeback to the production site to adjust the productive technology,and produce qualified5356,5183and5087aluminium alloy welding wire. The main results turn to be as follows:(1) Developed melting and casting process of5XXX serials aluminium alloy welding wires,casting at730～740℃with the rate of110～120mm/min. The ingots casted by this process have fine grain, smaller and uniform distributed crystalline phases.But big block crystalline phases including Ti and Cr will occur in the ingots when the AlTiB silk thread added to refine the grain was added at relatively low temperatures,and it is hard to break during the follow-up processing.(2) Developed extruding and drawing process of5XXX serials aluminium alloy welding wires.Through the following process,ingots of5356,5183and5087alloy after homogenized could be prepared to qualified bright welding wire:extruded into12mm diameter work blanks at390℃to410℃with the extrusion ratio of59.the12mm diameter work blanks were drawing to2.76mm diameter in several times with reheat at390℃to400℃,drawing to finished product specifications in the bright-drawing productine line.(3) The composition of ER5356, ER5183and ER5087welding wire, produced by semi-continuously casting and extrusion method, can be controlled in the range of which the international standard demanded. The productes also have smaller and uniform distribution constituents and mechanical properties can reach the values reported by Japanese researchers and even better in elongation.(4) Revealing the evolvement rule of constituents of ER5356, ER5183and ER5087alloys in ingots, during the process of homogenization and plastic processing.