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Article

Weishan Huang, Jing-Li Luo, Hani Henein and Josiah Jordan

This paper aims to evaluate the sulfide stress cracking (SSC) resistance of L80 casing steels with different alloying chemistries (e.g. Ti-B and Mn-Cr-Mo) by correlating…

Abstract

Purpose

This paper aims to evaluate the sulfide stress cracking (SSC) resistance of L80 casing steels with different alloying chemistries (e.g. Ti-B and Mn-Cr-Mo) by correlating the reduction in area ratio with the mechanical property, inclusion and carbide.

Design/methodology/approach

SSC tests were conducted in 5.0 Wt.% sodium chloride and 0.5 Wt.% acetic acid solution saturated with H2S using constant load tensile method. The microstructure and fracture morphology of the steel were observed using scanning electron microscope. The inclusion and carbide were identified by energy dispersive spectroscopy and auger electron microscope.

Findings

Among all the testing steels, electric resistance welding (ERW) L80-0.5Mo steel demonstrates the highest SSC resistance because of its appropriate mechanical properties, uniform microstructure and low inclusion content. The SSC resistance of L80 steels generally decreases with the rising yield strength. The fracture mode of steel with low SSC resistance is jointly dominated by transgranular and intergranular cracking, whereas that with high SSC resistance is mainly transgranular cracking. SSC is more sensitive to inclusions than carbides because the cracks are easier to be initiated from the elongated inclusions and oversized oxide inclusions, especially the inclusion clusters. Unlike the elongated carbide, globular carbide in the steel can reduce the negative effect on the SSC resistance. Especially, a uniform microstructure with fine globular carbides favors a significant improvement in SSC resistance through precluding the cracking propagation.

Originality/value

The paper provides the new insights into the improvement in SSC resistance of L80 casing steel for its application in H2S environment through optimizing its alloying compositions and microstructure.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article

Wei Yan, Yong Xiang, Wenliang Li and Jingen Deng

This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion…

Abstract

Purpose

This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion design. CO2 partial pressure is the most important parameter to the oil and gas corrosion research for these wells which contain sweet gas of CO2. However, till now, there has not been a recognized method for calculating this important value. Especially in oil well, CO2 partial pressure calculation seems more complicated. Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. A case study was presented according to the new method, and two kinds of corrosion environment were determined. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. Based on the test results, 3Cr-L80 was recommended for downhole tubing. Combined with the field application practice, 3Cr-L80 was proved as a safety and economy anti-corrosion tubing material in this oil field. A proper corrosion parameter (mainly refers to CO2 partial pressure and temperature) can ensure a safety and economy downhole tubing anti-corrosion design.

Design/methodology/approach

Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. A field application practice was used.

Findings

It is necessary to calculate the CO2 partial pressure properly to ensure a safety and economy downhole tubing (or casing) anti-corrosion design.

Originality/value

The gas and oil separation theory and corrosion theory are combined together to give a useful method in downhole tubing anti-corrosion design method.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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Article

C. Miranda‐Herrera, I. Sauceda, J. González‐Sánchez and N. Acuña

The purpose of this paper is to evaluate the electrochemical behaviour of two carbon steels exposed to acidic geothermal solutions and their resistance to hydrogen induced…

Abstract

Purpose

The purpose of this paper is to evaluate the electrochemical behaviour of two carbon steels exposed to acidic geothermal solutions and their resistance to hydrogen induced cracking (HIC), in order to determine the effect of hydrogen damage on the failure process of the steels used for line pipe and casings at a geothermal plant.

Design/methodology/approach

Samples of two different steels: ASTM A‐53 Grade B (line pipe) and API L‐80 (casing) were immersed for a duration of 96 h in the electrolyte proposed by NACE to evaluate susceptibility to HIC. Samples of the two steels embedded in non‐conducting Bakelite were subjected to potentiodynamic polarisation scans at room temperature using as the electrolyte brines obtained from different wells at the Cerro Prieto geothermal plant. Hardness tests were performed on the samples before and after the HIC tests in order to determine hardness changes induced by hydrogen penetration as field results indicated embrittlement of the steels after four months of service.

