Pipe Billets Research Articles

Research of New Splitting Process of Pipe Billets from 2618A Aluminium Alloy Basing on Cross-Wedge Rolling

Abstract This paper are presented the results of theoretical and experimental research on splitting without waste of pipe billets from aluminium alloy realized basing on cross-wedge rolling method. The analyzed process is connected with rolling of a V-shape groove on a split billet circumference, and later with rotary bending causing material separation. In theoretical analysis, based on simulations by means of finite element method, basic models of metal cracking (brittle and ductile) were applied. During calculations, the following process parameters were changed: forming angle α, bending angle θ and reduction ratio ∆r. The achieved results allowed for a precise analysis of the splitting process within the scope of: state of strain, kinematics of flow, force parameters, state of stresses and type of cracking of the split material. On the basis of experimental research, the influence of the analyzed parameters on the surface of splitting was estimated and scope of parameters guaranteeing the assumed quality of the product was given. The comparison of theoretical and experimental results showed good conformity.

Виробництво партії трубних заготовок трекс-труб та виготовлення дослідно-промислової партії твельних труб зі сплаву Zr1Nb із вітчизняної сировини

Виробництво партії трубних заготовок трекс-труб та виготовлення дослідно-промислової партії твельних труб зі сплаву Zr1Nb із вітчизняної сировини

Autovacuum and its application for product cladding

On the basis of the discovered phenomenon of spontaneous pressure reduction in a hermetically sealed gap between two metallic surfaces during their heating, the E.O. Paton Electric Welding Institute developed a new brazing process i.e. autovacuum brazing, which produces brazed joints of several square meters area without the application of vacuum pumping. As the pressure reduces in the space between the metallic surfaces, they are cleaned from oxide films. The variation of pressure in the gap during heating is given and the mechanism of surface cleaning from oxide films is described. The autovacuum brazing is used in cladding high-pressure vessels, in the production of bimetal plates of unlimited thickness and bimetal pipe billets.