Innovative Annealing Technologies for Wire Rod and Drawn Wire: A Focus on Efficiency, Quality and Sustainability

Hot-rolled and Stelmore-cooled wire rod is an essential raw material for numerous cold-forming processes. The initial heat treatment is usually performed as spheroidize annealing to specifically adjust the cast and hot-rolled microstructure for subsequent cold-forming stages. Precise control of temperature profiles and process atmosphere composition is critical.

Excellent temperature uniformity, such as that achieved in HICON/H2 ® bell-type furnaces, is crucial for the successful annealing of wire coils, especially for high-alloy steels heat-treated above the Ac1-temperature. Thanks to high heat transfer coefficients, the necessary transformation energy reaches even the center of compact wire coils. The Result: Both outer and inner windings exhibit nearly identical temperature profiles, leading to extremely homogeneous mechanical properties. Due to a specialized design focused on maximum temperature homogeneity, the temperature difference between the hottest and coldest points in the charge stack is typically less than 10 K, even with large charge diameters and weights. High heat transfer rates are achieved through dedicated atmosphere recirculation (up to 50 m³/s) and optimized flow guidance within the workbase.