Seamless Steel Pipe Research Articles

Study on the preparation of the ceramic composite-lined steel pipe with the SHS reaction system of Al-Fe2O3-Cr2O3

Abstract The Al 2 O 3 -Fe-Cr composite was prepared and lined on the inner surface of the seamless steel pipe with the gravitational separation SHS method by using Al, Fe 2 O 3 and Cr 2 O 3 powders as the raw materials for improving the properties of the Al 2 O 3 -Fe-Cr composite-lined steel pipe. The effect of the amount of Cr 2 O 3 addition on the preparation process in the SHS reaction system of Al-Fe 2 O 3 -Cr 2 O 3 was discussed, and the micro-structure and properties of the Al 2 O 3 -Fe-Cr composite were observed and investigated. The results showed that a transition structure was formed in the SHS, which could improve the bonding quality of the composite-lined steel pipe; with the addition of Cr 2 O 3 , the Fe-Cr alloy formed and could improve the anti-corrosion ability of the Al 2 O 3 -Fe-Cr composite; the SHS speed decreased and the thickness and hardness of the Al 2 O 3 -Fe-Cr composite increased with the increase of the Cr 2 O 3 addition, and then the abrasion resistance was improved.

Evaluation of Microstructure and Mechanical Properties of Seamless Steel Pipes API 5L Type Obtained by Different Processes of Heat Treatments

This research presents the influence of manufacturing processes and heat treatments on the resulting microstructures and mechanical properties of an API 5L PSL2 seamless steel pipe. Three different conditions are considered - as rolled, normalized and quenched and tempered - to obtain the grades X42R, X42N and X70Q, respectively. Scanning electron microscopy techniques was used to characterize the resultant microstructures. Tensile, hardness, impact, fracture toughness (J integral) and fatigue crack growth tests (da/dN x ΔK) were used to study the materials mechanical behavior. The results show the possibility of achieving API grades for a seamless pipeline steel, through suitable heat treatments. The microstructural modifications and mechanical properties changes observed showed a remarkable structure-properties relationship of the steel, and attempt to a proper selection as required by the structural design. The quenching and tempering process increased tensile mechanical properties and fracture toughness, but combined to a significant decrease in fatigue crack growth resistance.

Characterization of the Welded-Joint of High-Strength High-Toughness Seamless Steel Pipe under High-Cycle Fatigue Condition

The welded joint of a S890QL grade steel pipes containing 1.2% Ni have been prepared to characterize the use performance under high cycle fatigue test. It has been found that the fatigue strength of the welded joint is 290MPa with a fatigue life of more than 10 million cycles, and the obtained Basquin equation is σa=488*(2N)-0.02758 . It is found that the steel exhibits the whole bainite microstructure when the cooling rate is less than 1°C/s. The welded joint is divided into the weld zone, the coarse grain zone, the fine grain zone, the softening zone and the matrix. The fine grain characteristic in the welded area determines the good anti fatigue performance of the investigated steel.

Effect of tangential velocity on erosion of ASTM A-106 Grade B steel pipe under turbulent swirling impinging jet

Swirling jet flows are of interest in many industrial processes such as those involving combustion, separation, propulsion, cooling, dredging, excavation, cleaning, etc. In recent years some researches have dealt with erosion mechanisms behaviour onto different materials, for instance concrete, coatings, ceramics, composites, diamond like carbide films, metallic alloys, etc. However the erosive wear behaviour of metallic materials subjected to swirling impinging jets has not been studied. An erosion tester was designed and built to erode the metallic specimens at swirling and non-swirling conditions. Erosion tests were conducted on seamless carbon steel pipe ASTM A-106 Grade B coupons as target material. Solid particle erosion tests were carried out with 50µm of aluminium oxide particles at a velocity of 17ms−1 at two regimes, non-swirling jets and weakly swirling jets (2000–6000min−1). The impinging angle was 30°, 45°, 60° and 90° in the near-field. Resulting that the dominant erosive wear mechanism at all conditions tested was plastic deformation. Also, the maximum mass loss values were obtained at non-swirling regime and low angles of incidence. Finally, the erosion rate decreased when the swirl number was rised. Hence, the turbulent swirling impingement jet was less severe than turbulent non-swirling impingement jet in the erosion of the A-106 Grade B material.

