• D V V SATYANARAYANA

Articles written in Bulletin of Materials Science

• Effect of gamma prime depletion on creep behaviour of a nickel base superalloy (Inconel alloy X-750)

Specimens of a nickel base superalloy were exposed to air at 1423 K to study the effect of gamma prime depletion in the near-surface region on the creep behaviour of the alloy. The results showed that the gamma prime depletion in the air-exposed specimens caused a weakening effect, leading to enhanced creep rate. Kachanov’s damage parameterf was determined and was found to be 0·5 indicating that the near-surface region, comprising of surface oxide, grain boundary oxide and gamma prime depleted region, carried a small fraction of the applied stress. It is further shown that the damaging effect is more pronounced in thinner specimens.

• Evolution of microstructure with increasing carbon content and its effect on mechanical properties of disordered iron–aluminium alloy

Correlation of microstructure and mechanical properties of hot-rolled Fe–7 wt.% Al with varying carbon contents has been investigated in detail. The microstructures of the alloys change significantly with an increase in the carboncontent. An alloy with 0.012 wt.% carbon shows a single ferrite phase, whereas with increase in carbon up to 0.65 wt.%, the microstructure evolves into a dual phase consisting of ferrite and $\kappa$-pearlite. At about 1.5 wt.% carbon, the alloy exhibits only $\kappa$-pearlite and with a further increase in carbon to 2.2 wt.%, an additional phase starts precipitating in the form of graphite. The room temperature tensile strength of the alloy increased significantly with an increase in the carbon content, which is in agreement with the microstructure. The yield strength and hardness of the steels with different carbon contents can becorrelated well with the inter-barrier spacing in different steels.

• # Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019