Investigation into keyhole-weld pool dynamic behaviors based on HDR vision sensing of real-time K-TIG welding process through a steel/glass sandwich

Abstract Self-developed high speed tandem TIG welding equipment were adopted to manufacture titanium welded tubes with high efficiency and high quality. The joint made by this high efficient welding process met Chinese standard requirements. A coupled electrode, arc and weld pool numerical model was also developed to investigate temperature and velocity distributions, and energy propagation of this welding process. The numerical results showed that the Marangoni stress was much higher than the arc shear stress, and was mainly positive after leading and trailing arcs in the x and y directions, so the molten metal flowed backward on the top weld pool surface. Previous studies proposed that a “pull-push” flow pattern defined as a backward molten metal flow after the leading arc and a forward molten metal flow before the trailing arc existed on the top weld pool surface in tandem arc welding processes, while it was not observed in this case. The calculated arc efficiency of the high speed tandem TIG welding was about 79.8%.

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The Reconsitution of the Weld Pool Surface in Stationary TIG Welding Process With Filler Wire

10.21203/rs.3.rs-116067/v1 ◽

2020 ◽

Author(s):

Jiankang Huang ◽

LIU Guangyin ◽

HE Jing ◽

YU Shurong ◽

LIU Shien ◽

...

Keyword(s):

Weld Pool ◽

Three Dimensional ◽

Welding Process ◽

Tig Welding ◽

Filler Wire ◽

Surface Evolution ◽

Recovery Algorithm ◽

Pool Surface ◽

Weld Pool Surface ◽

Dimensional Surface

Abstract In order to study the dynamic characteristics of the weld pool surface during the TIG welding process of the filler wire, an observation test platform for the study of the three-dimensional surface behavior evolution of the TIG weld pool based on the grid structure laser was used to observe the weld pool surface and obtain the reflection grid laser image. The three-dimensional surface evolution of the fixed-point TIG welding pool is accurately restored by the three-dimensional recovery algorithm of the weld pool surface, so as to obtain the three-dimensional surface morphology of the weld pool. The difference between the obtained weld pool height and the experimental results is very small, and the results are basically the same.

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In-Process Monitoring of Lack of Fusion in Ultra-Thin Sheets Edge Welding Using Machine Vision

Sensors ◽

10.3390/s18082411 ◽

2018 ◽

Vol 18 (8) ◽

pp. 2411 ◽

Cited By ~ 5

Author(s):

Yuxiang Hong ◽

Baohua Chang ◽

Guodong Peng ◽

Zhang Yuan ◽

Xiangchun Hou ◽

...

Keyword(s):

Real Time ◽

Weld Pool ◽

Process Monitoring ◽

Welding Process ◽

Thin Sheets ◽

Real Time Control ◽

Image Processing Algorithm ◽

Monitoring Method ◽

Lack Of Fusion ◽

Time Control

Lack of fusion can often occur during ultra-thin sheets edge welding process, severely destroying joint quality and leading to seal failure. This paper presents a vision-based weld pool monitoring method for detecting a lack of fusion during micro plasma arc welding (MPAW) of ultra-thin sheets edge welds. A passive micro-vision sensor is developed to acquire clear images of the mesoscale weld pool under MPAW conditions, continuously and stably. Then, an image processing algorithm has been proposed to extract the characteristics of weld pool geometry from the acquired images in real time. The relations between the presence of a lack of fusion in edge weld and dynamic changes in weld pool characteristic parameters are investigated. The experimental results indicate that the abrupt changes of extracted weld pool centroid position along the weld length are highly correlated with the occurrences of lack of fusion. By using such weld pool characteristic information, the lack of fusion in MPAW of ultra-thin sheets edge welds can be detected in real time. The proposed in-process monitoring method makes the early warning possible. It also can provide feedback for real-time control and can serve as a basis for intelligent defect identification.

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The reconsitution of the weld pool surface in stationary TIG welding process with filler wire

Welding in the World ◽

10.1007/s40194-021-01195-z ◽

2021 ◽

Author(s):

Jiankang Huang ◽

Guangyin Liu ◽

Jing He ◽

Shurong Yu ◽

Shien Liu ◽

...

