Steel Tube Production Research Articles

THE RESEARCH OF INFLUENCE SIZE STRAIN AND NUMBER OF DRAWS ON DIMENSIONAL ACCURACY OF SEAMLESS TUBES MADE OF STEEL E235 AND E355

The die drawing process is used as a final drawing operation, especially in the production of precise tubes of smaller diameter, while the advantage of the mentioned technology is a reduction of the drawing force and thereby also the decrease of the risk of possible tube rupture during the drawing process. The paper is focused on the research of the influence of the strain size and the method drawing process on the final thickness of the wall and the outer diameter of the tube during die drawing. The sinking drawing experiment was performed by single-pass and two-pass drawing technology to the final tube diameter Ø12 mm without inter-operational annealing. The output of the paper are bar graphs that allows to compare the influence of the strain size and the method of tube drawing technology (single-pass and two-pass) on the dimensional accuracy of the final Ø12 mm tubes made of E235 and E355 steel. The advantage of the single-pass drawing technology when achieving the required wall thickness within the prescribed tolerance (±10 %) would be a reduction of the number of draws.It was found that only in one case of the two-pass drawing technology of E355 steel tube production, the permitted positive tolerance of the tube wall thickness was slightly exceeded, in the case of increasing the reduction (size strain R) from 24 % to 32 %.

Online Cooling System and Improved Similar Self-adaptive Strategy for Hot-rolled Seamless Steel Tube

In conventional hot-rolled seamless steel tube production, the tube was air cooled to room temperature, and the enhancing of mechanical properties mainly depends on adding alloys elements and additional offline heat treatment. Control cooling was an effective method that can obviously enhance mechanical properties and widely used in hot-rolled strip and plate production lines. To realize control cooling process, an online control cooling equipment was introduced, which can implement the efficient and uniform cooling process for annular seamless tube. Meanwhile, the controller system was built to ensure online continuous cooling process quickly and stably. In order to guarantee precise temperature control, a temperature model based on energy balance and finite difference method was proposed. In addition, a self-adaptive strategy based on improved similar tube was obtained for temperature control, which builds the self-adaptive model combining constrained one pass clustering algorithm and kNN algorithm. Finally, the proposed online control cooling system and temperature model were applied in a PQF460 hot-rolled seamless steel tube production line, which greatly improved qualification rate whilst retaining a good control precision and stability.

Induction Preheating for the Submerged Arc Welded Steel Tube Production

Tenaris is a leading supplier of tubes and related services for the world’s energy industry that manufactures a complete range of seamless and welded steel tubular products. The welding facilities are located in North and South America, and perform three types of welding processes, namely Electric Resistance Welding (ERW), Spiral Submerged Arc Welding, and Longitudinal Submerged Arc Welding (LSAW). Regarding the ERW process, in recent years we studied both the welding using Comsol [1,2], and the ulterior seam heat treatment using an in-house developed FEM model [3,4]. During the LSAW process, after the plate is conformed through the UOE forming process, the butt joint of the pipe is welded in three phases, first of which aims at presenting the edges and joining them but without filling in the bevels, the second one is to fill in the seam region at the inside of the pipe and the third one to do this operation on the outside. The welds are made by melting with an electric arc the bare metal electrodes. Pressure is not applied on the pipe during welding. Depending on the final product properties sought, a preheating near the edges with a relatively narrow temperature range is required for these three welding stages. In this article we focus on the inductive preheating for the tack welding stage of a continuous production line; it involves an open tubular geometry whose edges are facing and separated approximately 10 mm. There is no need to reheat the full tube, but only a region of ±75 mm from the edges approximately. Given the geometry and the required localized preheating, usual solution would be bar type inductors as those used typically for seam annealing. Alternatively, cylindrical coils can be used instead of inductive bars. 2D and 3D numerical models of different inductor bars and cylindrical coils are used in order to assess both kinds of preheaters and to understand the advantages and disadvantages of each one.

Production Technology for Precision Seamless Steel Tubes from the Perspective of Microhardness Changes

The production of precision seamless steel tubes in Železiarne Podbrezová is using hot rolled tubes with multiple cold drawing passes and intermediate annealing. It utilizes intensive plastic deformation during cold drawing, taking full advantage of the microstructural state from a physical point of view. In this paper, optimization of technological processes for cold drawn tubes made from ferritic-pearlitic steel has been elaborated. We use microstructural and substructural analysis, dislocation hardening theory and stress analysis. The subject of this article is the experiment with multiple drawing passes and intermediate annealing for production of precision steel tubes with dimensions of 31.8 x 2.6 mm. The drawing itself consists of 5 processes (also called „runs“) with 7 drawing passes in total. The results presented show strain hardening of the material after drawing along with relaxation mechanism during intermediate annealing. The possibility of utilizing the microhardness values on intensity assessment of these processes is investigated, too.

