Seamless Steel Pipe Research Articles

A Novel Neural Network Architecture Dedicated for LIBS Spectrum Analysis With Its Application to Steel Pipe Classification

Abstract As a non-destructive rapid composition analysis method, Laser-induced breakdown spectroscopy (LIBS) has received widespread attention in recent years. However, its application in the steel industry has not achieved an effective breakthrough in its detection accuracy due to the existence of matrix effect. This paper introduces a neural network model for LIBS spectral line analysis, which can automatically construct the features and analyze the correlation between them, and this model has been applied in the steel sample classification of seamless steel pipe with good results.

Effective strategies for improving quenched microstructure and mechanical properties of hot-rolled seamless steel pipes

The containing Ti-Mg-Ca-O composite particles were innovatively used to achieve microstructure refinement and properties improvement of hot-rolled seamless steel pipes, and compared with conventional steel (C# steel). The results show that the C# steel mainly consisted of parallel lath martensite after on-line quenching. Under the same rolling and heat treatment conditions, dominant Ti-Mg-Ca-O composite particles in modified steel (M# steel) were effective nucleation sites of acicular ferrite, dividing the prior austenite grains and refining microstructures. The strength values of the both steels were at the same level, however, the impact energy of M# steel was significantly higher than C# steel, increasing by 28%. This study provides an effective method for further microstructure refinement of hot-rolled seamless steel tubes.

Selection of internal design of crystallizer sleeves for continuous casting of 200 mm billets

The crystallizer is the most critical and most important functional unit of a continuous casting machine (hereinafter referred to as CCM). It is the main technological unit of the CCM, an assembly for removing heat during the solidification of the solidifying metal and the formation of the ingot. The main requirement for the crystallizer is to provide maximum heat removal from the solidifying steel to the cooling water, and to obtain a strong ingot shell with a good surface at the outlet of the crystallizer, which would not be destroyed by the heat of the liquid phase and the ferrostatic pressure. During the reconstruction of the CCM by the contractor company, drawings of crystallizers and crystallizer sleeves with a double‑cone internal geometry for casting 200 mm continuous cast billets were developed. The 200 mm continuous cast billet is a billet for the production of hot‑rolled seamless steel pipes. During the operation of the crystallizer sleeves with a double‑cone internal geometry, an accelerated wear of the protective coating in the lower part of the sleeve was noted, as well as an increased rejection of hot‑rolled pipes due to defects on the outer surface of the pipes. In order to identify the cause of the defect formation, complex metallographic studies of the outer surface of the pipes were carried out. As a result of the metallographic study, surface defects classified as steel mill scale on the outer surface of the pipes were identified. To minimize the “steel mill scale” defect and reduce the wear of the protective coating of the crystallizer sleeves, work was carried out to select the optimal conditions for the crystallization of the continuous cast billet: the use of crystallizer sleeves with a three‑cone internal geometry compared to a double‑cone was investigated; maintaining the temperature difference of the water at the inlet and outlet of the crystallizer within specified limits (ΔT) was tested. It was found that the use of a crystallizer sleeve with a three‑cone internal geometry for casting 200 mm billets and the stable behavior of the ΔT parameter made it possible to ensure the required quality of the surface of seamless pipes, reduce the wear of the protective coating of the crystallizer sleeves and increase the productivity of the CCM.

Improving anti-corrosion and mechanical properties of mild steel pipelines by using polyurea with nanoparticles

