济南镀锌板的焊接性能与未镀锌的同种钢板相比有明显的特殊性。虽然锌层厚度对于钢板板厚来说非常小，但是对于焊接性能的影响却很大。激光搭接焊中搭接板间隙间的锌蒸气将流向熔池部位，干扰熔池液相流动，造成飞溅和气孔，甚至出现严重的咬边等。

The welding performance of Jinan galvanized steel sheet has obvious particularity compared with the same kind of steel sheet without galvanizing. Although the thickness of zinc layer is very small for the thickness of steel plate, it has a great influence on the welding performance. In laser lap welding, the zinc vapor between the lap plate gaps will flow to the molten pool, interfere with the liquid flow in the molten pool, cause spatter and porosity, and even serious undercut.

济南镀锌板

Jinan galvanized sheet

镀锌板激光焊特征及缺陷：根据焊接机理，激光焊可分为两类即热传导焊与深熔焊。由于光斑尺寸差异，两者能量密度差别很大，前者主要用于材料的表面热处理，而后者在焊接领域应用广泛。激光深熔焊的本质特征为小孔效应，由于存在小孔，激光束能深入到材料内部，被熔化的液态金属环绕在小孔周围，激光对材料的热输入主要是在小孔壁上的液化界面上，随着激光束的移动，小孔前沿的金属被熔化、汽化，而在小孔后部，液态金属重新凝固形成焊缝，从而完成焊接过程。

Characteristics and defects of laser welding of galvanized sheet: according to the welding mechanism, laser welding can be divided into two categories, namely heat conduction welding and deep penetration welding. The former is mainly used for surface heat treatment of materials, while the latter is widely used in welding field. The essence of laser deep penetration welding is keyhole effect. Because of the keyhole, the laser beam can penetrate into the material, and the molten liquid metal surrounds the keyhole. The heat input of the laser to the material is mainly on the liquefying interface on the wall of the keyhole. With the movement of the laser beam, the metal in the front of the keyhole is melted and vaporized, while the liquid metal in the back of the keyhole is solidified again to form welding To complete the welding process.

激光焊接镀锌板的一个基本特征是产生等离子体，等离子体严重地阻碍激光束，降低板材对激光能量的吸收，不利于深熔焊时形成小孔及保持稳定；另一个特征就是在焊接过程中会形成锌蒸气，在对接接头中，锌蒸气在钢板的上、下表面可以自由膨胀散发到空气中去，而且锌烧损区域很小，一般为12mm(小于板厚)，接头的抗腐蚀性能没有受到太大损害。在激光搭接焊时，钢板间的锌蒸气很容易进入到熔池中去，产生一系列焊接缺陷，弱化接头性能。

One of the basic characteristics of laser welding galvanized sheet is the generation of plasma, which seriously obstructs the laser beam and reduces the absorption of laser energy, which is not conducive to the formation of small holes and maintaining stability in deep penetration welding; another feature is the formation of zinc vapor in the welding process. In the butt joint, zinc vapor can freely expand on the upper and lower surfaces of the steel plate and emit into the air Moreover, the zinc burning area is very small, generally 12mm (less than the plate thickness), and the corrosion resistance of the joint is not greatly damaged. In laser lap welding, the zinc vapor between steel plates is easy to enter into the molten pool, resulting in a series of welding defects, weakening the joint performance.