Online Eccentricity Monitoring of Seamless Tubes in Cross-Roll Piercing Mill

Wall-thickness eccentricity is a major dimensional deviation problem in seamless steel tube production. Although eccentricity is mainly caused by abnormal process conditions in the cross-roll piercing mill, most seamless tube plants lack the monitoring at the hot piercing stage but only inspect the quality of finished tubes using ultrasonic testing (UT) at the end of all manufacturing processes. This paper develops an online monitoring technique to detect abnormal conditions in the cross-roll piercing mill. Based on an image-sensing technique, process operation condition can be extracted from the vibration signals. Optimal frequency features that are sensitive to tube wall-thickness variation are then selected through the formulation and solution of a set-covering optimization problem. Hotelling T2 control charts are constructed using the selected features for online monitoring. The developed monitoring technique enables early detection of eccentricity problems at the hot piercing stage, which can facilitate timely adjustment and defect prevention. The monitoring technique developed in this paper is generic and can be widely applied to the hot piercing process of various products. This paper also provides a general framework for effectively analyzing image-based sensing data and establishing the linkage between product quality information and process information.

Eccentric and Nonuniform Axial Force Analysis Based on Steel Tube Components of Recycled Resource

To make great use of recycled deserted solid and concrete confined by steel tube has been one of the most significant tasks for sake of green low-carbon production and environmental-friendly sustainable development, especially now, as the earthquakes in recent years have resulted in a host of deserted solids and concrete wastes. Engineering application of recycled-aggregate-concrete-filled (RAC-filled) steel tube is a new challenge facing humanity. Force of Steel tube components in practical engineering application is nonlinear and random. Owing to the difficulty in conventional method, it becomes a main subject to reveal the nonuniform axial force mechanisms of steel tube components. First of all, this article adopts finite element method (FEM) to simulate actual force, to analyze mechanics of axial force of steel tube components under uniform, nonuniform and eccentric conditions, thus building a mechanical model. Then the effect on the load capacity of steel tube caused by local factors such as steel tube components under different force conditions and deformation in the process of steel tube production is analyzed. Finally, the three force simulations of circular steel tube components in the diameter of 165mm, a wall thickness of 4mm and 2mm are carried out separately, it turns out that the error of component with a thickness of 2mm is 4.96% while the other is 7.35%. Obviously the simulation and experimental results fit relatively well. Besides, eccentric load is related to eccentricity: the larger the eccentricity is, the smaller the load capacity is. Moreover, it needs to be singled out that nonuniform capacity is greater than centralized eccentric axial load capacity. The research results demonstrate that different parameter selection,different force and manufacturing precision of steel tube and its component exert relatively high influence on load capacity of component. The results also indicate that variety of force conditions and deformation has to be considered in applications of RAC-filled steel tube. Thus, the research provides reference and basis for RAC-filled steel structure design and manufacturing.

An Evolutionary Neighborhood Search Algorithm for Flexible Job-Shop Scheduling Problem in Steel Tube Production

This paper focuses on the tube processing context in steel tube production and constructs a flexible job-shop scheduling problem (FJSP) model with consideration of the typical features and constraints. An evolutionary neighborhood search algorithm which consists of process consolidation (PC) strategy, production line adjustment (LA) strategy and elimination mechanism (EM) strategy is proposed. The computational tests show that the proposed algorithm has good performance.

Cooling of a Rotating Cylinder by a Subcooled Planar Jet - Influence of the Surface Velocity on Boiling Regime

Cooling from impinging jet is nearly compulsory in steel industry processing especially in Run Out Table processing and steel tube production because of the high heat transfer provided by the boiling of the subcooled water jet. As far as metallurgical phase transformations, residual stresses and deformations in the workpiece are concerned, the temperature drop during cooling must be controlled thanks to a full understanding of the heat transfer mechanisms. One of the main characteristic using jet impingement is that the transition boiling regime may exist for very high superheat and thus the Leidenfrost temperature is higher than in pool boiling; consequently, boiling curves generally have a particular shape in the transition boiling regime which is usually called “shoulder of flux”. In this study, an innovative experimental quenching device has been used for analyzing the effect of the wall velocity of the surface to be cooled on the boiling curves (i.e. heat transfer) and we especially point out that the “shoulder of flux” (i.e. transition boiling regime) is strongly dependent on the surface to jet velocity ratio (r*). We found that a very small increase of the wall velocity has a high influence on shoulder of flux collapse.