ASTM A106 B grade is used to manufacture seamless steel pipe, which can be used at high temperature, pressure, and hard environmental conditions for oil and gas supplies but suffers from corrosion. Polyurea is an organic coating that is resistant to moisture, UV light, and chemicals and has a high range of service temperatures. In this study, the effect of polyurea coating with the addition of copper nanoparticles was investigated for improvement of anti-corrosion and mechanical behavior in 3.5 % NaCl solution for A106 steel. Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) tests were performed to examine anticorrosion properties, Scanning Electron Microscopy (SEM) was used to examine quality coating, thickness, and distribution of copper nanoparticles. Wear, hardness, and tensile tests were performed to check mechanical properties. The corrosion rate decreases from 0.16264 mpy to 0.01376 mpy while coating resistance increases from 2.95 × 104 Ω cm2 to 2.474 × 105 Ω cm2. An increasing trend was observed during the tensile test for pure polyurea and pure polyurea with 2 % copper nanoparticles. i.e., 501 MPa and 536 MPa, respectively. Results showed pure polyurea and polyurea with copper nanoparticles on steel improve its anti-corrosion and mechanical properties significantly.

Improving the technology of producing seamless hot‑rolled pipes from stainless steel l80 type 13Cr in the tube rolling workshop

The production of seamless hot‑deformed pipes from martensitic stainless steel with a high chromium content, used under the constant influence of aggressive environments, involves overcoming a series of technological challenges. These challenges are due to the metal’s structural features, such as relatively low plasticity, a narrow temperature range for hot deformation, a tendency to defect formation during rolling, and more intense wear on the rolling tools. The article discusses the main stages of research work on mastering the technology of producing seamless hot‑rolled pipes from stainless steel grade L80 type 13Cr at OJSC “BSW – Management Company of Holding “BMC”. It presents the results and complexities of mastering the technology for producing seamless stainless steel pipes, analyzes the results aimed at reducing the cost of finished products by increasing the durability of piercing mandrels, the resistance of disc saws for cutting blanks, eliminating metal adhesion to the piercing mill’s Dishar discs, increasing the productivity of the rolling line and heat treatment process.

A New Type of Online Accelerated Cooling Equipment for Seamless Steel Pipe and Its Application Experiments

A New Type of Online Accelerated Cooling Equipment for Seamless Steel Pipe and Its Application Experiments

Technology Optimization Analysis of Three-Roll Rotary Piercing Process for Seamless Steel Pipe

Technology Optimization Analysis of Three-Roll Rotary Piercing Process for Seamless Steel Pipe

Bond Performance of Seamless Steel Pipe Grouting Sleeves under Large-Deformation Repeated Tension and Compression after High Temperature

Grouting sleeves are widely used in the field of assembled construction. The present study aims to investigate the reliability of grouting sleeves under large-deformation repeated tension and compression after high temperature, considering the influences of steel bar diameter, the cooling method, and the protective layer. Through experimentation on 28 test pieces, we analyzed the bonding performance of the test pieces at different high temperatures. The results indicate that within the temperature range of 20–800 °C, the bond performance of the test pieces declines by no more than 9.8%. However, upon reaching a temperature of 1000 °C, the bond performance of the test pieces decreases by over 33.7%, with the compressive strength of the grout material reduced to only 27.50% of that kept at 20 °C. Employing larger-diameter steel bars is advantageous for maintaining the bond performance of the test pieces. Natural cooling shows relatively good bond performance, although its influence is not significant. Furthermore, the protective layer effectively attenuates the heating rate of the test pieces, thus safeguarding their bond performance. Scanning electron microscopy (SEM) analysis reveals that the decomposition of C-H and C-S-H phases is the primary cause of high-temperature degradation of the grouting material. Finally, a recommendation for the correlation coefficient (k) between the average bond strength and the compressive strength of the grout material is proposed, with a suggested value of k ≤ 2.58.