Experimental and numerical study of steel pipe with part-wall defect reinforced with fibre glass sleeve

The paper presents numerical and experimental burst pressure evaluation of the gas seamless hot-rolled steel pipe. The main goal was to estimate mechanical toughness of pipe wrapped with composite sleeve and verify selected sleeve thickness. The authors used a nonlinear explicit FE code with constitutive models which allows for steel and composite structure failure modelling. Thanks to the achieved numerical and analytical results it was possible to perform the comparison with data received from a capacity test and good correlation between the results were obtained. Additionally, the conducted analyses revealed that local reduction of pipe wall thickness from 6 mm to 2.4 mm due to corrosion defect can reduce high pressure resistance by about 40%. Finally, pipe repaired by a fibre glass sleeve with epoxy resin with 6 mm thickness turned out more resistant than an original steel pipe considering burst pressure.

Helical comb magnetostrictive patch transducers for inspecting spiral welded pipes using flexural guided waves

A wavefront analysis indicates that a flexural wave propagates at a helix angle with respect to the pipe axis. The expression for calculation of the helix angle for each flexural mode is given, and the helix angle dispersion curves for flexural modes are calculated. According to the new understanding of flexural guided waves, a helical comb magnetostrictive patch transducer (HCMPT) is proposed for selectively exciting a single predominant flexural torsional guided wave in a pipe and inspecting spiral welded pipes using flexural waves. A HCMPT contains a pre-magnetized magnetostrictive patch that is helically coupled with the outer surface of a pipe, and a novel compound comb coil that is wrapped around the helical magnetostrictive patch. The proposed wideband HCMPT possesses the direction control ability. A verification experiment indicates that flexural torsional mode T(3,1) at center frequency f=64kHz is effectively actuated by a HCMPT with 13-degree helix angle. Flexural torsional modes T(N,1) with circumferential order N equals 1–5 are selected to inspect a seamless steel pipe, artificial defects are effectively detected by the proposed HCMPT. A 20-degree HCMPT is adopted to inspect a spiral welded pipe, an artificial notch with cross section loss CSL=2.7% is effectively detected by using flexural waves.

Finite element analysis of cyclically-loaded steel pipes during deep water reeling installation

Thick-walled steel pipes during their installation in deep water are subjected to combined loading of external pressure and bending, which may trigger structural instability due to excessive pipe ovalization. In the case of reeling installation method, prior to deep-water installation the pipe is subjected to cold forming associated with strong cyclic bending on the reel, resulting in the development of initial ovalitization and residual stresses, which may affect the pipe structural performance. Using advanced material models and finite element tools, the present study examines the effect of cyclic loading due to reeling on the mechanical behavior of thick-walled seamless steel pipes. In particular, it examines the effects of reeling on cross-sectional ovalization and the corresponding material anisotropy and, most importantly, on pipe resistance against external pressure and pressurized bending. The results show that cyclic bending due to the reeling process induces significant anisotropy and ovalization on the pipe. It is also shown that the mechanical resistance of reeled pipes is lower than the resistance of non-reeled pipes, mainly because of the resulting cross-sectional ovalization at the end of reeling process.

Study on anti-freezing functional design of phase change and temperature control composite bridge decks

The bridge decks during the winter time usually present a poor performance of freeze resistance. Using the phase change energy-storing technology and functionally-graded materials design method, we designed and prepared a composite anti-freezing bridge deck structure. Compared with conventional bridge decks, the anti-freezing bridge deck has a phase change functional layer which consisted of high strength seamless steel pipes paved parallelly at a certain interval, and the liquid phase change materials are filled in the pipes. Through theoretical study and laboratory model tests, it has been proven that the large amount of heat given off by the new bridge deck structure during the liquid-solid phase change process has a good effect on melting ice and snow. On the other hand, in order to research the influence the heat has on the mechanical properties of the bridge deck, a simulation analysis has processed by the finite element software. The results show that: the seamless steel pipe buried in the transformation function layer has an effect on the reinforcement of the deck structure, which also greatly enhances the overall strength and stiffness. The bottom layer tensile stress and vertical displacement of the phase change functional layer are about 74% and 92% respectively of those without one. Meanwhile, the average values of tensile stress and the vertical displacement of the former are less than those of the latter. Finally, an optimal layout scheme was found through the comparative analysis of influence of pipe spacing and depth while the bridge deck was experiencing stress.

