Method for deep penetration laser welding of plate under assistance of ultrasound

Abstract

The invention relates to a method for deep penetration laser welding of a plate under the assistance of ultrasound. The method is characterized by comprising the following steps that firstly, first base metal (10) and second base metal (11) are machined to form butt joint end faces, and a series of inclined semicircular grooves are machined; secondly, the first base metal (10) and the second base metal (11) are in butt joint and are clamped, and a series of inclined blind holes are formed in a weld bead; thirdly, a first ultrasonic amplitude-changing rod (3) is pressed to the upper surface of a workpiece to be welded; fourthly, a second ultrasonic amplitude-changing rod (4) is fixed to one side of a laser welding head; fifthly, an ultrasonic generation device is started, the ultrasonic frequency is adjusted; sixthly, a laser beam (5) perpendicularly irradiates the upper surface of the workpiece, and the welding process is completed under continuous ultrasonic vibration; and seventhly, after welding is completed, ultrasonic vibration is maintained for 1-2 minutes. In the method, due to the pre-formed inclined blind holes and ultrasonic vibration, weld joint root leakage caused by molten pool downward flowing driven by local evaporation back flushing pressure of the front edge walls of the small holes is avoided.

Description

technical field [0001] The invention relates to a laser welding method, in particular to an ultrasonic-assisted laser deep penetration welding method for plates. Background technique [0002] Laser welding is one of the most widely used advanced processes in laser processing technology. It has the advantages of small welding heat input, large weld depth-to-width ratio, fast speed, small weld deformation and low residual stress, high welding precision and strength, no filler, easy The realization of outstanding advantages such as automation has been applied in important industries of the national economy such as automobiles, shipbuilding, nuclear power, and pipelines. [0003] With the recent successful development of ultra-high-power and high-brightness lasers, it is possible to use laser single-pass welding for thick plates. Laser deep penetration welding is similar to electron beam welding, and can obtain welds with large depth-to-width ratios. However, pure laser weldin...

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Problems solved by technology

[0009] The purpose of the present invention is to solve the welding defects such as root leakage and other welding defects due to the narrow range of welding process parameters in the forming process of the current high-power laser self-melting penetration welding thick plate (>12mm) flat welding joint

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