Hoesch Werke Aktiengesellschaft

Hoesch Aktiengesellschaft

Rolf Krebs

Heinz Gross

Friedhelm Retzlaff

Manfred Gerber

Hans-Jurgen Wahl

Wilfried Kliesch

Peter Schorr

Friedrich-Otto Koch

Hans J Wahl

Heinz Strauch, Deceased

Friedrich O Koch

Heinz Strauch

Friedhelm Gunter

Otto Welsing

Method and apparatus for the continuous industrial production of tubular bodies in which coated or uncoated steel strip is formed to a slit tube and the opposite strip edges are longitudinally seam welded at high speed by a laser beam of high energy density under protective gas with or without supply of additive material, and after a preparation adapted to the narrow melt zone and bringing together of the strip edges a fusion welding with subsequent controlled cooling and upsetting is carried out which results in a seam geometry suitable for any further processing.

Method and apparatus for continuous production of tubular bodies by

A laser welding process is used according to the invention for the manufacture of a straight seam weld for tubular construction parts of ferritic, Ti-stabilized CR steel x5CrTi12 for exhaust systems in automobiles. This has the advantage that after welding the construction parts can be expanded or compressed by more than 40% of their original dimensions.

Use of the laser welding process for and method of manufacturing of

It is necessary to determine welding temperature as precisely as possible in order to properly control the high-frequency welding of longitudinal pipes. Changes in welding temperature are proportional to alterations in the welding current that flows through the edges of the skelp. Magnetic-field sensors can be used to directly and precisely determine alterations in the current and hence changes in the temperature. Voltages induced in the sensors can be processed into setting signals to correct the high-frequency welding generator and disruptions in the current used to generate signals to mark the site of failure on the pipe for subsequent rejection.

Method of and device for monitoring and/or controlling welding current

It is necessary to determine the effects of welding pressure in order to control the high-frequency welding process in the manufacture of pipes with longitudinal seams. It has been discovered that measurements of the height of the welding bead provide an approximation that is satisfactory for determining the mass of the bead, which is proportional to welding pressure in known pipe geometry. The height of the bead is transmitted by an optical system to the diode matrix of a commercially available diode-matrix camera. The results are processed to control welding pressure.

Method and device for controlling the welding process in the

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Hamm, Germany

Rolf Krebs