Deformation mechanisms that explain the combination of high plasticity and strength in steels wires with extreme carbon content

E. BRANDALEZE; M. AVALOS; M. ROMANYUK

Advanced Materials Proceedings

VBRI Sverige AB

Lugar: Linkoping; Año: 2018 vol. 3 p. 344 - 350

2002-4428

The alloy design concepts of high performance steels, involve the knowledge on the stability of carbides associated with nanoscale phenomena present in the structure as result of the deformation suffered during the thermomechanical processes. The understanding of the nanoscale phenomena open new frontiers to understand mechanical behaviours in the steel, not totally clarified until now. The paper discuss the structure evolution during wire drawing of pearlitic steels and the impact of cementite stability on different nanoscale structure phenomena, which explain the specific mechanical behaviour to achieveultra-high strength. Results on the kinetic and stability of carbides predicted on the base of thermodynamic simulation are correlated with thermal analysis tests results (dilatometry and differential scanning calorimetry) carried out by different authors in order to understand the cementite (Fe3C) dissolution during plastic deformation. In addition, information obtainedby traditional and no traditional microscopy techniques and X ray diffraction complete the study and allows to understand more deeply the structure evolution, including nanoscale phenomena that justify the mechanical behaviour during wiredrawing and the final strength level. The dislocation substructure evolution together with the cementite dissolutionduring sever plastic deformation which leads to a steadily increase of the strain hardening is clarified