Ron Hock has written a book, 'The Perfect Edge', which mostly explains how to sharpen woodworking tools (chisels, plane blades, etc.). It also provides a good explanation of what is happening and how the type and metallurgic treatment of the steel effects the sharpening, including some micro graphs of edges with various treatments.
The crystallization of the metal has a significant effect on the sharpening. The grains (carbon, carbide, etc.) effect both how the edge wears and how it sharpens. For example the grain size of stainless steels tends to be greater than for some tool steels and therefore can not achieve as sharp an edge. As an edge wears, or is sharpened, the grains break off. Small grains leave the edge sharp, large grains leave a rough and duller edge.