Hoesch Werke Aktiengesellschaft

Hoesch Aktiengesellschaft

Friedhelm Retzlaff

Heinz Gross

Rolf Krebs

Manfred Gerber

Friedrich Reith

Karl H Schlusnus

Hans-Jurgen Wahl

Otto Welsing

Friedhelm Gunter

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

Improved steel profiles having superior material characteristics are obtained by rolling a precipitation-hardenable fine grain steel, cooling it from a final rolling temperature above the A.sub.1 -temperature down to a temperature of about 400.degree. C. in an atmosphere in which it is allowed to overage, whereupon the steel plate or strip is then cooled down to room temperature and cold-processed to form an open profile which can thereupon be converted into a tube by welding together its longitudinally extending edges and which is then subjected to solution-annealing in order-to dissolve coarse precipitants and subsequently further cooled to form finely dispersed precipitants in the profile.

Method of making high strength steel tube

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

Improved steel profiles having superior material characteristics are obtained by rolling a precipitation-hardenable fine-grain steel, cooling it from a final rolling temperature above the A.sub.1 -temperature down to a temperature of about 400.degree. C. in an atmosphere in which it is allowed to overage, whereupon the steel plate or strip is then cooled down to room temperature and cold-processed to form an open profile [which can thereupon be converted into a tube by welding together its longitudinally extending edges and] which is then subjected to solution-annealing in order to dissolve coarse precipitants and subsequently further cooled to form finely dispersed precipitants in the profile.

Growing community of inventors

Kamen-Methler, Germany

Friedhelm Retzlaff