Titanium rod and titanium materials welding process
In the welding of titanium rods and titanium materials, have a look at the characteristics of the process.
(1), the appearance of welded joints, showing a dark blue, gold color, the welding current is 150A 170A 180A welding parameters according to this. That joint oxidation is more serious, does not meet the technical requirements. This process is not desirable.
(2), the appearance of the weld appears golden purple, dark yellow, the welding current is reduced to 120A 150A 160A welding parameters according to this parameter. X-ray flaw detection without defects, but the mechanical properties of bending test failed, indicating the plasticity of welded joints significantly reduced, failing to meet the technical requirements. This process is also not desirable.
(3), the appearance of the weld is silver white, light yellow, welding current is 95A 115A 120A welding according to this parameter. X-ray flaw detection without defects, but the mechanical properties of bending test pass, tensile strength also meets the requirements of the performance of welded joints meet the technical requirements of this process is more appropriate. Titanium and titanium alloy welding, there is likely of coarse crystal, a direct impact on the mechanical properties of welded joints. Therefore, the choice of welding process parameters not only to consider the weld metal oxidation and formation of pores, but also consider the grain coarsening factors. It should try to use a smaller welding heat input,
Processes (1, 2) due to larger welding specifications, resulting in joint oxidation process (3) more intense. And microscopic autobiographic experimental results show that the joint grain coarsening level than the process (3) serious. Therefore, poor mechanical properties of welded joints.
The choice of gas flow to achieve the best protection prevails, excessive flow is not easy to form a stable flow, and increase the cooling rate of the weld, the world appears more α outer layer surface, resulting in microcracks. The lack of argon flow in the trash will result in a different oxidized color of the weld, while excessive flow will disturb the air flow in the main nozzle. Argon flow on the opposite side of the weld should not be too large as this will affect the gas maintenance of the first well on the front.
Titanium and titanium alloy TIG welding operation
1) TIG welding, welding wire and weldment should try to keep the minimum angle (10 ~ 15). Wire along the front of the pool smooth, uniform into the pool, shall not move the wire end of the argon maintenance zone.
2) Welding, the welding gun does not swing horizontally, when the demand swing, the frequency is low, undulating should not be too heavy, in order to avoid affecting the maintenance of argon.
3) When are breaking and welding finishes finishing, continue to maintain argon gas until welding seam and heat-affected zone metal are cooled to below 350, then remove welding torch.
1, titanium rod and titanium welding gas protection issues are the major factor affecting the quality of welded joints.
2, titanium rods and titanium welding should just try to use a small heat input.
3, TA2 TIG welding, should strictly control the origins of hydrogen, to avoid the occurrence of cold cracks. Together should be taken to avoid the occurrence of stomatal.
4, just strict welding technology in accordance with the need for welding, and the adoption of useful gas maintenance measures, you can get high-quality welded joints.
