HEAT TREATMENT by voestalpine Wire Technology

For you as a customer, straightforward processing with low forming forces is of high relevance, holding open the option of multi-stage forming, perhaps even without intermediate heat treatment.

The challenge here is to provide material with low strength and high formability, or with forming properties that are tailored specifically to your needs, already with an eye on the desired technological properties of the final component.

Hot rolling of wire rod requires precise temperature control starting in the steelworks with optimized chemical compositions, in the walking beam furnace, during necessary intermediate heating steps, in the management of the rolling heat, or in the precise temperature setting for thermomechanical rolling. By this, we create the conditions for low decarburization, for ideal grain sizes, or for already pre-set properties by TM rolling.

Tightly focused cooling sets many properties of our wire rods. The laying temperature necessary for scale, grain sizes and the correct metallurgical structure is already defined in the water cooling section.

Diameters less than 23 mm end up on the Stelmor conveyor belt, an air-cooled cooling section, where we ensure that wire rods do not show any undesired microstructural elements. Precisely adjusted pearlite structures are just as much a part of our process standard as cooling curves, which follow precisely the requirements of time-temperature transformation diagrams of your steels. This requires knowledgeable setting adjustments for fans, flaps, lids, radiation shields along the Stelmor line, and perhaps the use of the active auxiliary heating for challenging properties.

Pot cooling also gives us the option of completed bainitic transformations directly from the rolling heat. You can find our bainitic solutions in high-strength screws, seismic anchors, or special solutions in the field of hydrogen applications.

Larger diameters are water-cooled on the Garrett line. The combination of water cooling and the use of residual heat in the wire rod coil results in the metallurgical structure you desire.

Sometimes final adjustments in the structure are still required, because rolled or drawn structures are not always the method of choice. In such cases, we adjust the metallurgical structure to your needs. This can be simple stress relief annealing or tempering, soft annealing or annealing to a certain hardness, annealing for spherical cementite or patenting in a lead bath, diffusion annealing for controlled reduction of segregation effects or finalization of the surface treatment.

Customer orientation, quick and knowledgeable reaction to your requirements, flexibility and innovation are just some of the factors that have a decisive influence on our wire production and processing. By this, we can make a difference for our customers.