Welding Of Tanks Research Articles

Research on welding defect examination technique based on phased array ultrasonic for high voltage transformer oil tank welds

Oil tank of high voltage transformer plates. During welding and operation, defects such as incomplete fusion, incomplete penetration , air holes and cracks may be produced which influence the integrity and density of the welds and the whole tank. In order to test the integrity of the shell weld of high-pressure transformer box and ensure no leakage of transformer oil, the phased array testing technology is used to detect the defects of the butt weld of the transformer oil tank. The characteristics of weld defect detection under the condition of incomplete penetration were studied, and the sound beam accessibility, process selection principle and probe selection principle were theoretically analyzed. The test tests were carried out on the artificial samples of the butt weld of the transformer oil tank plate. The results show that the phased array can effectively detect the defects in the weld of transformer tank shell under the condition of incomplete welding, and the imaging results are intuitive and easy to judge, which can effectively evaluate the integrity of transformer tank weld. During the process selection, the probe-wedge combination with appropriate front distance and detection Angle should be selected according to the wall thickness, weld penetration depth and crown width of the transformer oil tank. During defects judgment, the interference of structure echo wave and incomplete penetration area should be considered. The assistant defect positioning analysis based on incomplete penetration is also suggested.

Research on assembly scheduling problem with nested operations

A two-stage assembly scheduling problem with nested operations (nASP) is proposed to minimise the bi-criteria of makespan and the specified average passage time (Pave) in the rocket tank welding workshop. The nASP's tanks are assembled utilising a variety of parts and machining techniques. Depending on the type of tank, there are different numbers of usable parts. Additionally, at the first stage, parallel available machines, operation-dependent setup times, unpredictable rework, and dynamic machining times are considered. Eight heuristics and two lower bounds are first developed, then a logistic-based improved genetic algorithm (LBIGA) is presented while considering the characteristics of the solutions. To further optimize the Pave while maintaining the makespan, a heuristic built on backward computations is also suggested. Then, utilising the offered algorithms as well as genetic algorithm (GA), Tabu search (TS), and variable neighbourhood search (VNS) from the literature, randomly generated instances of nASP are resolved and compared. Ultimately, the numerical trials show the viability and efficacy of the presented algorithms.

Changes in the Mechanical Properties and Microstructure of High Manganese Steel by High Heat Input Welding and General Welding Processes

The demand for liquefied-natural-gas-fueled tanks on ships is growing in accordance with IMO 2020 regulations. The use of high manganese steel has increased recently, as this material can be applied at cryogenic service temperatures according to IGF code and has economic advantages over other materials. In this study, the high heat input welding process, which involves one-side submerged arc welding (SAW) welding with cut wire, is investigated to increase the productivity of high manganese fuel tank welding. The Flux cored arc welding and SAW welding processes are also evaluated and compared with the high heat input welding process. The mechanical properties of high manganese steel satisfied the class requirements and no precipitates were found in the weldment and heat-affected zone.

Wall climbing welding robot for automatic welding of spherical tanks

Wall climbing welding robot for automatic welding of spherical tanks

ANALISIS KELAYAKAN INVESTASI TEKNOLOGI ROBOTIKA PADA LINI PRODUKSI PT. A

This research purpose is analyzing investment feasibility on manufacture company related management plan. Company investment project in 2019 is robotic technologies application in production line assembly, robotic installation theme for 2019 is Six Axis Robot Tank Welding. Related this investment activity, required analyzing investment feasibility due avoiding finance loss after investment. Analyzing observing method for knowing feasibility value by using 3 aspect, base on stake holders concept (Suliyanto, 2013). Feasibility aspect during reasearch activity are market aspect , teknical & operation aspect & finance aspect, each aspect contain feasibility parameter for make judgement investment feasibility value on investment project. 
 Key words: Six Axis Robot, market aspect, technical & operation aspect, financial aspect

Application of Wall Climbing Welding Robot in Automatic Welding of Island Spherical Tank

Feng, X.-B.; Gao, L.-S.; Tian, W.; Wei, R.; Wang, Z.-W., and Chen, Y., 2020. Application of wall climbing welding robot in automatic welding of island spherical tank. In: Qiu, Y.; Zhu, H., and Fang, X. (eds.), Current Advancements in Marine and Coastal Research for Technological and Sociological Applications. Journal of Coastal Research, Special Issue No. 107, pp. 1-4. Coconut Creek (Florida), ISSN 0749-0208.With the rapid development of China's energy industry, marine energy exploitation has become an important part of China's oil supply, which has adjusted China's energy structure. Therefore, in the exploitation of offshore oil such as islands, spherical tank engineering has been greatly affected, which requires us to improve the automatic welding technology of wall climbing robot. Through the automatic welding technology of climbing wall welding robot, we can improve the welding quality and efficiency of spherical tank, which will improve the all position welding technology of spherical tank in China. Therefore, the disadvantages of low efficiency of traditional electrode arc welding process can't meet the needs of offshore oil storage and transportation, which requires us to improve the automatic welding technology of spherical tank wall climbing welding robot, which has become the dream of Offshore Petrochemical construction. Firstly, this paper analyzes the application of spherical tank welding robot. Then, the fusion welding forming model based on BP neural network is studied. Finally, this paper analyzes the key technology trend in the future.

