Voestalpine Stahl Gmbh

Voestapline Stahl Gmbh

Helmut Spindler

Wolfgang Ernst

Markus Sonnleitner

Gerhard Hubmer

Martin Klein

The invention relates to a method for producing hot-rolled hot strip products in which a steel alloy is melted; the melted steel alloy is cast into slab ingots and after being heat-ed to a temperature above Ac3, the slab ingots are hot rolled until they reach a desired degree of deformation and a desired strip thickness; the rolling is performed above the recrystallization temperature of the alloy; after the rolling, the strip is cooled to room 10 temperature and for hardening purposes, is briefly heated to a temperature >Ac3 and cooled again, characterized in that the heating takes place with a temperature increase of more than 5 K/s, more than 10 K/s, more than 50 K/s, or more than 100 K/s and is kept at a desired target temperature for a period of 0.5 to 60 s before cooling to yield improved mechanical properties.

Method for producing conventionally hot-rolled profiled strip products

A method for producing thermomechanically produced hot strip products having improved mechanical properties is provided. A steel alloy is melted and adjusted so that a recrystallization during hot rolling at greater than 800° C. is suppressed. The melted steel alloy is cast into slab ingots and after being heated to a temperature above Ac, the slab ingots are hot rolled until they reach a desired degree of deformation and strip thickness. The strip is then cooled to room temperature and is hardened by briefly reheating to a temperature above Acand cooling again. The reheating takes place with a rapid temperature increase of more than 5 K/s and is maintained at the targeted temperature for a period of 0.5 to 60 seconds before cooling to yield the improved mechanical properties.

Method for producing thermo-mechanically produced profiled hot-rolled strip products

A method for producing an ultra-high-strength hot-rolled structural steel includes producing a steel alloy with a carbon content not greater than 0.2%, avoiding a diffusive transformation of the austenite by achieving a transformation delay through the addition of manganese, chromium, and boron, and casting the steel alloy. The cast steel alloy is heated and hot rolled to form a steel strip which is then immediately hardened and mechanically straightened to produce mobile dislocations, wherein the boron, manganese and chromium delay diffusive transformation from an austenite structure to achieve formation of a martensite structure during the hardening. The steel strip is then annealed at a temperature between 100 and 200° C.

Growing community of inventors

Oed-Öhling, Austria

Helmut Spindler