Laser welding method for ultrahigh strength armor steel

Abstract

The invention discloses a laser welding method for ultrahigh strength armor steel. The laser welding method comprises the following steps that step 1, preparation before welding is carried out; step 2, two to-be-welded workpieces are installed on a tool fixture; and step 3, a welding line between the two to-be-welded workpieces is welded, wherein welding parameters are that laser power is 2500-2700W, the welding speed is 600mm / min, pure argon gas protection is needed, the welding environment temperature is no less than 15 DEG C, the welded position preheating temperature is between 50 DEG C-100DEG C, and the wind speed of the welded area is limited below 1m / s, otherwise a wind blocking device is needed. The cooling speed of a connector is decelerated, brittleness of the connector is reduced, shaping toughness is improved, cold crack is avoided, and usability requirements of the connector to a vehicle are guaranteed.

Description

technical field [0001] The invention belongs to the technical field of armor steel welding, and in particular relates to a laser welding method for ultra-high-strength armor steel, which is applicable to the laser welding method for reducing the brittleness of joints of ultra-high-strength and high-hardness armor steel. Background technique [0002] At present, the ultra-high-strength thin armor steels 616, 601, 6211, and 685 used in my country's armored vehicle industry have a thickness of 3-9mm and a tensile strength of more than 1500MPa. beam laser welding process. The existing ultra-high-strength thin armor steel is usually welded by conventional arc welding, which is prone to deformation and cracks after welding. If high-energy beam laser welding is used, due to the large welding energy and high cooling rate, the joints after welding tend to be hardened. It will be more obvious. Welding with conventional welding parameters of ordinary steel plates will inevitably produc...

AI Technical Summary

Problems solved by technology

The existing ultra-high-strength thin armor steel is usually welded by conventional arc welding, which is prone to deformation and cracks after welding. If high-energy beam laser welding is used, due to the large welding energy and high cooling rate, the joints after welding tend to be hardened. It will be more obvious. If the conventional welding parameters of ordinary steel plates are used, cold cracks will inevitably occur during use, which is a difficult point in application.

Although there has been a lot of research on high-strength steel laser welding at home and abroad, and many achievements have been made, they are all work and applications for materials with ordinary hardness and strength, and most of them are used in products that only require strength but not plastic toughness. In terms of welding, the laser welding of high-strength, high-hardness armor steel with high carbon content, high alloying, and large welding volume has not yet achieved applicability.

[0003] The armor steel currently researched and applied in China has good strength and toughness, but because its carbon equivalent is as high as 0.90 or more, the weldability is poor. The welding seam will be hardened under rapid cooling due to the fast welding speed of the usual laser welding method. Generate cold cracks and affect the performance of joints