Butt Seam Research Articles

Effect of Post Weld Heat Treatment on Tensile Strength of ASTM A36 Welded Joints: Application on Hull Vessel Material

In fact, in the welding process, there are many problems that arise. Such as cracking caused by excessive stress Residual stress can result in a decrease in the mechanical properties of a material such as brittle fracture, fatigue, and cracking. The purpose of this study was to determine the comparison of tensile strength in ASTM plate welded joints A36 with variations of single vee butt and single bevel butt and knowing the comparison of the effects ofpost-weldd heat treatment on welded joints with variations of single v butt and single bevel butt joints. The method used in this research is experimental. The results of the data obtained in this study The value of the tensile strength of the Single Bevel Butt joint without the influence of Heat Treatment is 153.87 MPa, the tensile strength of the Single Vee Butt joint without the influence of Heat Treatment is 161.75 MPa and the tensile strength of the seam Single Bevel Butt with the effect of Heat Treatment is 196,65 MPa. The tensile strength of the Single Vee Butt seam with the effect of Heat Treatment is 173,36 MPa.

Investigation of Welded Joints Made of Construction Steel by the Barkhausen Noise Method

Steel weld seams are characterized by heterogeneity of their microstructure. Microstructure affects the nature of the distribution, sign and magnitude of residual stresses. In combination with unfavorable factors (low temperature, metal hypoductility and an unsuccessful joint form) residual stresses lead to a decrease of load carrying capacity of a whole structure. In a weld seam residual stresses are distributed in a complex way and can affect the build quality of heavy section welded structures. Monitoring of residual stresses remains a big problem. Residual stresses in welds are often evaluated only by modeling. Unfortunately, all mathematical models describe the stress state of the welded material with low accuracy. Simple quality control, the results of which can be easy interpreted, is necessary. Welded joints made by manual arc welding and by automatic submerged arc welding were investigated. Butt seams of steel sheets of different thickness have been welded. Steel was low-carbon and low-alloyed. It is often used in welded structures for various purposes, including construction, and for pipelines manufacture. The temperature range of welded structures operation is very large – from-70 to 450С. The authors studied the structure of butt weld seams by the Barkhausen noise method, which is interesting as it represents an alternative to the known methods, which characterizes the structure and stress state of material. The relationship between the weld microstructure and magnetic noise is shown. Studies have allowed us to establish the relationship between the structure and magnetic properties and to evaluate the feasibility of applying the Barkhausen noise method to welded structures.

Performance of MLI Seams between 293 K and 20 K

The performance of multilayer insulation systems (MLI) are often determined not by the bulk acreage insulation but rather by the design details that allow the insulation to be attached to the hardware it is insulating. To help understand the impacts of multiple different types of seams on blanket performance, calorimeter testing was performed at Glenn Research Center. Seams investigated included interleaved seams, butt seams, and overlapped seams; the latter two types of seams with multiple sub-blanket offsets built into the seam. Results showed that the interleaved seam had the best performance, and butt seams outperformed overlapped seams. Furthermore, if overlap seams are used, the sub-blankets should be overlapped by less than two inches.

Historic Paperhanging Techniques: A Bibliographic Essay

The purpose of this essay is to provide a context for installing reproduction wallpaper inhistoric homes. The trimming and borderwork found in surviving installations is discussed.Techniques for hanging wallpaper are described and linked to a bibliography about historicpaperhanging. Four chronological divisions are made:Early (1750-1860) - scissor trimming; overlapping; tacks, battens & canvas. Middle (1860-1900) - trimming machines; straightedges; track trimmers; muslin on boards.Late (1900-1940) - perforated selvedges; trimming knives; paneling; miter boxes.Modern (1940-1975) - butt seams; factory trimming; inlaid and overlaid borders; handscreens.Contemporary professional paperhangers follow rules about placing and balancing patterns inorder to hang wallpaper the right way. The installer either knows these parameters, or findsthem out. Another rule is that seams should show as little as possible. But, pursuit of a seamlessinstallation, if carried too far, can lead to a paradox: these days, a wallpaper installation issometimes most admired when it looks the least like a wallpaper installation. That is, when itshows no seams at all.This background helps to explain why overlapping, mismatching, and wavering scissortrimming — all marks of historic paperhanging — can challenge the contemporary eye. This canlead to uncertainty while restoring a historic home with reproduction wallpaper. Everyoneagrees that paper should be hung “the right way” for each period, but that way can be hard tofind. Other than examining well-preserved installations, it’s difficult to know much about howwallpaper was hung. Most information in the trade has been passed along by peers, or learnedon the job. Trade magazines are helpful, but they don’t begin until around 1875. Otherinformation is found tucked into books on wallpaper history, and in archival sources. It’simportant for researchers to know that wallpaper was most often called “paper-hangings” priorto 1900.

