Pulsed laser welding method for high-pressure sealed valve body component

Abstract

The invention discloses a pulsed laser welding method for a high-pressure sealed valve body component and aims at providing a processing method for forming a continuous compact weld bead, which has the advantages of stable quality, higher efficiency, appropriate fusion depth of a joint after welding, regular weld joint, bright joint, uniform melting and mutually overlapped laser spots. The method disclosed by the invention is realized through the following technical scheme comprising the following steps of: (a) removing oxides on the surface of a weld and washing a joint part by a washing agent; (b) enabling a valve seat to be tightly close to a sealing gasket through a clamp, clamping on a three-jaw chuck, tilting a rotating table for 45 degrees and melting an angle joint of the valve body component; and (c) setting single pulse energy according to the characteristics of material and enabling a pulse waveform to be steep at the front and gentle at the back, thereby rapidly increasing laser energy to a peak value, rapidly heating, improving absorbability, then slowly lowering the temperature, maintaining the temperature for heating continuously, avoiding violent splashing, simultaneously increasing the fusion depth, melting the angle joint into a whole, matching with reasonable welding speed and pulse frequency, and enabling the laser spots to be mutually overlapped for forming the continuous compact weld bead.

Description

technical field [0001] The invention relates to a pulse laser welding method for a high-pressure sealing valve body assembly, in particular, it is suitable for high-pressure sealing products with different welding materials, high pressure resistance and low leakage rate. Background technique [0002] The valve body assembly is a typical high-pressure sealing product on an aero-engine, and its manufacturing precision directly affects the important characteristics of an aero-engine. Therefore, there are strict requirements on the connection of valve body components. Generally, there are two main ways to connect high-pressure sealing valve body components: overall machining and welding. [0003] Whole mechanical processing is adopted, the process is complicated, the manufacturing cost is high, and the production efficiency is low, which is not convenient for mass production, and the valve body assembly works in a special environment. The valve seat is made of heat-resistant st...

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Problems solved by technology

Using the conventional welding method—argon arc welding, the output heat is too large, the heat-affected zone is too wide, the welding deformation is serious, and the coaxiality cannot be controlled within 0.05mm, which cannot meet the requirements of use, and it is difficult to effectively control the welding quality from the process parameters. Control, can not fundamentally avoid welding deformation, resulting in parts scrapped

[0005] Using the conventional laser welding method, the power density is too high, the penetrating power is too strong, and the energy is too concentrated, which is prone to uneven surface formation, and the surface of the last 1 / 3 section of the weld has concave defects. The main reason for this defect is due to The gasket is too thin, the heat capacity is relatively small, and the temperature rise of the parts varies greatly during different periods of time during the welding process, especially in the last 1 / 3 section of the welding girth weld, due to the heating of the laser welding process and the heat conduction of the front weld seam , the temperature of the parts has been high, the melting amount of the weld metal is larger than that of the first 2 / 3 section, the weld shape is wider than the previous 2 / 3 section, and the depression of different depths is formed, resulting in serious deformation of the parts after welding, and the coaxial The welding depth cannot be controlled within 0.05mm. When the welding depth exceeds the seam line, it is very easy to cause local burn-through and welding leakage, resulting in the scrapping of parts

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