Strengthening mechanism of S30432 austenitic heat-resistant steel

The microstructure of as-supplied, as-aged and as-crept S30432 at 650 degrees C (=923 K) was examined to study the strengthening mechanism, especially the precipitation behavior and the contribution of precipitated particles to the creep rupture strength were emphasized Results show that Nb(C,N) precipitates in the as-supplied microstructure, while aging and creep result in the precipitation of epsilon-Cu and M23C6 High creep rupture strength of S30432 steel is attributed to the precipitation hardening of epsilon-Cu, Nb(C,N) and M23C6 Extremely, epsilon-Cu plays an important role in improving the creep rupture strength of S30432, and at least 61% of the creep rupture strength of S30432 at 650 degrees C results from the precipitation hardening of epsilon-Cu particles