The chemical properties of titanium materials are very active, especially at high temperatures, they are prone to react with elements such as oxygen, nitrogen, and hydrogen, leading to embrittlement of welds and decreased corrosion resistance. Therefore, the core idea of its prefabrication process is to isolate air through standardized processes and automated equipment in a controlled environment, ensuring high consistency and traceability of processing quality. The core of titanium welding is strict gas protection

    The color of titanium welds intuitively reflects the protective effect and degree of contamination during the welding process, and is the first criterion for judging whether it is qualified or not:

    Silver white/light straw color: perfect. Indicating excellent protection effect and no pollution.

    Golden yellow: Slight oxidation, usually acceptable (depending on project specifications), but already a warning.

    Blue/Purple: Moderate oxidation, usually unqualified, decreased corrosion resistance.

    Gray/off white powder: severely oxidized and contaminated, absolutely unqualified. The weld seam must be completely removed and re welded.

    The environment is also very important and must be carried out indoors in a dedicated, clean, well ventilated (but without ventilation) workshop. It is absolutely prohibited to carry out construction outdoors or in windy or dusty areas.

    Before welding, it is necessary to use a stainless steel wire brush to mechanically clean the groove and areas with a diameter of 25mm or more on both sides. Immediately thereafter, use acetone or methanol (chlorine free reagent) for chemical cleaning to thoroughly remove all pollutants such as oil stains, moisture, fingerprints, etc. It is absolutely prohibited to touch the cleaned groove with bare hands.

    Back protection drag cover: This is the soul of titanium welding. It must be specially designed and manufactured according to the pipe diameter and wall thickness to ensure coverage of high-temperature areas until cooled to below 400 ° C. The airflow should be uniform and stable. After welding is completed, the protective gas of the welding gun and drag cover cannot be immediately turned off. It should continue to blow until the weld cools to a safe temperature (about 250-300 ° C or below).

    Finally, radiographic testing (RT) and penetrant testing (PT) are carried out according to the process requirements to inspect internal and surface defects. Any repair must use the same or even stricter process specifications as formal welding