Implementation of a quality procedure based on Delphi method and the ISO/TS 16949:2009 in the production of stainless steel tubes for automotive exhaust systems

PurposeThe purpose of this paper is to present the application of a procedure for the quality control of stainless steel tubes produced for automotive exhaust systems from a leading company in the steel sector, based on the Delphi method in accordance with the ISO/TS 16949:2009 and the ISO 9000:2008. Using Delphi methodology, it was possible to identify the main problems in the production lines object of the study, the main defects and their causes. Statistical methods were used to monitor process compliance and capacity. The panel of experts involved in Delphi method was able to identify causes of non‐compliance and suggest corrective actions.Design/methodology/approachThe quality procedure implemented involves the application of the Delphi method and the ISO/TS 16949:2009 standard in conjunction with ISO 9000:2008 to the production line of welded tubes for exhaust systems. The statistical methods used to monitor the process were mainly control charts. Capability index, Cp and Cpk, were used to measure the process attitude to produce compliant outputs. Dimensional data were acquired by non‐destructive testing on diameters and X‐R charts were used to graphically represent the process state of control. Destructive tests were performed to monitor the welding quality and P‐chart were used to assess the proportion of nonconforming units.FindingsIn this work, a procedure was developed in order to characterize the production process of TXM tubes realized in the line 31 of the leader company plant. The use of Delphi methodology, in order to incorporate experts opinions in the quality control of stainless steel tubes, was one of the main points of this work. The panel of experts worked together to identify process issues, define their causes and propose corrective actions. The paper provides an overview about the quality approach of one of the world's largest companies in the production of steel and shows also how the statistical tools are used in order to manage process behavior.Originality/valueThe value of this paper is to illustrate an innovative approach to a real life quality problem; it demonstrates how the application of qualitative and quantitative quality instruments in accordance with technical specification can help in increasing and maintaining product compliance and in optimizing the management of resources.

Dynamic Hybrid Flowshop Scheduling with Batching Production

Based on the background of steel-tube production, this paper presents the dynamic hybrid flowshop scheduling with batching scheduling at the first stage, and establishes an integer programming model for this problem. The objective is to minimize the total weighted completion time. The Lagrangian relaxation algorithm is constructed to slove the above model where dynamic programming is presented to solve batch-level subproblems, and a two-stage heuristic is presented to construct a feasible schedule. Testing results on small to medium problem sizes show that this method can obtain satisfactory quality solution in a shorter computation time.

Construction of Steel Tube Concrete Arch Bridge after Axes Change

In this paper ,the axes of a three-span dumbbell-shaped steel tube concrete arch bridge was changed due to deviation in bridge piers, tie beam construction and steel tube production, thereby steel tube arch ring can not be closed, and suspender hole can not be aligned. The side-span hollow steel tubes were intercepted and adjusted for three times through calculation and analysis, therefore the structure stress is reasonable and achieved original design standards under the condition of not changing the original arch axes, and the bridge was successfully constructed, thereby providing reference for engineering staff.

Overview on the application of ISO/TS 16949:2009, in a worldwide leader company in the production of stainless steel tubes for automotive exhaust systems

This paper presents an overview on the quality approach of a company that is at the leading edge in the sector of stainless steel-based products and represents an example of best practice in pursuing a continual improvement and the customer satisfaction. In this study, the attention has been focused on the application of the technical specification ISO 16949:2009 in accordance with the ISO 9000:2008, for the quality control of stainless steel tubes produced for automotive applications in one of the company plant devoted to the realisation of welded tubes for mufflers and exhaust pipes. The case study examined demonstrates how the effective adoption of the standards can help in reaching the highest level of performances in the production process, giving high-quality products and consolidating the company position on the market.

A hybrid flowshop scheduling problem for a cold treating process in seamless steel tube production

Seamless steel tubes often have various categories and specifications, which further require complicated operations in production, especially in the cold treating process (CTP). This paper investigates the scheduling problem using the seamless tube plant of Baoshan Iron and Steel Complex as a study background. By considering the practical production constraints such as sequence-dependent setup times, maintenance schedule, intermediate material buffers, job-machine matches, we formulate the hybrid flowshop scheduling problem with a non-linear mixed integer programming model (NMIP). In addition, our model provides a flexibility to remove the permutation assumption, which is often a limitation in early studies. In order to obtain the solution of the above NMIP problem, a two-stage heuristic algorithm is proposed and it combines a modified genetic algorithm and a local search method. With real production instances, our computation experiments indicate that the proposed algorithm is efficient and it outperforms several other approaches. Industrial implementation also shows that such a scheduling tool brings a cost saving of more than 10% and it substantially reduces the computation time. Our study also illustrates the need of relaxing permutation assumption in such a scheduling problem with complicated operation sequences.