Thermal strengthening of seamless steel pipes grades 13KhFA for oil and gas industry

The present study focuses on grade 13KhFА steel alloyed with chromium and vanadium for the production of seamless pipes. The pipes were subjected to heat treatment throughout their body and along their entire length. They were fed individually into the furnace, end-to-end, consecutively. The heat treatment furnace was fueled by natural gas. Cooling of the pipes from the quenching temperature was achieved using water in a jet cooling multi-hole device (sprayer). This was followed by high self-tempering due to the heat retained after exiting the quenching furnace. Following quenching and high tempering, the structure of the 13KhFА steel on the surface of the pipe consisted of a mixture of ferrite and carbides with a granular carbide morphology (tempered sorbite). This structure enhances the corrosion resistance of the steel and provides an optimal combination of strength and toughness. The hardening temperature for seamless pipes made of 13KhFА steel was set within the range of 915–920 °C, while the tempering temperature was maintained at 720–730 °C. This careful selection of quenching and tempering temperatures within the specified limits makes it possible to obtain an improved structure of the 13KhFА steel. Keywords: pipe steel; thermal hardening; economically alloyed steel; regulatory standards; corrosion resistance.

АВТОМАТИЗАЦИЯ НЕРАЗРУШАЮЩЕГО КОНТРОЛЯ СТАЛЬНЫХ ТРУБ

The article describes the structure of an automated line for monitoring continuity and thickness gauging of seamless steel pipes based on an ultrasonic testing installation.

SRPCNet: Self-Reinforcing Perception Coordination Network for Seamless Steel Pipes Internal Surface Defect Detection

SRPCNet: Self-Reinforcing Perception Coordination Network for Seamless Steel Pipes Internal Surface Defect Detection

Numerical simulation of multi-array spray cooling for hot rolled seamless steel pipes

Spray cooling technology is an efficient cooling method. In the industrial application, the large area cooling requires the multi-nozzle spray design. Reasonable selection of nozzle array form is particularly important. Therefore, the simulation is applied in this study to investigate the effect of the nozzle array on the spray cooling of steel pipes after the model is validated. A steel pipe with a diameter of 140 mm, a wall thickness of 20 mm, and a length of 350 mm is employed as the research object, with an initial temperature of 900 °C. The scheme has four options for double spray spacing: OLR = −15 %, 0 %, 15 %, and 30 %. The results show that when the OLR grows, the cooling area gradually diminishes, and the cooling area's average temperature and average surface heat flux fall and subsequently increase. When OLR=30 %, the best cooling zone shape is obtained. The minimum average temperature, 231 °C, is obtained when OLR = 15 %. After comprehensive analysis, the ideal spray spacing range is found at OLR = 15 %∼30 %. In order to study the nozzle array, spray nozzles are arranged in multiple rows according to OLR = 30 %. This study also explores the strategies of unidirectional inclined spray and opposite inclined spray for lessening the area of the hot spot. There are six nozzle array arrangements in total. By comparing the results, it is discovered that the inclined spray increases the cooling area and accelerates the surface cooling of steel pipes. Under the side-by-side unidirectional inclined spray and the staggered unidirectional inclined spray, the cooling areas are 146,868 mm2 and 142,914 mm2 respectively, the average temperatures are 157.09 °C and 154.28 °C respectively. It is indicated that side-by-side inclined spray and staggered inclined spray are the better nozzle array arrangement to obtain the maximum cooling efficiency.

Experimental study on the tensile performance of a large-diameter UHPC grouted sleeve with thread

An ultra-high-performance concrete (UHPC)-grouted sleeve with a large-diameter seamless steel pipe with threads and bolts was designed. To study the mechanical properties of this grouted sleeve, various factors, such as the grouts type, rebar, thread, and bolts, were considered to conduct a uniaxial tensile test on the grouted sleeve specimens. The bonding performance of the grouted sleeve under a combination of various factors was studied, and its working mechanism was discussed. The results showed that the failure modes of the test sleeve specimens included rebar fracture, rebar slip and grouts slip. The G1 (UHPC without basalt fibre) grouted sleeve showed the best bonding performance and bearing capacity. Bolts and inner wall threads of the sleeve improved the grouts–sleeve bond strength. However, the level of improvement was related to the bolt location, thread spacing and depth. The closer the bolt position was to the elastic section of the sleeve port, the more significant the bond performance improved. The thread could provide mechanical bite force. The greater the thread depth were, the greater the mechanical bite force; nevertheless, there was a threshold. Based on the thick-walled cylinder theory, the calculation model for stress on the sleeve surface was obtained; these calculations were used to analyse the stress–strain law on the sleeve surface.

