C.M.Cheng
,
C.P.Chou
,
I.K.Lee
,
H.Y.Lin
材料科学技术（英文）
In this study we conducted single V-groove butt welding (GTAW) on three types of heat treatable aluminum alloys 2024-T351, 6061-T6 and 7075-T6 and compared the angular distortion levels of the three aluminum alloys at different Vee preparation angles with or without restraint. Experimental results demonstrated that when the Vee preparation angle was 0℃ (I-shaped groove), the angular distortion level of the restrained weldment can exceed that of the unrestrained weldments. Moreover, when the Vee preparation angle was 45℃, 60℃ or 90℃, the restrained weldment had lower angular distortion than the unrestrained weldments. The single Vee preparation angle (amount of filler metal) in butt welding affected the angular distortion of the weldment. Without restraint, the angular distortion tended to increase with the single Vee preparation angle. Meanwhile, the angular distortion tended to decrease when the single Vee preparation angle was 60℃. Additionally, a restrained weldment had high angular distortion when the single Vee preparation angle was 0℃. Notably, the angular distortion tended to reduce with increasing single Vee preparation angle. The angular distortion of the weldment was minimized at an angle of 60℃. However, the angular distortion increased when the Vee preparation angle exceeded 60℃. The high-temperature yield strength of a material also affected its angular distortion. Angular distortion increased with high-temperature yield strength. Experimental results also showed that, from the strongest to the weakest, the high-temperature yield strength of the three types of aluminum alloys followed the order 6061-T6 and 2024-T351>7075-T6.
关键词:
Angular distortion
,
null
,
null
Heryueh HUANG
,
Shengwen SHYU
,
Kuanghung TSENG
,
Changpin CHOU
材料科学技术（英文）
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.
关键词:
TIG-flux welding
,
null
,
null
,
null
