Expansion of pipe blanks

2016 ◽  
Vol 36 (3) ◽  
pp. 239-243
Author(s):  
E. N. Sosenushkin ◽  
E. A. Yanovskaya ◽  
I. E. Smolovich ◽  
D. V. Khachatryan ◽  
V. Yu. Kinderov
Keyword(s):  
Author(s):  
S. R. Rakhmanov

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.


Author(s):  
Yi Han ◽  
Feng Liu ◽  
Xin Ran

In the production process of large-diameter seamless steel pipes, the blank heating quality before roll piercing has an important effect on whether subsequently conforming piping is produced. Obtaining accurate pipe blank heating temperature fields is the basis for establishing and optimizing a seamless pipe heating schedule. In this paper, the thermal process in a regenerative heating furnace was studied using fluent software, and the distribution laws of the flow field in the furnace and of the temperature field around the pipe blanks were obtained and verified experimentally. The heating furnace for pipe blanks was analyzed from multiple perspectives, including overall flow field, flow fields at different cross sections, and overall temperature field. It was found that the changeover process of the regenerative heating furnace caused the temperature in the upper part of the furnace to fluctuate. Under the pipe blanks, the gas flow was relatively thin, and the flow velocity was relatively low, facilitating the formation of a viscous turbulent layer and thereby inhibiting heat exchange around the pipe blanks. The mutual interference between the gas flow from burners and the return gas from the furnace tail flue led to different flow velocity directions at different positions, and such interference was relatively evident in the middle part of the furnace. A temperature “layering” phenomenon occurred between the upper and lower parts of the pipe blanks. The study in this paper has some significant usefulness for in-depth exploration of the characteristics of regenerative heating furnaces for steel pipes.


2017 ◽  
Vol 47 (5) ◽  
pp. 296-298 ◽  
Author(s):  
S. V. Samusev ◽  
G. P. Zhigulev ◽  
V. A. Fadeev
Keyword(s):  

Author(s):  
V. A. Saninsky ◽  
E. A. Fedyanov ◽  
E. N. Nesterenko

The article considers possible options for supplying coolant to the cutting and deforming teeth of multi-pronged firmware for processing deep holes. The advantages and disadvantages of each scheme are indicated. It is noted that when the lubricant-cooling liquid (coolant) is pushed through straight or screw slotted grooves made on the outer surface of the mandrel teeth, "damping pads" are created on the surface to be processed, which improve the mandrel process and reduce wear of the stitches for processing deep holes. For each of the schemes, a method for calculating the coolant flow rate is described, depending on the parameters of the slotted grooves for the coolant flow and the pressure of its supply. The ability to calculate the consumption of coolant through the cutting and deforming teeth of multi-toothed stitches allows you to correctly assign processing modes and, thereby, increase the technical and economic efficiency of mechanical processing of long pipe blanks.


2009 ◽  
Vol 39 (6) ◽  
pp. 501-505 ◽  
Author(s):  
O. A. Kobelev ◽  
A. V. Zinov’ev ◽  
M. A. Tsepin
Keyword(s):  

2010 ◽  
Vol 30 (5) ◽  
pp. 504-509
Author(s):  
A. N. Isaev ◽  
A. R. Lebedev ◽  
P. S. Arapov
Keyword(s):  

2016 ◽  
Vol 684 ◽  
pp. 143-151
Author(s):  
Sergey Sergeevich Yakovlev ◽  
Aleksey Alekseevich Perepelkin ◽  
Andrey Aleksandrovich Pasynkov

Provided here is a mathematical model of the operation of backward extrusion in the mode of short-time creeping of thick-walled pipe blanks made out of orthotropic material with cylindrical anisotropy of the mechanical properties. Carried out was theoretical research of the operation of isothermal axisymmetric backward extrusion of thick-walled pipe blanks made out of anisotropic materials by conic point-tool in the mode of short-time creeping. Established were regularities regarding the change of material flow kinematics, regarding the stressed and strained condition of the blank, regarding force modes and limit possibilities of deformation depending on the technological parameters, on friction conditions on the contact surfaces of the operating tools and of the blank, regarding the geometrical dimensions of the blank and of the manufactured part, and of the anisotropy of the mechanical properties of the blank material, that on the basis of the developed mathematical model of isothermal non-radial flow of anisotropic material under conditions of axisymmetric stressed and strained conditions in the mode of short-time creeping. Experimental operations were carried out for isothermal backward extrusion of thick-walled pipe blanks made out of АМг6 aluminum and ВТ6С titanium alloys. Comparing the results of theoretical and experimental data for force modes of the operation of isothermal backward extrusion of thick-walled pipe blanks points to their satisfactory similarity (difference not exceeding 5% - 10%).


2016 ◽  
Vol 36 (6) ◽  
pp. 472-475
Author(s):  
S. S. Yakovlev ◽  
V. I. Tregubov ◽  
E. V. Osipova

2010 ◽  
Vol 40 (12) ◽  
pp. 1037-1040
Author(s):  
S. R. Rakhmanov
Keyword(s):  

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