The choice of welding parameters will have a great impact on the structure of titanium welds and heat-affected zones. This is mainly due to the high melting point, large heat capacity, and poor thermal conductivity of titanium. If the welding parameters are selected large and the heat input is large, the high-temperature residence time will be longer and the high-temperature heat affected zone will be wider, which will make the weld and heat-affected zone grains Coarse, even the titanium plate and the base steel have mutual solubility.
The intermediate compound produced by the mutual dissolution is a brittle structure, which destroys and changes the original metal lattice, is a stress concentration point and a weak link in the weld increases the brittleness of the weld and reduces the plastic toughness and yield strength of the weld. The tensile strength makes the mechanical properties of the welded joints of titanium steel composite plate decrease sharply. Welds and heat-affected zones transform into needle-like structures during cooling, resulting in a decrease in the plasticity of welded joints. The heat input is too large. If the protective measures are not appropriate, the exposure of the weld and the heat-affected zone to the air will cause oxidation and discoloration, which will reduce or fail to meet the requirements for use; otherwise, the current is too small, the weld fusion cannot be guaranteed and the thermal effect The zone is hardened, which is not conducive to the escape of hydrogen, increases the tendency of cold cracking, and the construction progress is relatively slow. Therefore, the selection of welding currents must be reasonable and practical. The recommended construction site current is 110 ~ 150A, and the argon flow rate is 10 ~ 14L / min.
In the welding process of titanium filler strips, oxidative discoloration of welds and heat-affected zones and generation of cracks are common problems. The oxidative discoloration is mainly due to the excessively high surface temperature of titanium, which increases the activity of the titanium element and reacts with oxygen in the air during contact. Due to the different degrees of oxidation, the surface color is different. Different colors also mean whether the weldment can meet the requirements for use and whether it needs to be processed.
During the welding of titanium metal, attention must be paid to the protection of the weld seam and the heat-affected zone. The air chamber formed by the drag cover can be used for protection, or a large-nozzle argon arc welding torch can be used to expand the surrounding protective area.
titanium hexagonal rod titanium alloy powder medical titanium rod grade 2 titanium plate
The intermediate compound produced by the mutual dissolution is a brittle structure, which destroys and changes the original metal lattice, is a stress concentration point and a weak link in the weld increases the brittleness of the weld and reduces the plastic toughness and yield strength of the weld. The tensile strength makes the mechanical properties of the welded joints of titanium steel composite plate decrease sharply. Welds and heat-affected zones transform into needle-like structures during cooling, resulting in a decrease in the plasticity of welded joints. The heat input is too large. If the protective measures are not appropriate, the exposure of the weld and the heat-affected zone to the air will cause oxidation and discoloration, which will reduce or fail to meet the requirements for use; otherwise, the current is too small, the weld fusion cannot be guaranteed and the thermal effect The zone is hardened, which is not conducive to the escape of hydrogen, increases the tendency of cold cracking, and the construction progress is relatively slow. Therefore, the selection of welding currents must be reasonable and practical. The recommended construction site current is 110 ~ 150A, and the argon flow rate is 10 ~ 14L / min.
In the welding process of titanium filler strips, oxidative discoloration of welds and heat-affected zones and generation of cracks are common problems. The oxidative discoloration is mainly due to the excessively high surface temperature of titanium, which increases the activity of the titanium element and reacts with oxygen in the air during contact. Due to the different degrees of oxidation, the surface color is different. Different colors also mean whether the weldment can meet the requirements for use and whether it needs to be processed.
During the welding of titanium metal, attention must be paid to the protection of the weld seam and the heat-affected zone. The air chamber formed by the drag cover can be used for protection, or a large-nozzle argon arc welding torch can be used to expand the surrounding protective area.
titanium hexagonal rod titanium alloy powder medical titanium rod grade 2 titanium plate
No comments:
Post a Comment