Numerical Study on Weld Joints of Steel Longitudinal Welded Piles during Pile Driving Process

Longitudinally welded steel pipe piles are not as commonly used as seamless steel pipe piles in offshore platform. Although longitudinally welded steel pipe piles are considerably cheaper than seamless steel pipe piles, yet many feared that longitudinally welded steel pipe piles are prone to fail because of non-uniformity in the heat affected zone (HAZ), especially when receiving impact loads during the installation process. In this paper, a finite element model is developed to study the deformation and failure of the longitudinal welded piles. Two modelling cases are performed: single and double piles, with two different failure parameters: maximum stress and maximum plastic displacement.

Thermo-mechanical fatigue approach to predict tooling life in high temperature metal forming processes

In high temperature metal forming processes, strong mechanical and thermal cyclic loads coexist in the formed material and in the tooling. Such a phenomenon has a negative influence in the tool life cycle. The thermal and mechanical ranges lead to the appearance of cracks on the tool surface because of thermo-mechanical fatigue damage (TMF). The objective of this paper is to present a simplified cumulative thermo-mechanical fatigue model which has been developed in order to study the most critical areas in the forming tools according to the predicted number of cycles up to crack appearance considering multi-axial fatigue and oxidation. This model is based on assumptions of a general cumulative TMF model proposed by Neu and Sehitoglu; and critical plane approaches by Smith, Watson and Topper, and Fatemi and Socie. In general, cumulative TMF approaches three agents are considered: multiaxial-fatigue, oxidation and creep. The developed model has been applied to a specific manufacturing process of seamless steel pipes which includes three basic forming steps: backward extrusion, perforation and Pilger rolling mill. This process transforms a blank, or ingot, into a final seamless steel pipe with specific dimensions and characteristics depending on market requirements. These studies have been carried out in order to improve the tool life. To this end, the forming process has been reproduced by means of coupled thermo-mechanical FE simulations using the ABAQUS/Explicit solver. Moreover, a post-processing subroutine has been incorporated which enables to predict the number of cycles until crack appearance (tool life) according to both the general model of Neu and Sehitoglu, and the specific model developed. Good correlations between predicted and actually observed damage areas have been reached in both cases. The advantage of the hereafter proposed TMF model is that, it takes the most convenient features of general TMF models and it is particularized to a reduced input TMF model in order to analyze high temperature metal forming processes.

Sensitivity analysis of the Expansion Process for Alloy UNS N08028

Due to the good mechanical properties of forged parts, the forging process plays a decisive role in the manufacturing of seamless stainless steel pipes for oil country tubular goods (OCTG) lines. Tough competition between manufacturers gives them plenty of incentive to make their processes in raw material and energy usage more and more efficient. In this context the expansion process is one of the critical production steps in the manufacturing of seamless stainless steel pipes. This work presents a sensitivity analysis of a finite element method (FEM) for the simulation of the expansion of the alloy UNS N08028. The input parameters ram speed, tool angle, initial ID and final ID of the billet as well as temperature were used to describe responses like tool wear and material loss. With the aim to minimize the tool wear and to reduce the material waste, a study of influence of the input parameters on the mentioned responses were performed. This development is supported by experimental work in order to validate the simulation model. The sector demand for new materials with specific properties and the cost-intensive experimental trials justifies the use of such simulation tools and opens great opportunities for the industry.

