Crab graphite

Form of graphite with a compact flake-like and partly rugged appearance. Crab graphite is usually the temper carbon in annealed malleable cast iron (Fig. 1).

Degenerate nodular graphite GJS is also called crab or chunky graphite; it is caused by interfering elements in the iron, insufficient inoculation or low magnesium contents which may lead to Graphite degeneration.

  • Fig. 1: Malleable cast iron structure with crab graphite and incorporated manganese sulfides, 100:1, etched