The Influence of Annealing Temperatures on the Ductility and Toughness of Springs

ABSTRACT This study was carried out to investigate the influence of annealing temperatures on the ductility and impact toughness of springs. The springs were made from mild steel rod having a diameter of 6mm. The springs were then subjected to annealing process at temperatures of 650 o C, 700 o C, and 850 o C. The annealed springs were tested for ductility and impact toughness. The annealed spring became softer with increase in the annealing temperature; its percentage elongation, or ductility, increased from 18.75% to 30% and later 42.5 % with increase in annealing temperature. The impact toughness increased from 40 J to 45J and later to 49 J. The Rockwell hardness values however reduced from 30 RC to 23 RC and later 20 RC as annealing temperature increased