Browsing by Author "Shyu, SW"

Now showing 1 - 2 of 2

Effects of the process parameters on austenitic stainless steel by TIG-flux welding
(2006-05-01)
Huang, HY
;
Shyu, SW
;
Tseng, KH
;
Chou, CP
;
機械工程學系
The effects of the process parameters of TIG (tungsten inset gas)-flux welding on the welds morphology, angular distortion, ferrite content and hot cracking in austenitic stainless steel were investigated. Autogenous TIG welding process was applied to the type 304 stainless steel through a thin layer of activating flux to produce a bead on plate welded joint. TiO2, SiO2, Fe2O3, Cr2O3, ZnO and MnO2 were used as the activating fluxes. The experimental results indicated that the TIG-flux welding can increase the weld depth/width ratio and reduce the HAZ (heat affected zone) range, and therefore the angular distortion of the weldment can be reduced. It was also found that the retained ferrite content within the TIG-flux welds is increased, and has a beneficial effect in reducing hot cracking tendency for stainless steels of the austenitic type weld metals. A plasma column constriction increases the current density at the anode spot and then a substantial increase in penetration of the TIG-flux welds can be obtained.
Evaluation of TIG flux welding on the characteristics of stainless steel
(2005-09-01)
Huang, HY
;
Shyu, SW
;
Tseng, KH
;
Chou, CP
;
機械工程學系
The aim of the present study was to investigate the effect of specific oxide fluxes on the surface appearance, weld morphology, retained delta ferrite content, hot cracking susceptibility, angular distortion and mechanical properties obtained with the tungsten inert gas (TIG) process applied to the welding of 5 mm thick austenitic stainless steel plates. An autogenous gas tungsten arc welding process was applied to stainless steels through a thin layer of activating flux to produce a bead on plate welded joint. The MnO2 and ZnO fluxes used were packed in powdered form. The experimental results indicated that the 80% MnO2 - 20% ZnO mixture can give full penetration and also a satisfactory surface appearance for type 304 stainless steel TIG flux welds. TIG welding with MnO2 and/or ZnO can increase the measured ferrite number in welds, and tends to reduce hot cracking susceptibility in as welded structures. It was also found that TIG flux welding can significantly reduce the angular distortion of stainless steel weldments.