Cause Analysis of Leakage Failure of Seamless Steel Pipe during Pipeline Pressure Test

By means of chemical analysis, tensile test, metallographic analysis, and energy spectrum analysis, the leakage causes of seamless steel pipe in the process of pipeline pressure test were analyzed. The analysis shows that the crack of steel pipe appears before rolling, and the non-metallic inclusions near the crack are the crack source or preferred path of steel pipe cracking. The leakage of steel pipe defects in the subsequent eddy current and ultrasonic inspection is one of the main reasons the unqualified steel pipe flows into the construction site and leads to the leakage of the pressure test.

A Camera Calibration Method for Limited Motion of Target in Space

In modern industrial production, vision measurement systems are widely used for product quality inspection. Camera calibration is a crucial step in vision measurement systems that directly affects the accuracy of measurement results. However, in practical applications, the limited space for measurement and restricted movement of calibration targets present new challenges for camera calibration. In this paper, we propose a camera calibration method that is suitable for calibration targets with limited movement space. This method only requires one image of the calibration target to complete system calibration, greatly simplifying the on-site calibration work. Experimental results show that our method has a re-projection error of 0.0187 pixels, indicating high reliability and applicability. The application of this method in the inspection of seamless steel pipes demonstrates its potential for practical industrial production.

THE FORMATION FEATURES OF PIPES STRENGTH CHARACTERISTICS MADE OF MASS GRADES OF AUSTENITIC STAINLESS STEELS AT ROOM AND ELEVATED TEMPERATURES

As part of the research on the development of a new standard for welded and seamless stainless steel pipes, the microstructure, phase composition and mechanical properties in the temperature range of 20-650 °C of pipe samples from austenitic chromium-nickel steels of the Fe-18Cr-10Ni family were evaluated. Significant spread of mechanical characteristics is shown, a quantitative assessment of the contribution of various hardening factors is carried out. It is noted that grain size and solid-solution hardening with carbon, nitrogen or titanium have the most significant effect on mechanical properties, providing up to 45% of the yield strength of steel. It is established that the temperature dependence of the tensile strength is determined by the resistance to the formation of deformation martensite and the intensity of the action of dynamic deformation aging.

Comparison of ductile iron and seamless steel pipes for use in grouted sleeve splices under monotonic and cyclic loads

Ductile iron is often used for grouted sleeves due to its excellent toughness and ductility. Considering the greater cost of ductile iron, less expensive seamless steel has received much attention for use in grouted sleeves. This paper presents the results of an investigation of the tensile performance of grouted sleeve splices made of ductile iron and seamless steel pipe. Static tests and hysteretic tests were conducted for grouted sleeve splices with rebars. The various tested parameters included different types of grouted sleeve splices and diameters of rebar (12, 16, 20, and 22 mm). The splices with ductile iron showed better performance than those with seamless steel. The failure mode of all specimens was rebar rupture in the static test. The residual deformation was larger for the splices with the seamless steel pipe than those with ductile iron pipe. When the diameter of the rebar was 20 mm, the residual deformation of the splices with seamless steel pipe was three times that of the splices with ductile iron pipe, although their ultimate bearing capacities were similar. This indicated good interfacial bonding performance of the specimens of splices with ductile iron pipe. With cyclic loading, the splices with ductile iron pipe showed better capacities for energy dissipation and plastic deformation than the splices with seamless steel pipe. The maximum lateral displacement of the splices with seamless steel pipe was 1.2 times that of the specimens with ductile iron pipe, which can be attributed to the transverse cracks observed at the free end of the interface between the grouting material and rebar in the case of seamless steel pipe. Thus, grouted sleeves with seamless steel pipes were recommended for use under static conditions with no strict limitations on deformation.

