August 9, 2022, a video of a large truck driving on the highway has sparked widespread concern among netizens, because the truck pulled a huge ring, accounting for four lanes. It is reported that this is the Guinness World Record for the largest overall ring rolled steel "world's first ring", with a diameter of 15.673 meters, being shipped from Jinan to the port of Weifang, Shandong port terminal.
Transport it special vehicles have a total of 106 wheels, including 10 tractor-trailer, the rear of the flat car 96, the highway exclusive 4 lanes. The flatbed can control the steering angle of different wheels and the overall height of the flatbed through a separate steering system. This forging ring is a fourth-generation nuclear power unit support ring, manufactured by Shandong Elite Energy Equipment Co., Ltd. Nearly 50 meters of the circumference of the whole body smooth and flat, one piece of molding, without a weld in the middle, can carry the weight of the nuclear power unit reactor vessel 7,000 tons, equivalent to the weight of the top 100 moving trains running. After installation in place for 60 years without replacement, representing the highest technical level of nuclear power forgings.
The manufacturing process of this large ring is as follows.
① First, metal billets of smaller dimensions are used as base elements, stacked layer by layer, placed in a vacuum environment, and sealed and welded.
② Heating to high temperatures and then repeated rotary rolling to completely bond the interface between the layers.
③ Stretching the rings as they are rotated and rolled, to a diameter of more than 10 meters.
④ Quenching to improve the rigidity, hardness, wear resistance, fatigue strength, and toughness of the rings.
⑤ Machining of the performance may also be required.
So, is it possible for this big ring to be manufactured by 3D printing technology in the future? China 3D printing network think can 2021, the national additive manufacturing innovation center, Xi'an Jiaotong University Lu Bingheng academician team using arc fusion wire increase and decrease material integration manufacturing technology, manufacturing completed 10m level high strength aluminum alloy heavy launch vehicle connection ring sample, in the overall manufacturing process stability, precision control and deformation and stress regulation, etc. are to achieve a major technical breakthrough.
The base of the ring can be rotated, and the print head uses electric arc as the heat source to melt the metal wire material, and under the control of the program, the metal ring is gradually formed by line - surface - body according to the 3D digital model, and the surface reduction machining is carried out at the same time during the printing process. This prototype weighs about 1t, and the innovative use of multi-filament collaborative process equipment has greatly simplified the manufacturing process, significantly reduced the cost, and shortened the manufacturing cycle to 1 month.