Design and adsorption force optimization analysis of TOFD-based weld inspection robot

To meet the requirements of large metal tank weld inspection, a robot design scheme was proposed to walk on the outer surface of the tank and carry TOFD probe. The wall-climbing module, connecting frame module and TOFD weld inspection module are specifically designed. In this paper, the permanent magnetic adsorption principle and four-wheeled mechanism are both adopted in the wall-climbing module, meanwhile, the magnetic wheel’s adsorption force is analyzed under multiple parameters. The main parameters affecting the adsorption force are obtained. To ensure the minimum size and the lightest quality of magnetic wheel, the adsorption force is also optimized based on the main parameters which are related to the permanent magnet itself. The above work provides a reference value for the research and development of intelligent weld inspection products of large metal tanks.

К вопросу управления серводвигателями автоматической сварочной установки, предназначенной для сварки крупногабаритных ёмкостей ракет-носителей

К вопросу управления серводвигателями автоматической сварочной установки, предназначенной для сварки крупногабаритных ёмкостей ракет-носителей

Stress Concentration in Vertical Tank Weld Seams

The article describes a new method for analyzing and predicting the stress concentration coefficient in a rolled vertical tank weld seam under hydrostatic loading. Vertical tanks are widely used for storing petroleum products. The use of roll-to-roll assembly technology is advisable for a quick and inexpensive installation of oil tanks. However, the use of this technology in the installation of large-capacity tanks leads to the need to use thick rolled steel. This leads to the appearance of significant angularities of the weld seams used to fasten steel sheets in a roll. Such angularities are mechanical stress concentrators and can damage the tank. Therefore, the problem of modeling the dependence of stress concentration factors on the geometrical parameters of angularity is relevant and important to ensure both the economic and environmental efficiency of operation of the oil tanks assembled by the roll-to-roll method. The approach described in this article is based on a combination of a numerical experiment and an approximation approach. The stress concentration factor depends on two dimensionless parameters of the dent. Thus, a method of approximation of a two-dimensional problem is described. This method is applied to the data collected by numerous computational experiments using the finite element approach to construct an approximate model of the stress concentration factor. Such a model can be used to predict stress values, as well as tank strength and durability. The change in material properties in the weld seam is not taken into account. Thus, the estimated stress is higher than the real one and represents a majorant estimate. An approximating model of the stress concentration factor was constructed in the area of angularity of the weld seam of a 3,000 m3 complex structure oil tank under hydrostatic loading. The tank consists of four belts made of steel of various thickness. The density of the tank contents is close to that of water. It has been found that stress concentration increases as the distance to the tank bottom becomes smaller. Therefore, when building an approximating model, the results in the most strained region are considered.

GTT MARK III 스테인리스강 STS304L의 파이버 레이저 용접특성

레이저는 고밀도 열원으로써, 입열을 최소화하면서 고속용접이 가능한 장비이다. 특히 최근 상업화된 고출력 파이버 레이저는 특유의 발진원리 때문에 높은 빔품질과 소형화된 시스템이 가능하다. 이러한 장점들로 인해 파이버 레이저는 LNG 카고탱크에 대해 선박 내부에서 용접이 가능한 가장 적합한 열원이라고 판단된다.<BR> 따라서 본 연구에서는 선박산업에 레이저 용접기술을 적용하기 위해 파이버 레이저를 이용하여 LNG 선용 스테인리스강의 용접을 진행하였다. 연구에서 사용한 재료는 카고탱크에 사용되고 있는 오스테나이트계 스테인리스강인 두께 1.2mm의 STS304L였다. 레이저 출력 및 용접속도를 변화시켜가면서 겹치기 및 맞대기 용접을 실시한 후 용입특성을 분석하여 최적의 접합조건을 도출하였다. 그 결과 용접부에서 모재보다 우수한 기계적 성질을 얻을 수 있었다.

A Stable Tracking Control Method for an Autonomous Welding Mobile Robot

This paper proposes an Autonomous Welding Mobile Robot (AWMR) used in shipbuilding and large spherical tank welding and its control method. In this method, both the moving and rotating velocity of the mobile platform and the cross slider were controlled simultaneously. The stability of control method was proved through the use of a Liapunov function. Although any set of positive parameters makes the system stable, a condition on the parameters for the system being critically damped for a small disturbance is obtained through linearizing the system's differential equation. In the simulation, we analyzed line and circle-line tracking problem. And the tracking responses with and without velocity limited is also presented. It is shown that the output responses represent non-oscillatory property and effectiveness of the tracking method.

