Patenting

Specialized (generally continuous) annealing process, specifically for medium-carbon or high-carbon steel rod or wire before wiredrawing, or between drafts, to improve consistency of grain structure and tensile strength. This process is also done to reduce stresses from previous drawing (to allow further reduction without degradation of physical properties). The wire is heated above the austenitizing transformation temperature range of 815-982°C (1500-1800°F), held at temperature to assure complete transformation, then cooled in air or a controlled-temperature media of salt or lead below the equilibrium temperature at which austenite begins to form during heating.