THE EFFECTS OF HEAT TREATMENTS ON THE HARDNESS AND TENSILE PROPERTIES OF COLD ROLLED IODIDE HAFNIUM

摘要

This report describes the effects of heat treatments on the hardness and tensile properties of cold rolled hafnium. EquatLons and curves for predicting hardness after various times at temperatures of 750, 800, and 850 C (1382, 1472, and 1562 F) for cold reductions up to 25 percent in 5-percent incre-ments are presented. Other curves are provided which estimate annealing times at temperatures greater than 850 C (1562 F) and up to 950 C (1742 F). The experimental data were utilized to estimate activation energies for the annealing process.nEquations and curves were established to relate tensile properties to the amount of cold reduction and the testing temperature. Graphs were made of the effects of heat treatments for 1/2 or 24 hours at 700, 800, 900, 1000, and 1100 C (1292, 1472, 1652, 1832, and 2012 F) on the tensile properties at room temperature and 316 C (600 F). The data revealed a decrease in ductility as measured by percent elongation and percent reduction of área when heat treatments greater than 900 C (1652 F) were employed. No corresponding change in yield or ultímate tensile strength valúes was noted at these temperatures.