Process for the butt-welding of especially deep-drawable steel sheets or steel strips galvanized at least on one side

US4650954A · kind A · utility

Assignee

• Thyssen Stahl AG · DE

Inventors

• Adam Frings · Essen, DE
• Wilfried Prange · Dinslaken, DE

Key dates

• Filing date: Jan 21, 1986
• Grant date: Mar 17, 1987
• Expiry date: Jan 21, 2006

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23K2103/50
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A process for the butt-welding of especially deep-drawable steel sheets or steel strips galvanized at least on one side, in which the welding seam is protected against corrosion. To obtain a welding seam flush with the sheet and protected against corrosion, without the reworking of the welding seam and without the use of filler material, sheets or strips having essentially rectangular cut edges with a corrosion in the longitudinal direction of at most 0.4 mm are used. The sheets and strips brought into touch contact with these cut edges are melted in the region of the welding joint by means of a laser beam, of which the focal spot covering the cut edges has a diameter of at most 0.2 mm. Because of the extremely narrow welding gap, the voids are filled by the molten material of the adjacent sheets, without any detectable reduction in the thickness of the sheets or strips. Furthermore, the welding seam is protected against corrosion as a result of the long-range protection effect exerted by the zinc of the adjacent regions.