Measurement of High Temperature Elastic Moduli of an 18Cr-9Ni-2.95 Cu-0.58 Nb-0.1C (Wt %) Austenitic Stainless Steel

The Young's modulus (E) and Shear modulus (G) of an indigenously developed 18Cr-9Ni-0.1C-2.95 Cu-0.58Nb (wt %) austenitic stainless steel has been evaluated in the temperature range 298 K to 1273 K (25 degrees C to 1000 degrees C), using Impulse excitation technique (IET). The Bulk modulus (K) and the poison's ratio have been estimated from the measured values of E and G. It is observed that the elastic constants (E, G and K) are found to decrease in a nonlinear fashion with increase in temperature. The Cu precipitation is found to influence the elastic moduli of the steel in the cooling cycle. The observed elastic moduli are fitted to 3rd order polynomial equations in order to describe the temperature dependence of E, G, K moduli in the temperature range 298-1273 K (25 degrees C to 1000 degrees C). The room temperature values of E,G and K moduli is found to be 207, 82 and 145 GPa respectively for the present steel.