The Application of Taguchi Method in the Process Parameters of Gas Tungsten Arc Welding to Explore the Effects of Flux on the Weld Peculiarities of Structural Alloy Steel
| Autor: | Fu-Chen Chuang, 莊富珍 |
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| Rok vydání: | 2010 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 In this study, the Taguchi method was used to find the optimal process parameters for gas tungsten arc welding. A 4-factor 4-level (L16) orthogonal array, the signal-to-noise ratio, and analysis of variance were employed to study the weld penetration and bead area in welding of structural alloy steel. Four welding process parameters namely, welding current, welding speed, electrode tip angle and arc length, are optimized with the objective of producing welded joint with higher penetration and minimum bead area. The welding current and the welding speed were the major parameters that influence the weld bead geometry. Besides, a confirmation test was conducted subsequently, and the results were found to be within the 95% confidence interval. The optimum conditions were determined, and then effect of flux on the weld peculiarities of structural alloy steel was evaluated. The results showed that the acidic fluxes increased the weld penetration effectively and some of fluxes were enough to obtain full penetration welds. Optical microscopy revealed that the matrix microstructure of the base metal was ferrite and pearlite, while the microstructure of the weld metal was bainite and martensite. Because of different microstructures, the hardness of the weld metal was significantly different from that of the base metal. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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