Mechanized ultrasonic testing for in-service inspection of tube to tube sheet welded joints fabricated by I.B.W. (internal bore welding) process

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

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Fracture Toughness of Different Locations in API X80 Pipeline Steel on Low Constraint SENT Specimens

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.853.251 ◽

2016 ◽

Vol 853 ◽

pp. 251-255

Author(s):

Hong Sheng Lu ◽

Yong He Yang ◽

Gang Chen ◽

Xu Chen ◽

Xin Wang

Keyword(s):

Welded Joints ◽

Weak Link ◽

Pipeline Steel ◽

Welding Process ◽

Resistance Curve ◽

X80 Pipeline Steel ◽

Three Samples ◽

Inner Surface ◽

Notch Orientation ◽

Low Constraint

With the considerable use of high-grade pipeline steel in onshore and offshore project, welded joints are recognized as the weak link in pipeline because of the non-uniform microstructural regions induced by welding heat input. At first, the microstructural of different regions in API X80 pipeline welded joints was characterized and quantified by SEM, which indicate that the pipeline steel is a typical acicular ferrite steel. In this paper we investigated the J-integral resistance curve (J-R curve) in different locations of API X80 pipeline welded joints through low constraint SENT specimens with side grooves at room temperature. The effect of notch orientation (longitudinal-radial (L-R) and transverse-radial (T-R)) on resistance curve were investigated in base metal, which reveal the orientation almost have no effect on resistance curve. As the welded joints adopted in this study is two-pass steel arc welds, so the J-R curves of the inner surface, the outer surface and through-thickness surface notches specimens in the weld metal were investigated. The inner surface sample have the highest toughness through three samples because of the effect of second pass welding process. The effect of constraint on resistance curve was conduct between low constraint SENT specimen and high constraint SENB specimen, which found that the lower constraint corresponding to the higher resistance curve. After finishing the test, crack advancing plan of different positions were etched and observed by OM to demonstrate that the crack path always in the region which we would like to test.

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Features of ultrasonic control of butt welded joints of polyethylene pipes

10.36652/0042-4633-2020-11-46-52 ◽

2020 ◽

pp. 46-52

Author(s):

N.P. Aleshin ◽

D.M. Kozlov ◽

L.YU. Mogilner

Keyword(s):

Quality Control ◽

Welded Joints ◽

Ultrasonic Testing ◽

Ultrasonic Inspection ◽

Mechanical Tests ◽

Ultrasonic Control ◽

Lack Of Fusion ◽

Polyethylene Pipes ◽

End To End

The reliability of ultrasonic testing (UT) of the quality of welded joints of polyethylene pipelines, made end-to-end with a heated tool, is considered in comparison with mechanical tests and radiography. The greatest detection of solid defects is provided by ultrasonic inspection with the use of chord tipe probes (not less than 90 %). When detecting defects translucent for ultrasound (lack of penetration, lack of fusion, etc.), the reliability decreases to 70÷80 %. Keywords: welding, polyethylene pipeline, quality control, ultrasonic testing, chord tipe probe. [email protected]

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Features of structure formation processes in AA2024 alloy joints formed by the friction stir welding with bobbin tool

Metal Working and Material Science ◽

10.17212/1994-6309-2021-23.2-98-115 ◽

2021 ◽

Vol 23 (2) ◽

pp. 98-115

Author(s):

Alexey Ivanov ◽

◽

Valery Rubtsov ◽

Andrey Chumaevskii ◽

Kseniya Osipovich ◽

...

Keyword(s):

Friction Stir Welding ◽

Structure Formation ◽

Welded Joints ◽

Heat Input ◽

Welded Joint ◽

Welding Process ◽

Tool Material ◽

Travel Speed ◽

Material System ◽

Friction Stir

Introduction. One of friction stir welding types is the bobbin friction stir welding (BFSW) process, which allows to obtain welded joints in various configurations without using a substrate and axial embedding force, as well as to reduce heat loss and temperature gradient across the welded material thickness. This makes the BFSW process effective for welding aluminum alloys, which properties are determined by their structural-phase state. According to research data, the temperature and strain rate of the welded material have some value intervals in which strong defect-free joints are formed. At the same time, much less attention has been paid to the mechanisms of structure formation in the BFSW process. Therefore, to solve the problem of obtaining defect-free and strong welded joints by BFSW, an extended understanding of the basic mechanisms of structure formation in the welding process is required. The aim of this work is to research the mechanisms of structure formation in welded joint of AA2024 alloy obtained by bobbin tool friction stir welding with variation of the welding speed. Results and discussion. Weld formation conditions during BFSW process are determined by heat input into a welded material, its fragmentation and plastic flow around the welding tool, which depend on the ratio of tool rotation speed and tool travel speed. Mechanisms of joint formation are based on a combination of equally important processes of adhesive interaction in “tool-material” system and extrusion of metal into the region behind the welding tool. Combined with heat dissipation conditions and the configuration of the “tool-material” system, this leads to material extrusion from a welded joint and its decompaction. This results in formation of extended defects. Increasing in tool travel speed reduce the specific heat input, but in case of extended joints welding an amount of heat released in joint increases because of specific heat removal conditions. As a result, the conditions of adhesion interaction and extrusion processes change, which leads either to the growth of existing defects or to the formation of new ones. Taking into account the complexity of mechanisms of structure formation in joint obtained by BFSW, an obtaining of defect-free joints implies a necessary usage of various nondestructive testing methods in combination with an adaptive control of technological parameters directly in course of a welding process.

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Design Considerations for the Use of Ultrasonic Phased Array Probes in Weld Inspection

Volume 2: Integrity and Corrosion; Offshore Issues; Pipeline Automation and Measurement; Rotating Equipment ◽

10.1115/ipc2000-199 ◽

2000 ◽

Author(s):

Paul A. Meyer

Keyword(s):

Ultrasonic Testing ◽

Phased Array ◽

Design Considerations ◽

Array Probe ◽

Ultrasonic Phased Array ◽

Weld Inspection ◽

Service Inspection

Ultrasonic testing of metal welds has been in use for many years. Scanning methods using both contact and immersion methods are often used at the time of manufacture and also during periodic in-service inspection programs. But because of a variety of component configurations and potential flaw geometries it is often necessary to perform several inspections, each with a different probe configuration to assure adequate defect delegability. It is possible that a properly designed phased array probe can perform several different inspections without changing hardware thereby reducing inspection times. This presentation reviews the design and operation of ultrasonic phased array transducers and the necessary features to achieve the desired performance. Situations in which these probes have already been implemented effectively are also discussed.

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Increasing of the Mechanical Properties of Friction Stir Welded Joints of 6061 Aluminum Alloy by Introducing Alumina Particles

Advances in Materials Science ◽

10.1515/adms-2017-0009 ◽

2017 ◽

Vol 17 (2) ◽

pp. 29-40 ◽

Cited By ~ 2

Author(s):

M. A. Tashkandi ◽

J. A. Al-Jarrah ◽

M. Ibrahim

Keyword(s):

Aluminum Alloy ◽

Base Metal ◽

Welded Joints ◽

Volume Fraction ◽

Welding Process ◽

Welding Zone ◽

6061 Aluminum Alloy ◽

Friction Stir ◽

Alumina Particles ◽

Welding Line

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.

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