Findings

The steels, ASTM A‐53 Grade B and API L‐80 did not exhibit crack sensitivity as no cracks are observed in the tests specimens, though they showed an increase in hardness. The steels exhibited high‐corrosion rates in the brine media at room temperature (3.3 mm/yr), which is expected to increase at higher temperatures.

Originality/value

The work revealed that carbon steels used for line pipes and casings at geothermal plants can exhibit high resistance to HIC, however they corrode at high rates and may show embrittlement. It is suggested that due to the high‐operation temperature, the damage induced by hydrogen resulted in hardness increase but was not sufficient to develop cracks.

Details

Anti-Corrosion Methods and Materials, vol. 57 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article

Subhradip Mukherjee, R. Kumar and Siddhanta Borah

The purpose of this work is to propose quad wheel robot with path navigation using an intelligent novel algorithm named as obstacle-avoiding intelligent algorithm (OAIA).

Abstract

Purpose

The purpose of this work is to propose quad wheel robot with path navigation using an intelligent novel algorithm named as obstacle-avoiding intelligent algorithm (OAIA).

Design/methodology/approach

The paper proposes OAIA algorithm, which is used to minimize the path distance and elapsed time between source and goal.

Findings

The hardware implementation of the Quad Wheel Robot design includes a global positioning system (GPS) module for path navigation. An ultrasonic module (HC SR04) is mainly used as the sensing unit for the system. In the proposed scheme, the GPS locator (L80) is used to obtain the current location of the robot, and the ultrasonic sensor is utilized to avoid the obstacles. An ARM processor serves as the heart of the Quad Wheel Robot.

Practical implications

This paper includes real-time implementation of quad wheel robot for various coordinate values, and the movement of the robot is captured and analysed.

Originality/value

The proposed OAIA is capable of estimating the mobile robot position exactly under ideal circumstances. Simulation and hardware implementation are carried out to evaluate the performance of the proposed system.

Details

International Journal of Intelligent Unmanned Systems, vol. 9 no. 1
Type: Research Article
ISSN: 2049-6427

Keywords

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Article

Xiaolong Lu, Shiping Zhao, Deping Yu and Xiaoyu Liu

The purpose of this paper is to describe the design and development of “Pylon-Climber”, a pole climbing robot (PCR) for climbing along the corner columns of electricity…

Abstract

Purpose

The purpose of this paper is to describe the design and development of “Pylon-Climber”, a pole climbing robot (PCR) for climbing along the corner columns of electricity pylon and assisting the electricians to complete maintenance tasks.

Design/methodology/approach

Introduces a PCR that is composed of a simple climbing mechanism and two novel grippers. The gripper consists of two angle-fixed V-blocks, and the size of V-block is variable. The clamping method of the angle bar meets the requirement of the force closure theorem. The whole design adopts symmetrical design ideas.

Findings

The developed prototype proved possibility of application of PCRs for inspection and maintenance of pylon. The novel gripper can provide enough adhesion force for climbing robot.

Practical implications

The robot is successfully tested on a test tower composed of different specification steel angles, oblique ledges and overlapping steel struts.

Originality/value

Design and development of a novel climbing assistive robot for pylon maintenance. The robot is able to climb along the column of electricity pylon and pass all obstacles. The gripper can reliably grasp the angle bar with different specification and overlapping steel struts from multiple directions.

Details

Industrial Robot: An International Journal, vol. 44 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

J.R. Carby‐Hall

Civil wrongdoings with consequent financial and other loss or damage to employers, employees and third parties may result in the course of various trade union activities…

Abstract

Civil wrongdoings with consequent financial and other loss or damage to employers, employees and third parties may result in the course of various trade union activities. These day to day trade union activities take a variety of forms. The most common ones are inducement of breach of contract, conspiracy, trespass, nuisance, and intimidation. Each of these activities constitutes a tort which, unless the statutory immunities apply, would normally give rise at common law to an action for damages or, as is more frequent, enable the aggrieved party to obtain an injunction.

