Browsing by Author "Tseng, Kuang-Hung"

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Effect of activated TIG flux on performance of dissimilar welds between mild steel and stainless steel
(2011)
Kuo, Cheng-Hsien
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Tseng, Kuang-Hung
;
Chou, Chang-Pin
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機械工程學系
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Department of Mechanical Engineering
The purpose of the present work was to investigate the effect of oxide fluxes on surface appearance, weld morphology, angular distortion, and weld defect obtained with activated tungsten inert gas (TIG) process applied to the welding of 6 mm thick dissimilar metal plates between JIS G3131mild steel and SUS 316L stainless steel. The CaO, Fe2O3, Cr2O3, and SiO2 fluxes used were packed in powdered form. The results indicated that the surface appearance of TIG welds produced with oxide flux formed residual slag. TIG welding with SiO2 powder can increase joint penetration and weld depth-to-width ratio, and therefore the angular distortion of the dissimilar weldment can be reduced. Furthermore, the defects susceptibility of the as-welded can also be reduced.
Sliding wear resistance of tempered D6ac steel
(2013-01-01)
Wu, Shyh-Chi
;
Wene, Hua-Chiang
;
Tseng, Kuang-Hung
;
Yau, Wei-Hung
;
Wu, Ming-Jhang
The aim of this study was to determine the sliding wear resistance of D6ac (tempered at room temperature, 450, or 550 degrees C) and to perform tribological responds. The obtained microstructures exhibited a heavy number of misfit dislocations from work hardening of the parent material, with the degree of disorder dislocation decreasing gradually upon increasing the temperature from 450 to 550 degrees C. XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides at 550 degrees C will result in a softer state than that of the room temperature specimen. The elevated temperature affected the tribological behavior and induced in the parent material a significant surface response failure. The lateral force increased gradually up to 50 mu N in the tempered cases, due to the enhanced toughness. We suggest that the increase in the coefficients of friction upon increasing the tempering temperature from 450 to 550 degrees C resulted due to a soft ferrite phase. Slightly stable fluctuations of the values of mu appeared for the surfaces scratched at a constant load; therefore, plastic deformation occurred along the wear path. For the measured results of the D6ac from room temperature to 550 degrees C, the coefficient of friction was 0.34 +/- 0.05, 0.27 +/- 0.04, and 0.13 +/- 0.02, respectively. The experimental result also can be evidenced from tribological stressing and mechanical behavior. (C) 2012 Elsevier Ltd. All rights reserved.
Tribological behavior of electron beam D6ac weldment
(2013-01-01)
Wu, Shyh-Chi
;
Tseng, Kuang-Hung
;
Wen, Hua-Chiang
;
Wu, Ming-Jhang
;
Chou, Chang-Pin
A flow formed D6ac steel tubing was joined using electron beam (EB) welding. Thereafter, the EB weldments were treated by tempering at temperatures of 450 degrees C and 550 degrees C. After tempering, the microstructural features, mechanical properties, and tribological characteristics of the EB D6ac weldment were studied. This study used a scratch test to evaluate the sliding wear resistance of the tempered weldment. Results indicate that the tempering softens the microstructure by reducing the dislocation density of the flow formed D6ac steel. For the 450 degrees C/2 h/air cooling tempering treated D6ac steel, the fracture toughness of the EB weldment can be significantly improved. The tribological behavior of the tempered D6ac weldment depended on the tempered microstructures. (C) 2012 Elsevier B.V. All rights reserved.