Forging Forming Technology And Optimization For Aluminum Alloy Axle Box Body

As important parts of bogies for the high-speed rail train,aluminum alloy axel box bodies are installed on the both ends of the axel,which transmit all of the load on spring including the dynamic load in plumb direction to axel.Also,they deliver the traction and breaking force to the framework.Deformation defects like sub-filling and coarse-grains occur easily because of the complex construction of the axel box body forging which cause the forge processes controlling difficultly.At present,domestic enterprises are not capable of producing the axel box bodies independently.To break the situation of depending on import as well as reducing the cost,the manufacturing process which can produce axel box body with good forming and high performance should be formulated.The research contents of this paper are proposing and optimizing forging forming process of aluminum alloy axle box body.To design the forming process and dies,the structure of axel box body and its difficulty during forming processes were analyzed and pre-judged.The billet forming process was determined to be two pieces forming together after the calculation according to empirical formula.Besides,the forging dies including the shape of mold joint and flash gutter for axel box body were designed.To deal with the complex structure of the bottom die,a scheme of double metal surfacing was proposed to design and manufacture it,which significantly decreases the cost of manufacturing.A finite element model for axel box body was constructed.Embracing the billet shape(three shapes),die preheating temperature(300°C、350°C and 400°C),pressing speed(5mm/s 、 1mm/s and shifting pressing)and friction condition(0.12 and 0.3),eight parameter combination schemes were designed for finite element simulation.After comprehensive comparison and analysis for the filling results,forming loads,effective strain distributions of billets and maximum principle stress distributions of dies,the optimal billet shape was obtained,the combination of die preheating temperature of 400°C,shifting pressing and the friction coefficient of 0.3 was determined to be optimized parameter combination.The forming processes of blocking was proposed based on the final shape of billet.Double billets drawing out in the first heat and single billet drawing out in the second heat was determined as the forming processes of blocking on the basis of empirical formula calculation.Embracing the initial forging temperature(350°C and 400°C)and anvil width ratio(0.5,0.6,0.7),six parameter combination schemes were designed for finite element simulation.The final forging temperature distributions,effective strain distributions and damage distributions were analyzed comparatively.As a result,the initial forging temperature was determined to be 350°C and the empirical value of anvil width ratio was proved to be reliable.Finally,the optimal parameter combination was applied in the actual production,and the results(forming load,filling results etc.)were close to the simulation results.To understand the property of the actual products,regular sampling the physical and chemical detections were conducted,its results showed that all detected parameters were above the standard requirements,which proved the reliability of simulation processes and process programs.