Experimental study on the mechanical properties and failure modes of BFRP bar anchor systems under static tension loading

Basalt fiber-reinforced polymer bars are lightweight composite materials with high strength, low density, and excellent corrosion resistance. The anchor system made from basalt fiber-reinforced polymer bars is worthy of being developed and expected to be used in rock anchoring projects. In this work, four different basalt fiber-reinforced polymer anchor systems were designed, the influences of different design parameters on the ultimate bearing capacity of the anchor system were investigated through tension tests, and the failure modes of different anchor systems were elucidated. The test results indicated that failure modes, such as the transverse fracture of these bars and debonding of the bonding medium, were widely present in the wedge-modified anchor system and the steel-pipe-protected anchor system. These two anchor systems performed poorly with the wedge anchorage, whereas the basalt fiber-reinforced polymer bars protected by seamless steel pipes burst under the tension imposed by a universal testing machine. The threaded steel-pipe-bonded anchor system and the steel strand–basalt fiber-reinforced polymer bar composite anchor system had maximum anchorage efficiency coefficients of 97.7% and 98.5%, respectively. The bars in the corresponding test groups all exhibited burst failure, indicating that these two anchoring structures achieved effective anchorage of the basalt fiber-reinforced polymer bars.

Modelling of thermal shrinkage of seamless steel pipes using artificial neural networks (ANN) focussing on the influence of the ANN architecture

This paper presents two main novel findings. (1) The first finding is the development of an artificial neural network (ANN) model for thermal shrinkage of seamless steel pipes, which represents a new application for ANNs. Mill operators need such fast and accurate models to predict the final pipe outer diameter at ambient temperature based on the hot state immediately after rolling. The goal of this work was to lower the reject rate. However, small relative changes in the diameter are currently difficult to predict by using conventional ANNs. Therefore, a more sensitive target variable and a modified ANN architecture were applied to solve this problem. Data for training and validation were obtained from measurements on a hot-rolling mill. (2) The second finding is based on an investigation performed to determine the number of hidden neurons affected the model response, considering the data used. The knowledge obtained helps to determine the most suitable number of hidden neurons and to prevent overfitting. No generally accepted solution to these problems had previously been proposed in the literature. Consequently, this paper significantly supplements current research studies that describe applications of ANNs.

Effect of Normalizing on Impact and Corrosion Resistance of Low-temperature Service Seamless Steel Pipe

The seamless line pipe, which has fine low temperature impact properties for Low-temperature Service and good H2S corrosion resistance, was investigated through chemical composition designing, optimizing smelting-rolling processes, and heat treatment processes following ASTM A333 standard. The influence of normalizing on the impact property and corrosion resistance was studied by optical microscope, scanning electron microscope, transmission electron microscope, mechanical test and corrosion test. It is demonstrated that the low temperature mechanical properties and anti-H2S corrosion properties of hot-rolled trial-pipe and normalized trial-pipe meet ASTM A333 standard. The microstructure of hot-rolled trial-pipe is pearlite and ferrite, and the grain distribution is uniform and grain size is fine. The dominated precipitates phase are TiN particles in hot-rolled trial-pipe. Ductile to brittle transition temperature is determined at -60 °C. The grain refinement is achieved after normalized and the main precipitates are TiN particles together with a few VN particles. Ductile tobrittle transition temperature was further lowered, at - 80 °C. The corrosion behavior of the material was examined by hydrogen induced cracking (HIC) corrosion test, sulfide stress corrosion (SSC) test and polarization test at various polarization scanning rates. It is observed that the anti-HIC corrosion performance and SSC corrosion resistance are similar for both hot-rolled and normalized pipes, but the performance of electrochemical corrosion of normalized pipe is better than hot-rolled pipe, which indicates that the normalized pipe is more suitable for demanding corrosive environments.