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http://dx.doi.org/10.5781/KWJS.2009.27.2.063

Development and Strength Evaluation of Ring Projection Welding Process of the Microminiature Tube and Tubesheet  

Yun, Young-Hyun (Dept. of Shipbuilding Systems Management Engineering, Pukyong National University)
Kim, Hyun-Joon (R&D Center, Dong-Hwa Entec)
Kim, Chang-Soo (R&D Center, Dong-Hwa Entec)
Cho, Sang-Myung (Product & Welding Engineering, Pukyong National University)
Publication Information
Journal of Welding and Joining / v.27, no.2, 2009 , pp. 63-68 More about this Journal
Abstract
Microminiature heat exchanger has been applied to the gas turbine in order to increase energy efficiency. During the production of microminiature heat exchanger, however, it is very difficult to weld tube to tubesheet. In this study, therefore, welding process of resistance ring projection was used, and weld tensile tests were performed. Sound weld joint was obtained as a result of applying resistance ring projection welding to microminiature heat exchanger to tubesheet. Cold weld occurred at under 1600A. Even though tensile strength was increased with increasing current, splash occurred and tensile strength decreased at 2000A due to the excessive current. Therefore it was determine that the optimal current is 1900A. As result of tensile tests based on ASME code for tube to tubesheet weldment, rupture position was weldment due to Fs(Fractured section) of nugget, which was smaller than tube thickness (t), and it was proven as a partial strength welding because of the average joint efficiency fr = 0.90.
Keywords
Microminiature heat exchanger; Ring projection welding; Tube; Tubesheet; Electrode tip angle; Tensile strength; Tube extension; Welding current;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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