Performance and confining mechanism of grouted deformed pipe splice under tensile load

In this study, a new type of grout-filled coupling sleeve was presented. The sleeve was fabricated with a standard seamless steel pipe through cold rolling techniques and characterized by its unique processing method and configuration. Based on this sleeve, 11 coupler specimens of four categories with embedment length from 7 to 7.5 times bar diameter were prepared and tested under tensile load to study the failure modes, structural performance, and confining mechanism of the splice. Test results clearly indicated that this kind of splice provided satisfactory behavior of which the ultimate tensile strength all exceeded the required loading capacity specified in ACI318 and JGJ107. Furthermore, it was found that the inner cavity structure of grouted sleeve had great influence on the confinement, which consequently affected the bond performance of spliced bar. Based on the experimental results, equations were derived to calculate the confining interface pressures and the bond resistance of the spliced bar, and the calculated ultimate load showed a good agreement with the experimental value.

The Effect of Ultrasonic Peening on Service Life of the Butt-Welded High-Temperature Steel Pipes

Residual stresses introduced by manufacturing processes such as casting, forming, machining, and welding have harmful effects on the mechanical behavior of the structures. In addition to the residual stresses, weld toe stress concentration can play a determining effect. There are several methods to improve the mechanical properties such as fatigue behavior of the welded structures. In this paper, the effects of ultrasonic peening on the fatigue life of the high-temperature seamless steel pipes, used in the petrochemical environment, have been investigated. These welded pipes are fatigued due to thermal and mechanical loads caused by the cycle of cooling, heating, and internal pressure fluctuations. Residual stress measurements, weld geometry estimation, electrochemical evaluations, and metallography investigations were done as supplementary examinations. Results showed that application of ultrasonic impact treatment has led to increased fatigue life, fatigue strength, and corrosion resistance of A106-B welded steel pipes in petrochemical corrosive environment.

Application of Concrete Filled Steel Tubular Supports in the Shaft Station

In order to solve the issues of large deformation and difficult to support in Lu Cun coal mine-270m level shaft station, the reasons of damage to the original roadway supporting conditions have been analyzed through the field investigations. A composite supporting scheme which depend mostly on concrete-filled steel tubular (CFST) supports, spray the anchor net and surrounding rock grouting reinforcement technology as a supplement was designed. The cross-section of the supports is circular. The main steel pipe is 20# seamless steel pipe with diameter of 194mm and wall thickness of 8mm. It is shows that the composite supports can effectively control the deformation of surrounding rock of roadway and maintain long-term stability.

Behaviour of Grout-Filled Splice under Monotonic and Cyclic Loads

Grout-filled mechanical splice system is one of the most important technologies for precast construction. However, due to the high cost of grouted sleeve in Chinese construction market, the implementation of this technology is hindered. In this study, a new type of grouted sleeve was developed with standard seamless steel pipe by cold rolling depression. Utilizing this sleeve, eight coupler specimens were prepared and tested under incremental tensile load and cyclic load. The results indicate that all the specimens provided satisfactory behaviour of which the ultimate tensile strength exceeded the required loading capacity specified in ACI318 and JGJ107. The inner cavity configuration of the grouted sleeve has great influence on the confining mechanism of the splice and on the strain distribution in the sleeve. Because the compressive strength of grout is greatly higher than its tensile strength, the slope of the load-strain response curve of the sleeve under tensile load is lower than it under compressive load.

A New Internal Detection Method for Fluid Transportation Pipeline Leak Based on Active Electrolocation

Pipeline leak internal inspection method is a key technology of safety assessment for industrial pipeline. Weakly electric fish can sense its surrounding environment by generating electric fields and detecting distortions through their active electrolocation system. In this paper, a new internal inspection leak method for fluid transportation pipeline, the active electrolocation internal inspection method, is proposed to pipe detection which is inspired by active electrolocation system of weakly electric fish. An experimental system for fluid transportation pipe leak detection based on active electrolocation has been constructed. To test the feasibility of this method and this experimental system's performance, the detecting property of this method with different working conditions for different material pipe, metallic and non-metallic pipes, were studied in this paper. And then, FFT (fast Fourier transformation) and joint time-frequency analysis was applied to analyze and process experimental data. FFT provides an available method to analyze the experimental results in the frequency domain at different point. Meanwhile, the joint time-frequency analysis method can achieve the observation any frequency component in the whole time domain. Finally, the positioning error and relative error of this method has been discussed and analyzed in this paper. In our study, experimental results show that leak spot in seamless steel pipe and PVC (polyvinyl chloride polymer) pipe with different working conditions can be effectively detected by the method. The internal inspection method for fluid transportation pipeline leak based on active electrolocation was validated by our study, which lays a foundation of a new online detection in pipe engineering field. A new internal inspection method for fluid transportation pipeline based on active electrolocation has been developed.

