Research On 3D Printing Technology Of Multiway Pipe Joint In High Rise Building

Multiway pipe joint is widely used in high rise buildings,bridges,large offshore platforms and other engineering structures,for these complex multiway pipe joints,the current forming method is the whole casting,and the tubular part with large thick wall is easy to produce porosity,shrinks and other defects,it is hard to meet the requirements of multiway joint manufacturing,so there is an urgent need to develop new methods to obtain high performance multi joint.First of all,the influence of wire feeding speed and welding speed on the forming size of single channel multi layer weld is studied in the 3D printing process,and the uniformity of the packing size and the surface forming quality were analyzed.When the wire feeding speed is between 1.8m/min~5.2m/min and the welding speed is between0.2m/min~0.6m/min,the accumulation of morphology is good,and there is no downward flow phenomenon.In the welding current 120 A,arc voltage 20.1V,wire feeding speed of4.2m/min,welding speed of 0.5m/min,the pile height,the width change the least and the dimension uniformity is the best.The mathematical model of the profile of the weld is established,and the cosine of the contour of the multi layer weld is the highest.Then,according to the 3D model of multiway pipe joint,Comprehensive analysis of multiple pipe joint between four kinds of space curve,and the four types are fitted with intersecting line fitting,equal thickness plane slice algorithm and surfacing path simulation.According to the accuracy of the simulation path to make the rapid prototyping of the arc welding material of each space curve pipe joint,Analyze the dimensional error of each pipe joint.Finally,the 3D printing of multiway pipe joint is realized,and and the size of the print accuracy within the expected range.Finally,the mechanical properties and microstructures of the multiway pipe joint were tested,The microstructure was obtained by experiments to be a lot of fine anduniform ferrite and a small amount of pearlite.The average tensile strength is 560 MPa,higher than 12% of the standard value;The average yield strength is 420 MPa,higher than 45.8% of the standard value;The average elongation reached 27.65%,higher than the standard value of 25.7%;The average impact absorption of the measured value of147 J,and the impact of each sample are more than 120 J,higher than the standard value of more than 145%.At the same time,the fracture surface of the specimen was scanned,and it was found that the fracture was dendritic toughness fracture,The experimental data show that the microstructures and mechanical properties of the multiway pipe joint structure made up of the rapid manufacturing of arc material is in accordance with the requirements of construction steel.