Key Technologies Of Bimetal Tube Expanded Forming And The Equipment Research

Piping as a safety,economical,reliable transportation,have been widely used in the transportation of petroleum,chemical etc.Bimetal tube is a new type pipe which is made of two different material.It is complex utlized the advantages of material characteristics.In this dissertation,the principle of bimetal tube expanded forming, the key technology of fabrication and application has been researched.Application the elastic-plastic theory,in accordance with the five state of combination,it has exported the theory calculation formulas of the relation expanding pressure to the residual contact pressure,it has used the equivalent yield stress to calculate the residual contact pressure,the formulas results are consistent with the FEA and the experiment results.This paper has presented the expanded forming theoretical handy conditions:σ_so＞σ_si.It has analyzed the geometric body factors of pipe diameter ratio k or K to influence of the bimetal performance.The study discovered that the extreme value of the expanded forming pressure,the pipe diameter ratio k or K influence the spacing of expanded forming pressure.It has developed the bimetal tube expanded forming machine and improve this machine,it has apply the gigid and the flexible drive construction,and at the same time improved the construction of axis,applied the six side construction,it has obtained the good application.It analysis the bimetal tube of the using characteristics at the high temperature,and it presented the mechanism of bimetal tube looseness.