Friction Stir Seal Welding (FSSW) Tube-Tubesheet Joints Made of Steel

2015 ◽  
Author(s):  
Abdel Rahman Shuaib ◽  
Fadi Al-Badour ◽  
Nesar Merah
Keyword(s):  
Friction Stir Welding ◽  
Carbon Steel ◽  
Position Control ◽  
Welding Process ◽  
Steel Tube ◽  
Shielding Gas ◽  
Friction Stir ◽  
Hermetic Seal ◽  
Shoulder Diameter ◽  
Reported Study

This paper demonstrates the feasibility of successful seal welding process of tube-tubesheet joints using the relatively new friction stir welding (FSW) process. The purpose of the reported study is to develop the process parameters and to test the feasibility of friction stir welding ASTM 179 seamless cold-drawn carbon steel tube into an ASTM A516 Grade 70 tubesheet. All welds were performed in position control on a fully instrumented experimental friction stir welder using a water-cooled tool holder and a shroud for argon shielding gas. A proprietary tungsten-rhenium pin tool with a 1.54 mm pin length and shoulder diameter of 4.9 mm was used to perform the seal weld between the roller expanded tube and tubesheet. A steel plug was employed during each weld in order to maintain support for the weld throughout the circumference of the weld. Sound welds were achieved in the FSW of ASTM 179 seamless cold-drawn carbon steel tube into an ASTM A516 Grade 70 tubesheet. Welding was improved by avoiding tool contact with the tube plug or the flash of the previous weld. Though a root void has been observed, which is typical of partial penetration butt welds, it is believed that the weld would still achieve a hermetic seal. Tool wear features of the W-Re pin has also been documented.

scholarly journals Force feedback-based quality monitoring of the friction stir welding process utilizing an analytic algorithm

2020 ◽  
Author(s):  
P. Rabe ◽  
A. Schiebahn ◽  
U. Reisgen
Keyword(s):  
Friction Stir Welding ◽  
Monitoring System ◽  
Force Feedback ◽  
Weld Seam ◽  
Position Control ◽  
Welding Process ◽  
Quality Monitoring ◽  
Welding Parameters ◽  
Process Data ◽  
Friction Stir

AbstractThe friction stir welding (FSW) process is known as a solid-state welding process, comparatively stable against external influences. Therefore, the process is commonly used with fixed welding parameters, utilizing axial force control or position control strategies. External and internal process disturbances introduced by workpiece, gap tolerance, tool wear, or machine/tool inadequacies are rarely monitored, and conclusions about the weld seam quality, based on the recorded process data, are not drawn. This paper describes an advancement, improving on research into the correlation of process force feedback events or gradual force changes and the resulting weld seam characteristics. Analyzing the correlation between examined weld sections and high-resolution rate force data, a quality monitoring system based on an analytic algorithm is described. The monitoring system is able to accurately distinguish sound welds from such with internal (void) and external (flash) defects.

Effect of Shoulder Diameter on the Resulting Interfacial Regions of Friction Stir Welds between Aluminium and Copper

2011 ◽  
Vol 299-300 ◽  
pp. 1146-1150
Author(s):  
Esther Titilayo Akinlabi ◽  
Stephen Akinlabi
Keyword(s):  
Friction Stir Welding ◽  
Feed Rate ◽  
Rotational Speed ◽  
Force Feedback ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Stir Zone ◽  
Vertical Force ◽  
Friction Stir ◽  
Shoulder Diameter

This paper reports the effect of shoulder diameter on the resulting interfacial regions of joints between aluminium and copper produced by the friction stir welding process. The welds were produced using three shoulder diameter tools, viz; 15, 18 and 25 mm. This paper focuses on welds produced at a constant rotational speed of 600 rpm and feed rate of 50 mm/min varying the shoulder diameters. Analysis of the force feedback revealed that the advancing force, the downward vertical force and the torque increases as the shoulder diameter increases. Microstructural characterization was conducted on the joint interfaces and it was observed that the widths of the interfacial regions comprising of the Stir Zone and the Thermo – Mechanically Affected Zone (TMAZ) increases as the shoulder size increases.

scholarly journals Basic Tool Design Guidelines for Friction Stir Welding of Aluminum Alloys

