Influence of Residual Stress on the HIC Resistance of High Frequency Induction Welded Pipes With Regard to Process-Specific Influencing Factors

2010 ◽  
Author(s):  
Joachim Kra¨geloh ◽  
Holger Brauer ◽  
Christoph Bosch
Keyword(s):  
Residual Stress ◽  
Influencing Factors ◽  
High Frequency ◽  
Negative Impact ◽  
Material Strength ◽  
Line Pipe ◽  
Cold Forming ◽  
Steel Coil ◽  
Sour Service ◽  
High Frequency Induction

Over the last decades an increase in the exploration and exploitation of impure oil and gas resources in remote environments under aggravated conditions has become necessary. This led to a growing demand for pipes with resistance to sour service conditions. Salzgitter Mannesmann Line Pipe has enhanced its product range of High-Frequency-Induction (HFI) welded pipes in recent years accordingly. In the process of HFI welding of pipes, forming roles bend steel coil into a pipe which is then welded together without any filler metal. This cold forming results in residual stress, depending on the diameter and wall thickness of the pipe. The current state of technology is based on the perception that this residual stress has an adverse effect on the resistance of line pipes to HIC, because it amplifies — or if it is sufficiently high — even triggers the onset of HIC. Aim of this paper is to study the influence of residual stress on the resistance in HFI welded pipes to HIC with regard to process-specific influencing factors. Four material strengths are selected for the tests. The first three material strengths (API 5L Grade from Grade B up to X65) are intentionally produced from non sour service material in order to obtain sufficient HIC damage. The highest material strength examined is a sour service material alternative to ascertain whether under optimal material conditions HIC indications can result solely from high residual stress. Plate and pipe segments are examined by means of the cross-sectioning method for longitudinal and circumferential residual stress at the process steps that influence the residual stress. A series of experiments under simulated residual stress to determine the HIC resistance of these pipe materials in NACE TM0284 test solution A is carried out using the four-point-bend test according to ASTM G 39, usually applied in sulphide stress cracking tests of line pipe steels. A characteristic HIC value, the crack area ratio CAR, is determined as a function of C and Mn content and residual stresses. To verify the results, FEM was used to model a test bar with the same geometry and to re-calculate the above-mentioned case. The results of these experiments combined with the supporting theoretical considerations and modelling prove that in the case of HFI welded line pipes, the residual stress induced by the process has no negative impact on the resistance of HFI welded pipes to HIC.

scholarly journals Residual stress detection of welded parts based on excitation vibration response

2020 ◽  
Vol 17 (1) ◽  
pp. 172988142090518
Author(s):  
Xiaohan Liu ◽  
Guangfeng Shi
Keyword(s):  
Residual Stress ◽  
Process Parameters ◽  
High Frequency ◽  
Rapid Development ◽  
Welding Process ◽  
Vibration Signal ◽  
Resonance Analysis ◽  
Orthogonal Parameters ◽  
Set Up ◽  
High Frequency Induction

With the rapid development of the equipment industry, people pay more attention to the stress research of materials. However, there is no more suitable and effective method to detect the variation of residual stress. To find an efficient and useful method to analyze the residual stress of the welded parts, this article selects the Q235 component as the research object and produces a detection robot with the core of processing vibration signal and extracting signal data. In combination with the vibration signal extracted by the robot, we study the influence law of the residual stress of the material through numerical simulation and experimental verification. The detection of residual stress is related to the change in the number of taps of the robot and the increase or decrease in the number of taps of the robot. We used the vibration signal extracted by the robot and analyzed the orthogonal parameters of the high-frequency induction welding process parameters to obtain a set of the most unique process parameters: The tapping angle was 7° and the tapping frequency was 300 Hz. We also set up the robot to extract and analyze the vibration signal using four different hammerheads. The results show that the sub-resonance analysis results as the standard, the deviation of the steel head and the aluminum head hammer is about ±10, the result is more accurate, and the frequency of the nylon and plastic hammer is lower, because it is softer. When the hammer is struck, the contact time of the hammerhead with the workpiece is lengthened, so that a lower frequency can be excited.