Keyword(s):

Weld Pool ◽

Welding Process ◽

Tig Welding ◽

Filler Wire ◽

Pool Surface ◽

Weld Pool Surface

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Weld Pool Shape Variations and Electrode Protection in Double Shielded TIG Welding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.3978 ◽

2010 ◽

Vol 97-101 ◽

pp. 3978-3981 ◽

Cited By ~ 10

Author(s):

Dong Jie Li ◽

Shan Ping Lu ◽

Dian Zhong Li ◽

Yi Yi Li

Keyword(s):

Weld Pool ◽

Marangoni Convection ◽

Welding Process ◽

Tig Welding ◽

Width Ratio ◽

Mixed Gas ◽

Pool Shape ◽

Welding Method ◽

Weld Depth ◽

Weld Pool Shape

A new welding method named double shielded TIG welding has been investigated and is described in this paper. It is applicable to the TIG process and can improve the weld depth/width ratio and protect the electrode from oxidation during the welding process. A two pipeline structure is designed in the torch. Pure inert gas passes though the inner pipeline which keeps the arc stable and protects the tungsten electrode. A mixed gas containing an active gas passes through the outer pipeline. The active element which is decomposed from the active gas dissolves in the weld pool so as to change the Marangoni convection from an outward to an inward direction, and, as a result, the weld pool shape becomes deep and narrow. The double shielded TIG welding method increases the weld depth by about 2~3 times over the conventional TIG welding. The effects of the active gas (oxygen) in the outer pipeline on the weld pool shapes are discussed. Heavy oxide layer is considered to weaken the Marangoni convection and changes the weld pool shape.

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Numerical Modeling of Fluid Flow, Heat Transfer and Arc–Melt Interaction in Tungsten Inert Gas Welding

High Temperature Materials and Processes ◽

10.1515/htmp-2016-0120 ◽

2017 ◽

Vol 36 (4) ◽

pp. 427-439 ◽

Cited By ~ 5

Author(s):

Linmin Li ◽

Baokuan Li ◽

Lichao Liu ◽

Yuichi Motoyama

Keyword(s):

Heat Transfer ◽

Fluid Flow ◽

Weld Pool ◽

Welding Process ◽

Dynamic Mesh ◽

Tig Welding ◽

Mhd Equations ◽

Inert Gas ◽

Interface Deformation ◽

Flow Heat

AbstractThe present work develops a multi-region dynamic coupling model for fluid flow, heat transfer and arc–melt interaction in tungsten inert gas (TIG) welding using the dynamic mesh technique. The arc–weld pool unified model is developed on basis of magnetohydrodynamic (MHD) equations and the interface is tracked using the dynamic mesh method. The numerical model for arc is firstly validated by comparing the calculated temperature profiles and essential results with the former experimental data. For weld pool convection solution, the drag, Marangoni, buoyancy and electromagnetic forces are separately validated, and then taken into account. Moreover, the model considering interface deformation is adopted in a stationary TIG welding process with SUS304 stainless steel and the effect of interface deformation is investigated. The depression of weld pool center and the lifting of pool periphery are both predicted. The results show that the weld pool shape calculated with considering the interface deformation is more accurate.

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Weld pool formation and flowing behaviors of aluminum alloy during TIG welding process with a longitudinal electromagnetic field

QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY ◽

10.2207/qjjws.29.71s ◽

2011 ◽

Vol 29 (3) ◽

pp. 71s-75s ◽

Cited By ~ 3

Author(s):

Jian LUO ◽

Xiaoming WANG ◽

Dejia LIU

Keyword(s):

Electromagnetic Field ◽

Aluminum Alloy ◽

Weld Pool ◽

Welding Process ◽

Tig Welding ◽

Pool Formation

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Real-Time Weld Penetration Depth Monitoring With Laser Ultrasonic Sensing System

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2137747 ◽

2005 ◽

Vol 128 (1) ◽

pp. 280-286 ◽

Cited By ~ 25

Author(s):

Bao Mi ◽

Charles Ume

Keyword(s):

Real Time ◽

Penetration Depth ◽

Weld Pool ◽

Phased Array ◽

Welding Process ◽

Analytical Relationship ◽

Correlation Technique ◽

Weld Penetration ◽

Weld Quality ◽

Sensing System

A real-time ultrasound-based system for controlling robotic weld quality by monitoring the weld pool is presented. The weld penetration depth is one of the most important geometric parameters that define weld quality, hence, remains a key control quantity. The sensing system is based on using a laser phased array technique to generate focused and steered ultrasound, and an electromagnetic acoustic transducer (EMAT) as a receiver. When a pulsed laser beam is incident on the surface of a condensed matter, either the thermoelastic expansion or ablation induces mechanical vibrations that propagate as ultrasound within the specimen. Both the ultrasound generation by the laser phased array and the reception by the EMAT are noncontact, which eliminates the need for a couplant medium. They are capable of operating at high temperatures involved in the welding process. The ultrasound generated by the laser phased array propagates through the weld pool and is picked up by the EMAT receiver. A signal-processing algorithm based on a cross-correlation technique has been developed to estimate the time-of-flight (TOF) of the ultrasound. The relationship between the TOF and the penetration depth of the weld has been established experimentally and analytically. The analytical relationship between the TOF and the penetration depth, which is obtained by the ray-tracing algorithm and geometric analysis, agrees well with the experimental measurements.

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