Abstract
Structural changes occurring during ageing of a nickel-1.8 at% carbon alloy have been followed by transmission electron microscopy. Rod-shaped nickel carbide formed in the temperature range of 400–600°C. The crystallography of the nickel carbide has been analysed. Spherical graphite precipitated by ageing at temperatures above 450°C. Both precipitates were associated with immense tangles of dislocations around them resulting mainly from the large difference in the diffusivities of interstitial carbon atoms and vacancies in the nickel matrix.
