LASER WELDING METHOD

• Main Authors: MATSUO RYUTA, SUGINO HIROKI, TAKIHITA KAZUHO, OGURA SHUHEI, KAWAI RYOSUKE
• Format: Patent
• Language: English; Japanese
• Published: 16.01.2020
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

To provide a laser welding method for lap-welding a plurality of metal plates, which can perform high-quality welding while surely allowing generated gas to escape, without being affected by quantities of gas generated during welding.SOLUTION: In the laser welding method, a plurality of laminated metal plates are lap-welded by irradiating laser beams to the plates. The plurality of metal plates are constituted of a first steel plate 11, a second steel plate 12 and a third steel plate 13 made of galvanized steel plates. The method includes: a dent forming step in which a dent 17 serving as an escape route of zinc vapor, which penetrates through the first steel plate 11 and the second steel plate 12 in a laminating direction to reach the third steel plate 13, by irradiating a first laser beam LB1 from the first steel plate 11 side; and a melting step in which a molten pool 16 is formed around the dent 17 in the first-third steel plates 11, 12 and 13 so as to keep a shape of the dent 17, by irradiating a second laser beam LB2 to the outside of the dent 17.SELECTED DRAWING: Figure 3 【課題】複数枚の金属板を重ね合せ溶接するレーザ溶接方法において、溶接時に発生するガス量に左右されることなく、発生するガスを確実に逃がしながら高品質の溶接を行う。【解決手段】レーザビームを照射することによって、積層された複数枚の金属板を重ね合せ溶接するレーザ溶接方法である。複数枚の金属板は、亜鉛メッキ鋼板からなる、第１鋼板１１、第２鋼板１２、第３鋼板１３で構成されている。第１レーザビームＬＢ１を第１鋼板１１側から照射することにより、第１鋼板１１から第２鋼板１２を積層方向に貫通して第３鋼板１３に達する、亜鉛蒸気の逃げ道となる窪み１７を形成する窪み形成工程と、窪み１７の外側に第２レーザビームＬＢ２を照射することで、窪み１７の形状を保持するように、第１〜第３鋼板１１，１２，１３における窪み１７の周囲に溶融池１６を形成する溶融工程と、を含んでいる。【選択図】図３