Titanium screws offer several advantages and distinctive characteristics. They can be welded using contact welding without requiring special preparation. However, if a thick oxide film is present, it needs to be removed through mechanical cleaning or by using a 5% hydrofluoric acid solution.
Arc welding of titanium screws is performed using clean gases like helium or argon, employing gas weaving techniques for optimal results. Direct current is typically used, with the tungsten electrode acting as the cathode.
Direct welding of titanium screws with nickel, bromine-chromium, and other nickel-containing alloys is not suitable due to the formation of harmful fusible eutectic crystals. In such cases, a spacer with a thickness of 15-20 microns, commonly made of molybdenum, tantalum, or niobium, needs to be placed between materials with different properties. Titanium screws or parts welded with nickel or nickel alloys can be effectively annealed and degassed in a vacuum or inert gas environment at temperatures up to 1500°C, ensuring specific conditions are met.
This welding method eliminates contamination in the joint area by other elements, as it doesn't require special solders or pre-metallization. It enables the creation of high-quality, vacuum-dense connections, making it a highly promising approach for titanium screws.
Now, let's explore the advantages and characteristics of titanium screws. During the alkaline cleaning process of titanium alloy rods, the alkaline solution is continuously removed or evaporated by the workpiece. Thus, it's important to replenish and adjust the solution promptly to maintain its composition stability.
For titanium screws, insoluble oxide slag precipitates at the bottom of the cleaning tank, affecting the tank body's thermal conductivity. This precipitation can create gaps that lead to electrochemical corrosion in steel tanks, significantly reducing their lifespan. Therefore, it's crucial to clean the sediment promptly. The use of a movable trough bottom to collect the slag is a common practice, facilitating easy removal of the sediment by lifting the movable tank bottom.
Yield strength refers to the maximum stress a metal material can withstand before undergoing a small amount of plastic deformation. In cases where metals lack a distinct yield point, the stress value that results in a residual deformation of 0.2 is considered the conditional yield limit or yieldstrength.
If external forces exceed the yield strength, the parts will experience irreversible deformation and cannot return to their original shape. For instance, low-carbon steel has a yield strength of 207 MPa. If the external force exceeds this limit, the parts will deform permanently, and reducing the force below this threshold will not restore the original appearance.
