Investigation on mechanical properties of P92 steel using ball indentation

Abstract

The effect of normalizing and tempering temperatures on mechanical properties of P92 steel has been investigated using tensile tests and ball indentation techniques (BI) at several test temperatures in the range of 300–923 K. A silicon nitride indenter having 0.762 mm diameter was used for BI testing. The material deformation behaviour underneath the indenter has been investigated by optical microscopy, scanning electron microscopy and profilometry. Strength of the material decreased and its tendency to form pile up increased for higher test and tempering temperatures. The effect of tempering temperature was more dominant than that of normalizing temperature over tensile properties of the steel. The decrease in yield and ultimate tensile strength with increase in tempering temperature has been attributed to increase in M 23 C precipitate size, lath width and dynamic recovery. The tensile properties obtained from BI technique were in good agreement with that obtained from conventional tensile tests.