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2042
Author(s):  
Elizabeth Hoyos ◽  
María Camila Serna
Keyword(s):  
Friction Stir Welding ◽  
Solid State ◽  
Aluminum Alloys ◽  
Welding Process ◽  
Design Guidelines ◽  
Fusion Welding ◽  
Basic Tool ◽  
Friction Stir ◽  
Shoulder Diameter ◽  
Welding Consumables

Friction Stir Welding (FSW) is a solid-state welding process that has multiple advantages over fusion welding. The design of tools for the FSW process is a factor of interest, considering its fundamental role in obtaining sound welds. There are some commercially available alternatives for FSW tools, but unlike conventional fusion welding consumables, their use is limited to very specific conditions. In this work, equations to act as guidelines in the design process for FSW tools are proposed for the 2XXX, 5XXX, 6XXX, and 7XXX aluminum series and any given thickness to determine: pin length, pin diameter, and shoulder diameter. Over 80 sources and 200 tests were used and detailed to generate these expressions. As a verification approach, successful welds by authors outside the scope of the original review and the tools used were evaluated under this development and used as case studies or verification for the guidelines. Variations between designs made using the guidelines and those reported by other researchers remain under 21%.

scholarly journals Friction Stir Welding of Aerospace Alloys

2019 ◽  
Vol 48 (1) ◽  
pp. 37-46
Author(s):  
Akshansh Mishra ◽  
Devarrishi Dixit
Keyword(s):  
Friction Stir Welding ◽  
Welding Process ◽  
Space Vehicles ◽  
Friction Stir ◽  
Aerospace Applications ◽  
Aerospace Alloys ◽  
Fuel Tanks ◽  
Higher Temperature ◽  
Solid State Joining ◽  
Joining Process

Friction Stir Welding (FSW) is a solid state joining process which possesses a great potential to revolutionise the aerospace industries. Distinctive materials are selected as aerospace alloys to withstand higher temperature and loads. Sometimes these alloys are difficult to join by a conventional welding process but they are easily welded by FSW process. The FSW process in aerospace applications can be used for: aviation for fuel tanks, repair of faulty welds, cryogenic fuel tanks for space vehicles. Eclipse Aviation, for example, has reported dramatic production cost reductions with FSW when compared to other joining technologies. This paper will discuss about the mechanical and microstructure properties of various aerospace alloys which are joined by FSW process.

Study of the Key Issues of Friction Stir Welding of Titanium Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1185-1190 ◽  
Author(s):  
Hui Jie Liu ◽  
Li Zhou ◽  
Yong Xian Huang ◽  
Qi Wei Liu
Keyword(s):  
Titanium Alloy ◽  
Friction Stir Welding ◽  
Melting Point ◽  
Titanium Alloys ◽  
Welding Process ◽  
High Strength ◽  
Liquid Cooling ◽  
Friction Stir ◽  
Key Issues ◽  
Aluminum And Magnesium Alloys

As a new solid-state welding process, friction stir welding (FSW) has been successfully used for joining low melting point materials such as aluminum and magnesium alloys, but the FSW of high melting point materials such as steels and titanium alloys is still difficult to carry out because of their strict requirements for the FSW tool. Especially for the FSW of titanium alloys, some key technological issues need to solve further. In order to accomplish the FSW of titanium alloys, a specially designed tool system was made. The system was composed of W-Re pin tool, liquid cooling holder and shielding gas shroud. Prior to FSW, the Ti-6Al-4V alloy plates were thermo-hydrogen processed to reduce the deformation resistance and tool wear during the FSW. Based on this, the thermo-hydrogen processed Ti-6Al-4V alloy with different hydrogen content was friction stir welded, and the microstructural characterizations and mechanical properties of the joints were studied. Experimental results showed that the designed tool system can fulfill the requirements of the FSW of titanium alloys, and excellent weld formation and high-strength joint have been obtained from the titanium alloy plates.

Effect of Friction Stir Welding Parameters on Thermal and Tensile Behavior of Aluminum Weldments Using Double Shoulder Tools

2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Tensile Behavior ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Base ◽  
Tool Pin ◽  
Strength And Ductility

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.

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