Method for laser beam welding of a steel preliminary product with a metallic covering using a gas containing Ar, Co2 and O2

摘要

The method for laser beam welding of a primary steel product provided with a metallic coating under a protective gas, is claimed, where the coating contains high melting point alloy component that does not evaporate during welding. The metallic coating is included in a weld seam formed during welding, where the weld pool dynamics of the weld metal is influenced by welding using a shielding gas consisting of carbon dioxide (0.5-20%), oxygen (0.1-10%) and rest of argon such that the alloying elements of the metallic coating experience an intensive mixing with the weld metal. The method for laser beam welding of a primary steel product provided with a metallic coating under a protective gas, is claimed, where the coating contains high melting point alloy component that does not evaporate during welding. The metallic coating is included in a weld seam formed during welding, where the weld pool dynamics of the weld metal is influenced by welding using a shielding gas consisting of carbon dioxide (0.5-20%), oxygen (0.1-10%) and rest of argon such that the alloying elements of the metallic coating experience an intensive mixing with the weld metal in such a way that the alloy elements are finely divided from the weld metal after solidification. The weld pool dynamics is influenced as a process parameter by the protective gas. The steel is a thermoformable steel including boron-containing steel (22MnB5) or an air-hardening steel.