Porosity is a frequently encountered problem when welding Ti6AL4V titanium plates and tubes. The root cause of porosity formation is due to the influence of hydrogen. The formation of porosity in the weld metal mainly affects the fatigue strength of the joint. Hydrogen is the main cause of cold cracks and porosity formation. Because hydrogen is less than 300 degree , the solubility in the alpha phase is very small, with a limiting solubility of only 0.002% at room temperature. When the weld or heat-affected zone is cooled to below 300 degree after welding, the oversaturated hydrogen is precipitated in the form of titanium hydride ( phase). Correctly select the welding process parameters thoroughly remove the surface of the weldment, the surface of the wire on the oxide skin, oil and other organic matter. Control the flow of argon gas and flow rate to prevent turbulence, affecting the effect of inflatable protection. The use of manual tungsten argon arc welding titanium alloy welding treatment crack approach is feasible, can get satisfactory results.
|
Grád |
N |
C |
H |
Fe |
O |
Al |
V |
PaName |
Mo |
|
Ní |
TIName |
Gr1 |
0.03 |
0.08 |
0.015 |
0.2 |
0.18 |
/ |
/ |
|
/ |
/ |
/ |
bal |
Gr2Name |
0.03 |
0.08 |
0.015 |
0.3 |
0.25 |
|
/ |
/ |
/ |
/ |
/ |
bal |
Gr3Name |
0.05 |
0.08 |
0.015 |
|
0.3 |
0.35 |
/ |
/ |
/ |
/ |
/ |
bal |
Gr4Name |
0.05 |
|
0.08 |
0.015 |
0.5 |
0.4 |
/ |
/ |
/ |
/ |
/ |
|
|
Gr5 |
0.05 |
0.08 |
0.015 |
0.4 |
0.2 |
5.5~6.75 |
3.5~4.5 |
/ |
/ |
|
/ |
bal |
Gr7Name |
0.03 |
0.08 |
0.015 |
0.3 |
0.25 |
/ |
/ |
|
0.12~0.25 |
/ |
/ |
bal |
Gr9Name |
0.03 |
0.08 |
0.015 |
0.25 |
0.15 |
