Small Punch Creep deformation and rupture behavior of 316L(N) stainless steel

The Small Punch Creep (SPC) behavior of 316L(N) stainless steel has been evaluated under various loads in the range 300-1000 N over a temperature range 898-973 K. The SPC curves clearly showed the transient, secondary and tertiary stages of creep. The transient creep deflection data have been analyzed on the basis of Garofalo's equation. The trend of variations of rate of exhaustion of transient creep deflection and steady state deflection rate with applied load revealed that the SPC deformation obeyed first-order reaction rate theory throughout the transient region. Using Chakrabarty's membrane stretch model, the creep strain-time curves were derived from deflection-time data measured in SPC tests. The steady state creep rate values calculated from such derived strain curves were closer to corresponding values obtained from conventional creep tests. From the load exponent of steady state deflection rate and estimated activation energy for creep, the mechanism that governs the SPC deformation of 316L(N) stainless steel under investigated conditions was found to be dislocation creep.