Multi-Objective Flexible Job-Shop Scheduling Problem in Steel Tubes Production

Abstract On the basis of the distinct characteristics of steel tube production process, the production scheduling problem of seamless steel tubes is described as flexible job-shop scheduling problem. Considering the parallel machines with capacity and speed constraint, maintenance of machines as well as intermediate inventory restriction, it is formulated as mixed-integer-programming(MIP) model to decide the flexible routes for every job and to optimize the sequence of jobs. The objective is not only to reduce delivery delay, but also to minimize idleness of machines and interruption in production. Given the problem is NP-hard (non-deterministic polynomial-time hard), modified genetic algorithm is proposed, whose effectiveness can be well verified in scheduling decision support system for the production of seamless steel tubes in Baoshan Iron & Steel Complex.

Friction Coefficient Between Rolling Tube and Mandrel of Full Floating Mandrel Mill

In the process of steel tube production, continuous tube rolling is the foremost forming procedure and the critical step that decides the dimension precision and the surface quality. In the actual production of the ϕ140 mm full floating mandrel mill in Steel Tube Branch in Baosteel, steel T91 was chosen to be the typical sample, self-made rolling force transducer and mandrel velocity testing equipment were used, and a series of comprehensive tests on rolling parameters including the rolling force and mandrel velocity were carried out. After the experiment, the friction state between rolling tube and mandrel was analyzed. The friction coefficient was calculated and the values of 0. 033 − 0. 074 in each mill were obtained. The friction coefficient increases obviously along the rolling direction.

Growth of steel-tube production

Russia has seen a stable increase in the production of steel tubes in recent years, with the output of these products reaching 7,898,000 tons in 2006 and 8,706,000 tons in 2007. The trends in the use of the various types of steel tubes remain the same as in previous years: the demand for small-and medium diameter welded pipes is decreasing, while increases are seen in the use of welded large-diameter pipes and seamless pipes that can be used to extract and transport oil and gas; seamless pipes will continue to be displaced by welded pipes, with the production of the latter now accounting for 58% of all tubular products being made. In the next few years, Russian manufacturers will be busy modernizing their equipment and introducing new facilities for the production of quality semifinished products and finished tubes meeting world standards. The future of the Russian tube industry lies both here and abroad. As much as 25% of its products are already being exported, and Russia’s leading position in terms of its reserves of oil and gas, the long distances that oil and gas must be transported, and the fact that several large pipeline projects are already under way also make the prospects for growth in the domestic market quite promising.

A case of rule-based heuristics for scheduling hot rolling seamless steel tube production

Abstract: A production scheduling problem for hot rolling seamless steel tube at Tianjin Pipe Corporation of China is studied. Considering the complexity of the problem and the acceptable time for solving it, a rule-based heuristic approach is proposed and implemented. The proposed approach is a bottleneck scheduling method and considers simultaneously all production processes in three production units and ‘optimizes’ them as a whole. Additionally, the running result shows, on average, that a 3% increase in throughput and a 5% reduction in late deliveries have been achieved since the system implementation.

Optimal and near-optimal algorithms to rolling batch scheduling for seamless steel tube production

Abstract Seamless steel tube is one of the major products in iron and steel industries. Production of seamless steel tube is characterized as follows: (1) rolling batch is considered as a job to be scheduled; (2) the production process consists of multiple stages; (3) different setup times are required for different rolling batches to be processed; and (4) product variety is frequently changed on the same equipment. This paper takes the Tianjin Seamless Steel Tube Company (China) as the research background. The seamless Steel Tube Scheduling (SSTS) problem can be viewed as a flowshop scheduling problem with sequence-dependent setup times. The objective is to minimize the makespan considering rolling batches to be scheduled. For a small-scale problem, an optimal solution to the problem is found using a branch-and-bound method in which the lower bound is determined according to the m th (the last) machine in the flowshop scheduling. For a large-scale problem, a near-optimal solution to the problem is found by two-stage heuristic algorithms based on a neighborhood search method. Finally, the proposed optimal and approximate algorithms are implemented on a computer using Microsoft VC++6.0. A computational experiment with a large amount of randomly generated problem instances is designed to compare the performance of the algorithms. The following results can be drawn from the computer simulation experiments. For a small-scale problem, the proposed branch-and-bound can yield an optimal solution. The best heuristics can yield a near-optimal solution with an average 0.8% deviation from the optimal solution within a reasonable time.

Production of stainless steel tubes on A 140 tube mill

Production of stainless steel tubes on A 140 tube mill