High-strength or ultra-high strong steel laser-electrical arc composite heat source welding method

Abstract

The invention provides a novel high-strength or ultrahigh-strength steel laser-arc composite heat source welding method, which belongs to the technical field of the welding of high-strength or ultrahigh-strength steel. The method aims to solve the technical problem that the higher temperature needs to be adopted for preheating in order to prevent cold cracks during the welding of the high-strength or ultrahigh-strength steel. The welding method mainly comprises the following steps: the laser power is higher than 800 watts, a composite form that laser (2) is ahead and electric arc (3) follows is adopted along the welding direction, the filament spacing h is controlled to between 3 and 7 millimeters, and an included angle theta between an electric arc welding gun (4) and the horizontal plane is between 45 and 60 DEG. When the method is used to weld, a composite heat source welding pool is elongated and the oscillation of the pool is sharpened, so that the solidification rate of pool metal is reduced and grains are refined, thereby reducing the cold crack sensitivity during the welding process of the high-strength or ultrahigh-strength steel. The welding method can reduce the preheating temperature of the welding of the high-strength or ultrahigh-strength steel, and even can realize high-strength non-preheating welding.

Description

Technical field: [0001] A new laser-arc composite heat source welding method for high-strength or ultra-high-strength steel proposed by the present invention belongs to the technical field of high-strength or ultra-high-strength steel welding, and particularly relates to the ability to significantly reduce the tendency of cold crack cracking and welding of high-strength or ultra-high-strength steel welding. Laser-arc compound heat source welding method with preheating temperature. Background technique: [0002] As we all know, most high-strength or ultra-high-strength steels have a high tendency to harden. When welding high-strength or ultra-high-strength steels by conventional arc welding, the weld metal is prone to cold cracks. In order to prevent welding cold cracks, welding The workpiece to be welded needs to be preheated before, and the preheating temperature mainly depends on the chemical composition, strength grade, base metal thickness and welding structure of the hi...

AI Technical Summary

Problems solved by technology

Although pre-weld preheating can improve the cold crack susceptibility of welded joints, it brings a series of problems

On the one hand, the preheating before welding makes the welding process complicated and reduces the welding efficiency; on the other hand, the workpiece after high temperature preheating deteriorates the operating environment for workers; moreover, for some complex shapes or large sizes The workpiece cannot be preheated effectively, which brings great difficulties to the welding work

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