Tungsten cathode laser multilayer cladding repair method

Abstract

The invention belongs to the technical field of laser cladding, particularly relates to a tungsten electrode laser multilayer repairing process used for rare earth fused salt electrolysis, belongs to the technical field of laser cladding and particularly relates to a tungsten cathode laser multi-layer repairing method. The tungsten cathode laser multi-layer repairing method is characterized in that a necking-down part of a tungsten electrode is cleaned and polished at the room temperature, and an oxide layer and a corrosion layer are removed thoroughly; then a 4 kW CO2 laser and a numerically-controlled worktable are used, a HUST-IV type high-precision powder feeding device and a coaxial powder feeding nozzle are used for cladding three kinds of mixed powder including SiC powder, Pd powder and pure W powder to the surface of a workpiece row by row and line by line under the protection of the argon atmosphere; a single-way multi-layer deposition manner is adopted for laser cladding, and a multi-layer coating with the thickness ranging from 6.0 mm to 10 mm is obtained; and finally, flaw detection is conducted, and it is ensured that the defects of cracks, air holes and inclusions are avoided in a cladding layer. The repairing method has the beneficial effects that the combining performance is high, operation is simple, and high temperature oxidability resistance and fused salt corrosivity resistance are good.

Description

technical field [0001] The invention belongs to the technical field of laser cladding, and in particular relates to a tungsten cathode laser multilayer repair method. Background technique [0002] The production of rare earth metals by molten salt electrolysis often uses refractory and corrosion-resistant metal tungsten as the cathode. Tungsten cathodes generally work under the conditions of electrolyte electrolysis temperature of 1000~1100℃, electrolysis current of 5500~6000A, and electrolysis voltage of 10V. The service life of a ø80mm×780mm tungsten cathode is 6-7 months, and the most serious loss of tungsten cathode is the middle part above the molten salt liquid level, which is mainly related to the oxidation of the electrode at high temperature. [0003] In order to prolong the service life of the tungsten cathode, the tungsten cathode is usually turned around and installed, and the thinned part is placed below the molten salt liquid level to continue to use. However,...

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Problems solved by technology

[0009] After the applicant's search and verification: the repair of the "neck neck" part of the tungsten cathode has been completed by using the laser multi-layer cladding process. There is no relevant report in the domestic industry. At present, there are still some difficulties in processing refractory metals by laser cladding. Scientific research Workers need further innovative research