Collapse Resistance Enhancement in UOE SAWL Line Pipes During Coating Heat Treatment for Ultra Deepwater Applications

2014 ◽  
Author(s):  
Fábio Arroyo ◽  
Harold R. León ◽  
Ronaldo Silva ◽  
Luciano Mantovano ◽  
Rafael F. Solano ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Large Diameter ◽  
Final Analysis ◽  
Material Strength ◽  
Line Pipe ◽  
Offshore Pipelines ◽  
Cold Forming ◽  
Collapse Resistance ◽  
Offshore Pipeline ◽  
Key Factor

Large diameter UOE pipes are being increasingly used for the construction of offshore pipelines and in the last few year, since oil discoveries are moving towards ultra-deepwater areas, such as Pre-Salt in Brazil, collapse resistance is a key factor in the design of the pipelines the demand for pipes with high thickness near the limits for fabrication and installation capacity. It is known that the cold forming, and the final expansion in the UOE line pipe manufacturing process, reduces the elastic limit of the steel in subsequent compression. Due to this, the DNV collapse formula includes a fabrication factor that de-rates by a 15% the yield strength of UOE Pipes. However, DNV also recognizes the effect of thermal treatments and the code allows for improvement of the fabrication factor when heat treatment or external cold sizing (compression) is applied, if documented. In previous work [1] it was presented the qualification of UOE pipes with enhanced collapse capacity focusing the use of a fabrication factor (alpha-fab) equal to 1. A technology qualification process according to international standard has been performed. The main aspects of the qualification process were presented and included significant material, full scale testing and final analysis. In this paper, we compare those results with the ones of the new qualification tests analyzing the more important variables affecting the collapse resistance such as ovality, compressive material strength, thermal treatment control, etc. This new qualification obtained even better results than the previous one, which will allow the use of a fabrication factor equal to 1 directly in deepwater and ultra-deepwater offshore pipeline projects with a possible reduction in material and offshore installation costs and also potentially enhancing the feasibility of many challenging offshore projects.

scholarly journals Distortion and Residual Stress Behavior of Super-High Frequency Induction Hardened Carbon Steel Bar with Small Diameter

2007 ◽  
Vol 56 (7) ◽  
pp. 615-621
Author(s):  
Daisuke SUZUKI ◽  
Koji YATSUSHIRO ◽  
Seiji SHIMIZU ◽  
Yoshio SUGITA ◽  
Motoki SAITO ◽  
...  
Keyword(s):  
Residual Stress ◽  
Carbon Steel ◽  
High Frequency ◽  
Small Diameter ◽  
Stress Behavior ◽  
Steel Bar ◽  
Super High Frequency ◽  
High Frequency Induction

Rapid Sintering and Synthesis of Nanostuctured FeCrAlSi-Al2O3 Composite by High-Frequency Induction Heating

2011 ◽  
Vol 49 (03) ◽  
pp. 231-236 ◽  
Author(s):  
Song-Lee Du ◽  
Sung-Hun Cho ◽  
In-Yong Ko ◽  
Jung-Mann Doh ◽  
Jin-Kook Yoon ◽  
...  
Keyword(s):  
Induction Heating ◽  
High Frequency ◽  
Al2o3 Composite ◽  
Rapid Sintering ◽  
High Frequency Induction

In-situ compaction and sintering of Al2O3 – GNP nanoparticles using a high-frequency induction system

2018 ◽  
Vol 60 (7-8) ◽  
pp. 727-732
Author(s):  
Uğur Çavdar ◽  
İ. Murat Kusoglu ◽  
Ayberk Altintas
Keyword(s):  
High Frequency ◽  
Induction System ◽  
High Frequency Induction

scholarly journals Evaluation of Heating Technique of Deformed Reinforcement Using High-Frequency Induction Heating System

2021 ◽  
Vol 11 (11) ◽  
pp. 4947
Author(s):  
Myung-hwan Lim ◽  
Changhee Lee
Keyword(s):  
Reinforced Concrete ◽  
Temperature Rise ◽  
High Frequency ◽  
Thermal Conduction ◽  
Rapid Heating ◽  
Heating System ◽  
Inductive Heating ◽  
Reinforced Steel ◽  
Induction Heating System ◽  
High Frequency Induction

To improve recycling quality, it is necessary to develop a demolition technology that can be combined with existing crushing methods that employ large shredding-efficient equipment. The efficient collection of bones in a segmentation dismantling method must be considered according to the procedure. Furthermore, there is a need for the development of partial dismantling technologies that enable efficient remodeling, maintenance, and reinforcement. In this study, we experimentally investigated the temperature-rise characteristics of reinforced concrete through partial rapid heating during high-frequency induced heating. Accordingly, the chemical and physical vulnerability characteristics of the reinforced concrete were verified by studying the thermal conduction on the surface of the rebars and the cracks caused by the thermal expansion pressure of the rebars. Furthermore, we aimed to verify the applicability of the proposed technology by specifying the vulnerability range of the reinforced concrete based on the heating range, as well as the appropriate energy consumption. We investigated the temperature rise and temperature distribution characteristics of the rebar surfaces based on diameter, length, bar placement conditions, heating distance, heating coil location, and output, using reinforced steel of grade SD345. Maximum powers of 5, 6, and 10 kW, and inductive heating were used to achieve satisfactory results.

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