Details

Managerial Law, vol. 29 no. 1/2
Type: Research Article
ISSN: 0309-0558

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Article

Jhonatan Jair Arismendi Florez and Jean Vicente Ferrari

Among the many influencing effects that the medium has on the CO2 corrosion of carbon steel, flow is one of the most important because it can determine the formation of…

Abstract

Purpose

Among the many influencing effects that the medium has on the CO2 corrosion of carbon steel, flow is one of the most important because it can determine the formation of corrosion product scales and its stabilisation, thus influencing the attack morphology and corrosion rate. This paper aims to summarise some factors affecting aqueous CO2 corrosion and the laboratory methodologies to evaluate one of the most important, the flow, with an emphasis on less costly rotating cage (RC) laboratory methodology.

Design/methodology/approach

Regarding the key factors affecting CO2 corrosion, both well-established factors and some not well addressed in current corrosion prediction models are presented. The wall shear stress (WSS) values that can be obtained by laboratory flow simulation methodologies in pipelines and its effects over iron carbonate (FeCO3) scales or inhibition films are discussed. In addition, promising applications of electrochemical techniques coupled to RC methodology under mild or harsh conditions are presented.

Findings

More studies could be addressed that also consider both the salting-out effects and the presence of oxygen in CO2 corrosion. The RC methodology may be appropriate to simulate a WSS close to that obtained by laboratory flow loops, especially when using only water as the corrosive medium.

Originality/value

The WSS generated by the RC methodology might not be able to cause destruction of protective FeCO3 scales or inhibition films. However, this may be an issue even when using methodologies that allow high-magnitude hydrodynamic stresses.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article

Xiaolong Lu, Shiping Zhao, Xiaoyu Liu and Yishu Wang

The purpose of this paper is to describe the design and development of “Pylon-Climber II”, a 5-DOF biped climbing robot (degree of freedom – DOF) for moving on the…

Abstract

Purpose

The purpose of this paper is to describe the design and development of “Pylon-Climber II”, a 5-DOF biped climbing robot (degree of freedom – DOF) for moving on the external surface of a tower and assisting the electricians to complete some maintenance tasks.

Design/methodology/approach

The paper introduces a pole-climbing robot, which consists of a 5-DOF mechanical arm and two novel grippers. The gripper is composed of a two-finger clamping module and a retractable L-shaped hook module. The robot is symmetrical in structure, and the rotary joint for connecting two arms is driven by a linear drive mechanism.

Findings

The developed prototype proved a new approach for the inspection and maintenance of the electricity pylon. The gripper can reliably grasp the angle bars with different specifications by using combined movement of the two-finger clamping module and the retractable L-shaped hook module and provide sufficient adhesion force for the Pylon-Climber II.

Practical implications

The clamping experiments of the gripper and the climbing experiments of the robot were carried out on a test tower composed of some angle bars with different specification.

Originality/value

This paper includes the design and development of a 5-DOF biped climbing robot for electricity pylon maintenance. The climbing robot can move on the external surface of the electric power tower through grasping the angle bar alternatively. The gripper that is composed of a two-finger gripping module and a retractable L-shaped hook module is very compact and can provide reliable adhesion force for the climbing robot.

Details

Industrial Robot: An International Journal, vol. 45 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

Peter G. Frankling

Looks at how hot melt adhesives (HMAs) can be used in product assembly and the white goods market in particular, e.g. washing‐machines, freezers, fridges, etc. because of…

Abstract

Looks at how hot melt adhesives (HMAs) can be used in product assembly and the white goods market in particular, e.g. washing‐machines, freezers, fridges, etc. because of the need for permanent or temporary bonds, gap seals and hole plugging. Concludes that HMAs are likely to be used more and more in related fields.

Details

Pigment & Resin Technology, vol. 25 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

J.C. VERITE

Problem 8 of the TEAM workshop comes from non‐destructive testing. A differential probe moves above a block with a crack. Three experimental and four numerical results are…

Abstract

Problem 8 of the TEAM workshop comes from non‐destructive testing. A differential probe moves above a block with a crack. Three experimental and four numerical results are presented and analysed. Some specific difficulties arising in this problem are discussed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 9 no. 3
Type: Research Article
ISSN: 0332-1649

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