Development of a procedure for the ultrasonic examination of 9% nickel LNG storage tank welds using phased array technology

During construction of 9% nickel LNG tanks, weld examination is often done by conventional radiography. This paper presents the development of a procedure for the semi-automated ultrasonic examination using phased array technology in lieu of radiography.

Research on weld pool control of welding robot with computer vision

PurposeThe control of weld penetration in gas tungsten arc welding (GTAW) is required for a “teach and playback” robot to overcome the gap variation in the welding process. This paper aims to investigate this subject.Design/methodology/approachThis paper presents a robotic system based on the real‐time vision measurement. The primary objective has been to demonstrate the feasibility of using vision‐based image processing to measure the seam gap in real‐time and adjust welding current and wire‐feed rate to realize the penetration control during the robot‐welding process.FindingsThe paper finds that vision‐based measurement of the seam gap can be used in the welding robot, in real‐time, to control weld penetration. It helps the “teach and playback” robot to adjust the welding procedures according to the gap variation.Research limitations/implicationsThe system requires that the seam edges can be accurately identified using a correlation method.Practical implicationsThe system is applicable to storage tank welding of a rocket.Originality/valueThe control algorithm based on the knowledge base has been set up for continuous GTAW. A novel visual image analysis method has been developed in the study for a welding robot.

Lead Plated Sheet for Gasoline Tanks: Corrosion Resistance

A procedure of passivating lead-electroplated sheet is developed at Bardin Central Research Institute of Ferrous Metallurgy. The procedure substantially enhances the corrosion resistance and adhesion with paint coatings and has no effect on the welding of gasoline tanks.

パルス化高出力ＹＡＧレーザの厚板溶接への適用

Laser beam welding is used for small and thin parts that are required the high quality and precision. To weld large-scale and thick-wall products, high power laser beam must be transferred freely and deep penetration welding procedure must be developed. This paper will describe an optical fiber transmission system for 7 kW-class high power YAG laser and pulse modulated laser welding techniques to obtain deep penetration. The detailed observation of the weld pool and keyhole dynamics using high-speed camera and X-ray transmission system is carried out to understand high power YAG laser welding phenomena. It has been clarified that there are proper pulse duty and pulse duration for optimum-welding condition to obtain sound weld. Moreover it was revealed that bubbles, which were generated by the evaporation of metals near the bottom of keyhole, merged and disappeared into molten pool under N2 shielding gas. After confirmation of the high power YAG laser welding joint performance of stainless steel Type 304, this procedure has been applied to the welding of tanks for the nuclear fuel reprocessing plant.

容器・配管溶接の最新技術 ２ ＬＮＧ低温貯槽の溶接施工

容器・配管溶接の最新技術 ２ ＬＮＧ低温貯槽の溶接施工

In-fabrication and pre-service care on stainless steel pressure vessels

This paper discusses certain failure cases of austenitic stainless steel pressure vessels and components like dished ends due to improper specifications and inadequate care during fabrication, welding, hydrostatic testing and storage of tanks at coastal site. These failures are attributed to varous reasons such as residual stress, sensitisation, iron contamination and saline atmosphere. The paper also brings out the precautions to be taken during fabrication, storage and erection of austenitic stainless steel pressure vessels to avoid failures.

Automated interpretation of external tank weld radiographs : Reightler, R.E. Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19–24 Jul. 1992. Vol. 12A, pp. 881–887. Edited by D.O. Thompson and D.E. Chimenti, Plenum Press (1993). ISBN 0-306-44483-6.

Automated interpretation of external tank weld radiographs : Reightler, R.E. Review of Progress in Quantitative Nondestructive Evaluation, La Jolla, California (United States), 19–24 Jul. 1992. Vol. 12A, pp. 881–887. Edited by D.O. Thompson and D.E. Chimenti, Plenum Press (1993). ISBN 0-306-44483-6.

Conditions for achieving high-quality welds in the plasma-arc keyhole welding of structural steels

The present investigation describes the possibilities and the technological conditions for welding structural steels, especially high-strength steels, reproducibly and with high quality. The investigation comprises butt welding with an I-groove in the flat, horizontal vertical and vertical positions, and root welding of thick plates in the flat position. The investigation presents the welding-parameter combinations which results in the best quality welds. It has been shown that mechanized plasma keyhole welding is a very useful method for structural steels. It can compete successfully with common MIG/MAG and SAW welding as well as with electron and laser-beam welding, especially in large applications such as in the welding of large plates, box girders, tanks and pressure vessels, and large diameter pipes.

特集 低温貯槽の大型化と溶接技術の動向 地上式低温貯槽と溶接技術 現状と今後の展開

特集 低温貯槽の大型化と溶接技術の動向 地上式低温貯槽と溶接技術 現状と今後の展開