Modeling of Distributed Parameter Processes with Neural Networks

In this paper an original solution for the modeling of distributed parameter processes using neural networks is presented. The proposed method represents a particular alternative to a very accurate modeling-simulation method for this kind of processes, the method based on the matrix of partial derivatives of the state vector (Mpdx), associated with Taylor series. In order to compare the performances generated by the two methods, a distributed parameter thermal process associated to a rotary hearth furnace (R.H.F) from the technological flow of producing seamless steel pipes is considered. The main similarities and differences between the two methods are highlighted in the paper. The treated solution represents a premise for the usage of the neural networks in the automatic control of the distributed parameter processes domain.

Asymmetric buckling of offshore pipelines under combined tension, bending and external pressure

The seamless steel pipes inevitably incorporate various initial geometric imperfections introduced in the manufacturing process. The offshore pipelines close to the touch-down point in the sagbend have to withstand the combined actions of axial tension, bending and external pressure during deepwater installation. In this paper, a two-dimensional (2D) theoretical formulation is further developed to investigate the asymmetric buckling behaviour of offshore pipelines with arbitrary initial geometric imperfections under complicated loading conditions. In addition, numerical simulations based on a 3D finite-element model of the imperfect tube using the software ABAQUS are carried out. Close agreement between the results demonstrates the effectiveness and practicality of this theoretical method. The theoretical model is then employed to study the effects of some important influencing factors such as initial geometric imperfections represented by initial ovality and wall eccentricity, ovality orientation, material properties represented by effective yield stress and strain-hardening parameter, diameter-to-thickness ratio, axial tension, and load cases on the buckling behaviour of the imperfect tubes. Based on extensive parametric studies, some significant conclusions were drawn.

钢管管端内外径测量系统的设计与实现

To realize automatic non-contact measurement for the inside diameter,outside diameter and the out-of-round of a steel pipe end,a measurement system for inside and outside diameters of the steel pipe was designed.Two laser optical triangulation sensors were used to perform full scans of the inside and outside diameters as they rotated around the pipe ends.Then a fitting algorithm was taken to reduce errors brought by the misalignment between rotary axis and steel pipe axis.Moreover,the distance between measured cross section and pipe end was adjusted by motorized translation stages fixed on the sensor,the aligning height of pipe center was adjusted by a lifter and the measurable pipe diameter was controlled with a two-aim translation stage,so that the measurement of steel pipes with different specifications could be implemented by the non-contacted method.Experimental results indi-cate that the measurement accuracy of the system is less than 0.05mm;repeatability limit is less than or equal to 5μm.When 500points are sampled per pipe end,the measurement process lasts less than 25s.which can fully meet the requirements of seamless steel pipe production enterprises.With advantages of high precision,easy operation and rapid speed,the system has passed the off-line test in Tian Guan Yuan Tong pipe products Co.,Ltd.,Tianjin.

Extension of subloading surface model for accurate prediction of elastoplastic deformation behavior of metals with cyclic softening

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior of metals. However, the existing formulation of this model is limited to metals exhibiting only the cyclic hardening. In the present paper, the material functions prescribing the elastic-plastic transition are extended so as to describe the inverse and reloading behavior and the strain accumulation in cyclic loading more accurately for metals exhibiting not only the cyclic hardening but also the cyclic softening behavior. The experiments on the uniaxial cyclic loading of the seamless steel pipe P110 which exhibits the cyclic softening are performed for the mechanical ratcheting and the constant strain amplitudes. The simulations to the test data are performed by using the same set of material constants. Then, the validity of the extended model for the description of cyclic loading behavior of the seamless steel pipe is verified by comparisons with the test data.