Method for measuring temperature of welding wire for laser hot wire welding

Abstract

The invention discloses a method for measuring temperature of a welding wire for laser hot wire welding. The method comprises the following steps: sending the welding wire to a base metal prewelding position at a preset wire feeding speed; heating the welding wire with preset heating current so as to enable the welding wire to generate resistance heat to enable the temperature to be increased; heating a target welding area by pulse laser with preset laser power, wherein the tail end of the welding wire is away from the center of a laser spot in a fixed distance and is heated; measuring the temperature of the welding wire within a light stop gap of the pulse laser. The method for measuring temperature of the welding wire for laser hot wire welding has the advantages of accuracy and reliability.

Description

technical field [0001] The invention belongs to the field of welding technology, in particular to a method for measuring the temperature of laser hot wire welding wire. Background technique [0002] Laser hot wire welding preheats the welding wire to a certain temperature through resistance heating and then sends it into the molten pool, which improves the stability of the welding process and cladding efficiency, and effectively expands the application of laser welding. Wire temperature measurement is the core technology for controlling wire transition stability and improving filling efficiency in laser hot wire welding. [0003] In the prior art, a temperature measuring probe is used to detect the temperature at the heating terminal of the welding wire to adjust the temperature of the welding wire, and the temperature probe used is a thermocouple or an infrared temperature measuring sensor. However, since the welding wire is in motion and the maximum temperature can reach ...

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Problems solved by technology

However, since the welding wire is in motion and the maximum temperature can reach the melting point, it is not suitable for contact temperature measurement using thermocouples; the front end of the welding wire is close to the molten pool, the strong reflection of the laser and the metal vapor above the molten pool strongly interfere with infrared temperature measurement, not only It makes it difficult to calibrate the emissivity coefficient after infrared temperature measurement. More importantly, if the laser wavelength is within the detection wavelength of the infrared temperature sensor, the strong reflection of the laser will directly lead to the failure of temperature measurement.

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