There are 3 national standards related to the welding process methods of titanium and titanium alloys: GB/T 40801-202 "welding procedure qualification test of titanium, zirconium and their alloys", GB/T 36234-2018 "skill qualification of welders for fusion welding of titanium and titanium alloys, zirconium and zirconium alloys" and GB/T 37901-2019 "technical requirements for laser welding of high-temperature titanium alloys".
GB/T 37901-2019 Technical requirements for laser welding of high-temperature titanium alloys
The standard GB/T 37901-2019 specifies the technological process, quality requirements, and testing requirements of laser welded joints of high-temperature titanium alloys, the applicable material thickness, and material system are specified: applicable to the thickness of 0.5~8.0 mm, nearly α Type, α+β Type high-temperature titanium alloy (corresponding to type 52 and 53 specified in ISO/TR 15608).
Combined with the characteristics of the laser welding process of high-temperature titanium alloy, the standard mainly specifies 12 types of factors affecting welding quality or joint quality evaluation elements, specifically, it includes welding and inspection personnel, equipment, instruments and meters, base metal materials and filler materials, welding production environment, pre welding processing status of parts, pre welding cleaning and assembly of parts, product welding process evaluation, three quality grades of joints, joint appearance quality, weld surface color, the internal quality of welds, mechanical properties of joints (mainly transverse tensile strength), etc. At the same time, the standard also stipulates the scope and repair process of joint defects, and the inspection requirements and methods of joint welding quality. The standard covers a wide range of contents and is highly practical.
In addition, GB/T 37901-2019 standard also cites the defect classification method of metal fusion welding joints in GB/T6417.1-2005 and ISO 6520-1:1998, draws lessons from the defect types of high-energy beam welded joints in GB/T 22085.2-2008 and ISO13919-2：2001, and defines the defect quality and other limits and quality inspection methods in combination with the characteristics of laser welding and high-temperature titanium alloy materials, The technological process affecting the quality of laser welding of high-temperature titanium alloy is specified, and the overall level is equivalent to the international standard. It should be pointed out that the technical requirements of laser welding given in this standard also have guiding significance for the welding of other types of titanium alloys.
