Welding technology for manual argon arc welding of thick plate titanium material

Abstract

The invention discloses a welding technology for manual argon arc welding of a thick plate titanium material. The welding technology comprises the following steps: 1) cleaning welding wires, the surface of a groove and two sides of the groove; 2) adopting a double V-shaped groove, setting the angle of the lower section of the groove to be 55-70 degrees, and setting the angle of the upper section of the groove to be 30-35 degrees; 3) determining welding parameters, and welding. The application range of welding technology for manual argon arc welding of the titanium material is enabled to be further enlarged, and is particularly suitable for welding the titanium material of more than or equal to 20mm. The angle of the lower section of the groove is 55-70 degrees, so that a sufficient welding operation space is ensured, the defects of incomplete fusion, incomplete penetration and the like are prevented from being generated, and the welding quality is guaranteed; the angle of the upper section of the groove is 30-35 degrees, so that the metal filling volume is effectively reduced, and the difficulty requirements of improved groove processing technology is greatly reduced compared with U-shaped and double U-shaped grooves.

Description

technical field [0001] The invention belongs to the field of welding technology, and in particular relates to a manual argon arc welding process for thick plate titanium materials, in particular to a welding process for titanium materials with a thickness of more than 20 mm. Background technique [0002] The shell thickness of titanium equipment commonly used in domestic chemical plants is generally around 10mm, and the conventional welding parameters can meet the welding requirements. However, for the welding of slightly thicker titanium materials, especially the welding of plates above 20mm, the process parameters such as groove form, welding parameters, and gas protection vary greatly with the increase of plate thickness. When welding thick plate titanium alloys, the conventional groove form and welding parameters have a large amount of metal filling, large post-weld deformation and residual stress, and the number of total welding times is likely to have a negative impact...

AI Technical Summary

Problems solved by technology

However, for the welding of slightly thicker titanium materials, especially the welding of plates above 20mm, the process parameters such as groove form, welding parameters, and gas protection vary greatly with the increase of plate thickness.

When welding thick plate titanium alloys, the conventional groove form and welding parameters have a large amount of metal filling, large post-weld deformation and residual stress, and the number of total welding times is likely to have a negative impact on the mechanical properties and process properties of the weld. Problems such as low welding efficiency

[0003] Traditional thick plate titanium welding groove form, such as figure 1 A "X shape", figure 1 B "U-shaped", figure 1 C "Double U-shaped" grooves, among which "U-shaped" and "double U-shaped" grooves are difficult to process, have a long processing cycle, and the groove gap is narrow, making welding difficult; "X-shaped" grooves are metal too much filling

[0004] At high temperature, titanium will change from dense hexagonal close-packed α-titanium to β-titanium with coarse body-centered cubic lattice, resulting in a decrease in the plasticity of welded joints, and titanium has specific characteristics such as high melting point, large heat capacity and poor thermal conductivity. , so the welding of titanium should adopt the smallest possible welding heat energy, and the calculation formula of welding heat energy E is: (In the formula, η-power effective coefficient, U-welding voltage, I-welding current, V-welding speed interlayer cleaning), the traditional titanium welding process generally reduces the welding voltage (generally choose 10 ~ 12V), current (Generally choose 110-150A) to reduce the welding line energy. Although the welding line energy is controlled, the welding speed (generally 40-50mm / min) is relatively low, and the welding efficiency is greatly reduced. At the same time, the welding time is increased. number that increases the chance of a defect

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