Laser welding method for realizing rapid splicing of high-strength steel

Abstract

The invention relates to a laser welding method for realizing the rapid splicing of high-strength steel. The laser welding method comprises the following steps of: step (1). using two hot coils of thehigh-strength steel as a forward coil and a backward coil respectively, shearing the band tail of the forward coil and the band head of the backward coil by using a double-cut shear, and then carrying out centering splicing; step (2). using a CO2 laser as a welding laser source, wherein a laser beam comes out of a reflector path of the laser source and then directly enters a light splitting device, and the light splitting device sequentially comprises a reflector, a spectroscope, and a focus lens; three laser beams are formed after the laser beam comes out of the light splitting device, the first laser beam falls before a spliced welding seam for preheating before welding; the second laser beam falls on the spliced welding seam to form a molten pool for laser welding; the third laser beamfalls after the spliced welding seam for post-weld annealing; controlling the energy ratio of the three laser beams by adjusting the power output of the laser source, the wedge angle of the spectroscope and the area of the laser reflecting surface; and step (3). controlling the light beam spacing of the three laser beams by adjusting the angle of the spectroscope, and controlling the focal depthof the three laser beams by adjusting the focus lens.

Description

technical field [0001] The invention relates to laser welding technology, in particular to a laser welding method for realizing fast splicing of high-strength steel. Background technique [0002] In the cold rolling continuous production process, it is very important to weld the end of the forward hot-rolled strip to the head of the subsequent strip to form a weld, and then make it pass through the rolling line to form continuous rolling, which can greatly improve Productivity. At this time, if the quality of the weld is poor, the weld will break when passing through the rolling line, resulting in production interruption. Due to the high quality of laser welding, no contact, large aspect ratio, small deformation, beautiful welding, and the mechanical properties of the weld are basically consistent with the base metal, it is suitable for welding in many fields, especially steel strips. High-strength steels are prone to welding hydrogen-induced cracks, welding stress, soften...

AI Technical Summary

Problems solved by technology

High-strength steels are prone to welding hydrogen-induced cracks, welding stress, softening of the heat-affected zone and decreased toughness, fatigue of welded joints, etc.

At present, when high-strength steel is produced by cold rolling mills, in order to obtain appropriate tensile strength, fatigue strength and good toughness at the weld and avoid hydrogen-induced cracks, the weld needs to be preheated before welding and annealed after welding. , this production method not only prolongs the production time and greatly reduces the production efficiency, but also increases the complexity of the equipment and increases the cost and difficulty of equipment maintenance

[0003] High-strength steels with a tensile strength ≥ 400MPa must be pre-welded and post-welded annealed in the production of cold rolling machines, and the welding time is long;

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