A precise seam tracking method for narrow butt seams based on structured light vision sensor

At present, most popular approaches of seam detection are based on structured light vision sensors owing to features of high accuracy and robustness. However, the deformation of laser stripe is not obvious enough when it is projected onto narrow butt seam, whose width is less than 0.2 mm, so the traditional structured light vision sensor cannot detect the seam feature of narrow butt seam. In this paper, a precise seam tracking method for narrow butt seams based on structured light vision sensor is proposed. Firstly, a new structured light vision sensor with optical filters and an extra LED light is developed to filtered out most of noises from strong arc lights and acquire the image including laser stripe and narrow butt seam. In addition, an image processing method for the vision sensor is designed to obtain welding torch deviations of narrow butt seams both in horizontal and vertical directions. Based on the obtained deviations, two independent Fuzzy-PID controllers are designed to achieve seam tracking control accurately. Finally, in order to verify the effectiveness of the proposed method in this paper, a welding experimental system is setup and welding experiments are carried out. Experimental results demonstrate that this method can meet the requirement of narrow butt seams tracking accuracy.

Microstructure and properties of high-power laser welding of SUS304 to SA553 for cryogenic applications

By matching with the welding speed, the distance between the laser focus and butt seam was adjusted to obtain various fusion ratios of the two base metals. The main phases in weld metal were martensite and retained austenite whose proportions and morphology were measured by XRD and EBSD, respectively. The proportion of retained austenite, both at grain boundary and among martensite laths in core region of grain, increased with the fusion ratio of SUS304. The maximum content of retained austenite at grain boundary and in core region of grain could reach about 22% and 5.8%, respectively. The low-temperature impact toughness of the joint was improved with the increment of retained austenite content. The low-temperature impact energy at −196°C had displayed a significant raise from 15J to 44.3J. The corresponding impact fracture section also transformed from cleavage fracture to entirely ductile fracture.

Determining seam profile tracking of very narrow butt welding on sheet metal

In this study, a welding manipulator has been designed in order to perform the butt-welding operation automatically of cylindrical sheet metals used in natural gas and heating systems. After the design procedure, the elements related to welding manipulator desired, has been defined and the test apparatuses was manufactured. In order to obtain profile of surface that will be welded on sheet metal, 2D laser profile sensor was used. A Personal Computer (PC) based software was developed and tested on the experiment set up in order to define the position of welding torch depends on profile data of welded area. The butt-welding process of two sheet metal shopped cylindrically was carried out automatically on test apparatuses. Key words: Image processing, seam tracking, laser 2D profile sensor, visual control algorithm, butt seam.

Tailored hybrid blank production—New joining concepts using different solders

A consistent lightweight concept necessitates the combination of different lightweight materials. Because of the significant weight reduction, multimaterial design is becoming more and more interesting for the transportation industry. Mixed material concepts are partially limited because of the insufficient deformation behavior of the joining seams. To overcome this limitation, a brazing process has been developed in which aluminium and steel can be joined, with an enhanced deformation behaviour. Tailored hybrid blanks with deep drawing ratios of 1.9 are possible. Process studies, metallographic analyses, and tensile tests were carried out for AA6016 sheets in combination with DX56D. The AA6016 surface has to be activated using a noncorrosive flux. Although it is possible to avoid melting of the aluminium base metal, intermetallic FeAl compounds occur and were characterized using energy dispersive x-ray analysis. It was proven that the intermetallic compounds affect the mechanical characteristics of the seam. During tensile tests, butt seams show approximately 70% of the strength of the weaker base metal. The results of cupping tests show the ultimate possibility of using tailored hybrid blanks in a various number of applications.

Experimental Modal Analysis Of A Water-filledCircular Cylindrical Tank

Experimental modal analysis has been performed on an empty and water-filled, circular cylindrical tank horizontally suspended. The tank is composed of a circular cylindrical shell with a longitudinal butt seam welding and two end annular plates. A rubber disk was glued to each annular plate to close the tank. The boundary conditions imposed to the circular cylindrical shell by the thin end plates can be considered very close to simply supports. Two little pipe fittings, used for supplying water, were welded to one of the end plates in such a position that they do not affect shell vibrations. The tank was hung to a truss with its axis kept horizontal by a compliant suspension, by using cables connected to the end plates. The Frequency Response Functions (FRFs) between 100 response points and one single excitation point (SIMO test) have been measured. Burst random has been used as excitation input. Natural frequencies and mode shapes are in very good agreement with theoretical data computed using the Fliigge theory of shells and potential and incompressible fluid model.