Klockner-werke Ag

Hans Kosmider

Ludwig Von Bogdandy

A compound steel material of high corrosion resistance is manufactured by alloying a carbon steel carrier material having a carbon content of at most 0.20C and of at least 0.04C with a carbide and nitride forming substance, compounding the alloyed carrier material with a ferritic chromium steel material of normal carbon content, followed by hot-rolling the compound steel material to a hot rolled strip or sheet which is then annealed at a temperature and for a time period sufficient for the carbon content of the ferritic chromium steel coating layer to be reduced to between 0.001 and 0.003% so as to increase the corrosion resistance of the chromium steel material to that of a superferritic material. After annealing, the sheet may be etched and surface-finished or cold-rolled, recrystallization annealed and thereafter surface-finished, such as temper-rolled. The ferritic chromium steel material has at most 0.1% of carbon prior to annealing. The carbide and nitride forming substance may be titanium whose content in the alloyed carrier material is preferably between 0.50% and 2.00%. The thickness of the ferritic chromium steel coating layer is between 50 and 500 .mu.m, the annealing temperature between 650.degree. and 900.degree. C., and the annealing time period between 8 and 72 hours.

Method of manufacturing a compound steel material of a high corrosion

Molten steel is killed by passing molten aluminum under pressure below the surface of the steel melt through a lance heated to the melting point of the aluminum.

Growing community of inventors

Munich, Georgia

Hans Kosmider