Cold-Drawn Pearlitic Steels as Hierarchically Structured Materials: An Approach to Johann Sebastian Bach

摘要

This paper analyzes the hierarchical microstructure of cold-drawn pearlitic steels. To this end, environmentally assisted fracture behavior and microstructural integrity in aggressive environments is analyzed in progressively cold-drawn pearlitic steels based on their microstructural evolution during the multi-step cold drawing manufacture process producing a slenderizing and orientation of the pearlitic colonies (first microstructural level), and orientation and densification of the ferrite/cementite lamellae (second microstructural level). Thus the microstructure of the cold-drawn pearlitic steel wires becomes progressively oriented as the cold-drawing degree increases and this microstructural fact affects their macroscopic behavior, inducing anisotropic fracture behavior and crack path deflection in aggressive environments. In addition, the hierarchical microstructure of cold-drawn pearlitic steel wires in two microstructural levels (colonies and lamellae) suggests a consideration of them as hierarchically structured materials (HSM). Furthermore, an analogy is established in the paper between the microstructural arrangement in cold-drawn pearlitic steels and the multi-level structure of Johann Sebastian Bach's music.