The Investigation of Pipe Ends Formation under Reduction Mill Rolling

2018 ◽  
Vol 284 ◽  
pp. 557-562
Author(s):  
Dmitry A. Pavlov ◽  
Aleksandr Bogatov ◽  
E.A. Pavlova
Keyword(s):  
Experimental Study ◽  
Wall Thickness ◽  
Metal Flow ◽  
Thickness Variation ◽  
Oil Well ◽  
Transverse Wall ◽  
Reduction Procedure ◽  
Reduction Mill ◽  
Wall Thickness Variation

The paper presents the results of the experimental study of the longitudinal and transverse wall thickness variation at the ends of a oil-well tubing during reduction procedure. It is established that the greatest "contribution" to wall thickness data spread is made by the pipe facets, which is caused by the influence of the reduction regimes and the rolls calibration due to the metal flow into the tapers of groove. In the course of work, recommendations were also made that, in order to reduce the wall thickness variation of pipes, it is necessary to develop the calibration ensuring the decreasing of the intensity of metal flow into the tapers of groove, as well as decrease the reduction at the mill stands, and increase the coefficient of kinematic tension between the stands of the stretch-reducing mill.

scholarly journals A Design Approach of Porthole Die for Flow Balance in Extrusion of Complex Solid Aluminum Heatsink Profile with Large Variable Wall Thickness

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 553
Author(s):  
Tat-Tai Truong ◽  
Quang-Cherng Hsu ◽  
Van-Canh Tong ◽  
Jinn-Jong Sheu
Keyword(s):  
Wall Thickness ◽  
Metal Flow ◽  
Die Design ◽  
Design Approach ◽  
Thickness Variation ◽  
Extrusion Force ◽  
Bridge Structure ◽  
Flow Balance ◽  
Porthole Die ◽  
Wall Thickness Variation

In this study, porthole die used for extrusion of a solid heatsink profile with wall thickness variation ratio up to 15.3 was designed using finite element (FE) simulations. To improve the flow balance in the die, a design approach was introduced to find the appropriate die structure, which includes the porthole and pocket geometry correction, the bearing length adjustment, and the port bridge structure modification. Using the proposed die, the predicted velocity relative difference (VRD) and the maximum velocity difference (ΔV) of extrudate were significantly lower than those of an initial die, which was preliminarily designed based on general design experiences. The required extrusion force and the residual stress in the product were also reduced significantly. Then, the effects of the port bridge structure and welding chamber height on the behavior of the metal flow in the die were investigated. To verify the proposed die design, experimental extrusions were conducted on a 930-ton extruder. The experiment results showed that the extruded product fulfilled the requirements for dimensional tolerances. The design approach presented in this paper can be useful for practical implementation of die design when extruding similar solid heatsink profiles with large wall thickness variation.

Mechanics of Conventional Spinning

1963 ◽  
Vol 85 (4) ◽  
pp. 346-350 ◽  
Author(s):  
H. C. Sortais ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Wall Thickness ◽  
Pure Aluminum ◽  
Tangential Force ◽  
Deformation Energy ◽  
Thickness Variation ◽  
Force Component ◽  
Commercially Pure ◽  
Conventional Spinning ◽  
Wall Thickness Variation ◽  
Experimental Values

In conventional spinning of cones, the cone-wall thickness variation was studied using blanks of 1100-0 commercially pure aluminum sheet of 0.050-in. thickness. The results revealed that the radial stress induced in the unspun flange is the major cause of nonuniform wall thickness of spun cones. The theoretical tangential force component was derived by use of the deformation energy method. Qualitative agreement was found between the theoretical and the experimental values of tangential force component in the underspinning conditions.

Injection-Moulded Models of Major and Minor Arteries: The Variability of Model Wall Thickness Owing to Casting Technique

2005 ◽  
Vol 219 (5) ◽  
pp. 381-386 ◽  
Author(s):  
T O'Brien ◽  
L Morris ◽  
M O'Donnell ◽  
M Walsh ◽  
T McGloughlin
Keyword(s):  
Wall Thickness ◽  
Ccd Camera ◽  
Western Society ◽  
Experimental Investigations ◽  
Thickness Variation ◽  
Casting Technique ◽  
Radiological Images ◽  
Thickness Variability ◽  
Wall Thickness Variation ◽  
Integrated Technique

Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

Study on Three-Way Pipe’s Internal High Pressure Forming Simulation

2013 ◽  
Vol 589-590 ◽  
pp. 517-522
Author(s):  
Shi Gang Wang ◽  
Fu Sheng Gao ◽  
Feng Lan Cheng ◽  
Qiang Guo
Keyword(s):  
High Pressure ◽  
Wall Thickness ◽  
Three Dimensional ◽  
Thickness Variation ◽  
Forming Simulation ◽  
Finite Element Software ◽  
Plastic Processing ◽  
Wall Thickness Variation ◽  
Dimensional Shape ◽  
Pressure Parameter

Internal high pressure forming is a kind of the modern plastic processing technology. Using liquid as the pressure transmitting medium, explore the effect of internal high pressure parameter on the three passing pipe technique, internal high pressure forming technique is applied on the three-dimensional shape parts deformation. In this study, we simulate the three-way pipe process by finite element software, analyze the forming force influence to the tube forming quality and get the changeable regulation of the pipe wall thickness with conclusion of the wall thickness variation, which provides the reference data and guidance for the actual production of the three-way pipe.

Influence of Wall Thickness Fluctuation of Pierced Shell on Continuous Tube Rolling Process of Semi-Floating Mandrel Mill

2011 ◽  
Vol 189-193 ◽  
pp. 2382-2386
Author(s):  
Yuan De Yin ◽  
Sheng Zhi Li ◽  
Yong Lin Kang ◽  
Yang Hua Li ◽  
Gong Ming Long ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Rolling Force ◽  
Metal Flow ◽  
Equivalent Plastic Strain ◽  
Rolling Process ◽  
Steel Tube ◽  
Transverse Wall ◽  
Tube Rolling ◽  
Boiler Steel ◽  
Rolling Moment

In continuous tube rolling process, wall thickness reduction per stand will be changed due to wall thickness fluctuation of pierced shell caused by piercing process, which results in changes in metal flow conditions and affects force parameters, deformation parameters, especially transverse wall thickness precision of rolled hollow tube. In this paper, with the aid of commercial FE code MSC.SuperForm, the high pressure boiler steel tube continuous rolling process of a typical hollow tube specification 133.0×4.0mm are simulated based on 133 main pass sequence of 89mm 6-stand semi-floating mandrel mill, and force parameters, equivalent plastic strain, transverse wall thickness precision, outline dimension and real roundness of rolled hollow tube are analyzed and compared on the condition of two different wall thicknesses of pierced shell. Analysis results indicate that force parameters increase with wall thickness of pierced shell, maximal rolling force, rolling moment and mandrel axial force increase 10% or so in the first three stands when rolling pierced shell of wall thickness 11.5mm compared to that of wall thickness 10.5mm. When rolling pierced shell of wall thickness 10.5mm, there exist front and back tensions among the third, the fourth and the fifth stands and outline dimension and real roundness of rolled hollow tube is slightly better. However, transverse wall thickness of rolled hollow tube at the bottom of groove is pulled thin obviously.

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