A. A. Bogatov

Finite-Element Modeling of Plate-Rolling

Results are presented from calculation of the geometry of the deformation zone and the kinematics of plate-rolling. The results were obtained using the program packages DEFORM-3D and Q-FORM. A comparative analysis is made of the data based on the length of the lag and advance zones and the character of the nonuniformity of the stress and strain states during the rolling of plates. The criterion chosen to characterize the nonuniformity of strain inside the deformation zone is the coefficient of variation S/Λav, where Λav is the average shear strain over the height of the plate and S is the standard deviation. The stress state was evaluated on the basis of the stress-state index σ/T. A mathematical model of the plate-rolling process was constructed with allowance for the range of steels rolled on the 5000 mill at the Magnitogorsk Metallurgical Combine and the technological capabilities of the mills equipment.

Use of the Lining Method to Restore the Service Characteristics of Pump-Compressor Tubing that Has Exhausted its Original Service Life

Preventing the premature wear of pump-compressor tubing (PCT) is an important problem in the Russian oil industry. This wear is caused mainly by different types of corrosion, and a new technology has been proposed to recondition damaged tubes. The technology involves lining damaged PCT with an internal thin-walled pipe made of corrosion-resistant steel, and it makes it possible to obtain composite tubes with excellent service properties. An experimental batch of lined tubes was tested under field conditions, with the results showing that the lining technology is a highly efficient means of increasing the service life of PCT.

Corrosion-resistant lined pump and compressor pipe

In pipe production, it is important to extend the working life of pump and compressor pipe for oil extraction. The use of lined pipe is an effective means of corrosion protection for pump and compressor pipe. However, experience in the production and operation of such pipe indicates that certain processes must be improved. New approaches to the production of lined pipe are proposed and tested in operating conditions.

Rolling hot-deformed pipe on a stub mandrel

A new method of rolling hot-deformed pipe on an automatic tandem mill consisting of two mills for longitudinal pipe rolling on a stub mandrel is proposed. In this method, the rough tube becomes oval immediately ahead of the rollers in the longitudinal-rolling mills. That ensures uniform filling of the groove and more uniform wall thickness of the pipe. The use of an oval rough tube increases the reduction on the first longitudinal-rolling mill from an elongation ratio of 1.5 to 2 and correspondingly decreases the reduction in the piercing mill. As a result, there is less risk of rolling skin on the outer surface of the pipe.

Crack Resistance of High-Strength Steel and Breakage of a Gas Pipeline

The available methods for identifying the type of failure of a 15–20 MPa gas pipeline used to evaluate the crack resistance of X90, X100, and Х110 high-strength steels cannot reliably predict the arrest of a main crack over the length of two or three pipes. Ductile fracture mechanics is used to determine the length of the plastic zone, the stress state, rate and degree of strain, and damage of the metal at the front of a growing macrocrack. A new fracture criterion based on plasticity diagram is proposed. The new approach to the evaluation of the crack resistance of steel reduces the growth rate of the main crack to less than the decompression rate of a gas pipeline after breakage and arrest of the main crack.

Intensification of Tube Plugging Based on Simulation Results

A new tube plugging process is described and studied on a lengthwise rolling mill installed on PRP-140 of the Sinara Pipe Plant. The deformation of a shell on a plug in a lengthwise rolling mill is studied using the finite-element method. The behavior of the dimensionless parameters characterizing the deformation of the metal in the groove tapers with variation in the elongation ratio of the shell is established. The effect of the ovality and kinematic tension of the shell on its deformation during plugging is analyzed through computer-aided simulation. It is established that applying kinematic tension and preovalization to the shell increases the elongation ratio by 37%, decreases the variation in wall thickness, and extends the range of tube grades produced with an automatic tube rolling mill.

Internal-diameter precision in the expansion of hot-rolled pipe

There is considerable demand for steel pipe at present in the construction industry. The most important characteristics of such pipe are dimensional precision, surface quality, high strength, and high performance. The precision of the pipe’s inner channel is of particular interest, since it determines the operational reliability and economic efficiency of the pipe. An effective method of increasing the precision is expansion of the pipe on a mandrel. The pipe precision may be investigated by means of finite-element modeling using computer software. That permits the investigation of contact-free expansion at the input and output of the deformation region, the nonuniformity of the deformation, and the increase in precision. The determination of these characteristics is fundamental to the development of optimal deformation conditions and tool design, so as to obtain pipe with a very precise internal diameter.

Shaping of metal in upsetting the ends of a pipe

The upsetting of the ends of a pipe on an SMS Meer hydraulic press is investigated by computer simulation. The shaping of the metal is studied by the finite-element method, and the most probable points of defect formation are determined: seams at the end of the pipe; and incomplete filling of the groove at the inner surface of the tool near the conical section of the matrix and close to the end. Technical recommendations regarding the reduction of waste facilitate the introduction of upsetting of the ends of PN 73 × 9.2 mm drill pipe in accordance with State Standard GOST R 50278-92 in a single pass.

New Engineering Solutions in the Production of Laminated Composite Pipes for the Oil Industry

The oil industry of Russia currently needs innovative development projects intended for a radical improvement of the performance of material resources and a decrease of their consumption. One of the most promising trends in corrosion protection is the production and use of pipes made of laminated composite materials. There are several principal ways of producing them by metal forming processes. World practice shows that lining technology is reasonable for oil well tubing. Lining consists of simultaneous expansion of pipes made of dissimilar materials, which possess different properties. A pipe of the kind manages to combine high corrosion resistance and mechanical strength, and this makes its service life more than four times higher than that of pipes made by conventional methods. However, previous foreign experience of manufacturing and using these pipes prompts the necessity of improving some pipe-making processes. This paper discusses new engineering solutions in the production of lined pipes, as well as in situ testing results.

Modernisation of the Method of Rolling of Hot-Rolled Tubes

A new method of hot-rolled pipes rolling on the automatic mill “tandem” is suggested. It consists of two rolling stands. This method allows one to achieve the rough pipe preovalisation before reaching the automatic mill. The rough pipe preovalisation provides even groove filling and the decrease of pipe wall thickness variation. Rough pipe preovalisation will allow us to increase the elongation ratio from 1.5 to 2.0 on the lengthwise rolling stand № 1 and to decrease the elongation ratio on the piercing mill. Therefore the chance of rolling skin formation on the external surface of pipe is decreased. The way to reduce the probability of the formation of a “guide mark” defect due to the kinematic tension during rolling on a stub mandrel with rough tube preovalisation is investigated. The influence of the kinematic tension factor on the pipe forming in the groove taper at a lengthwise rolling with rough tube preovalisation is explored.