Special Requirements That Need To Exist In the Environment of Welding Titanium Materials
Titanium welds generally refer to titanium welded pipe, titanium wire, titanium electrode and titanium fasteners. In order to prevent air pollution and ensure the performance and quality of titanium welds, it is necessary to protect titanium welds during GTA and GMA welding.
1. Use good protective gas
Argon is usually preferred over helium for the primary protection of torches due to its better arc stability. If higher voltages, hotter arcs, and greater penetration are required, argon-helium mixtures can be used. Excess torch may cause turbulence and shielding loss. After the formation of the weld pool, the protective gas should continue to be used, and the arc should be extinguished until the weld cools. Uncontaminated welds will be shiny and silvery in appearance.
2. Tail protection
Its primary role is to protect the cured titanium weld metal and associated heat-affected zone until temperatures reach 800°F (427 ° C) or lower. Tail protection is usually customized to fit specific torches and specific welding operations. The design should be compact and allow for uniform distribution of inert gases within the unit, and consideration should also be given to the possible need for water cooling, especially for large protective enclosures.
3. Back protection
The main purpose is to provide inert gas protection for welding and heat affected zone roots. Water-cooled copper liners (or large strips of metal) can also be used as heat sinks to cool the weld. Temporary shielding devices are very effective for titanium weldments in shop or field conditions. These materials include sealing the work piece completely with plastic and then flooding it with inert gas. Similarly, aluminum or stainless steel foil "tents" are used for welding and are flooded with inert gases as back-up protection. Proper inert gas ratio should be maintained until welding is complete.