transgranular/intergranualr -----ing

[kevinr]

I have been having some trouble with small -----s using SAW on 50mm C-Mn steel, Material group 2.1.
A ----- has been cut out and ready to be sent to the materials lab.
I was wondering what is the difference between transgranular and intergranular -----ing and how can I test for this?

[fluence377]

Estimated friend, I think the following thing
A Transgranular fracture is a fracture that follows the edges of lattices in a granular material, ignoring the grains in the individual lattices. This results in a fairly smooth looking fracture with less sharp edges than one that follows the changing grains.
Think of several wooden jigsaw puzzle pieces with the grains showing, but with each piece having grains running in a different direction. A Transgranular fracture follows the grains in the wood, not the edges of the puzzle pieces.
An intergranular fracture is a fracture that follows the grains of the material. If the material has multiple lattice organizations, when one lattice ends and another begins, the fracture changes direction to follow the new grain. This results in a fairly jagged looking fracture with bumpy edges.
Intergranular fractures are -----s that take place along the grain boundary of a material. Straight edges of the grain and shiny surface may be seen. There are several processes that can lead to intergranular fracture.
• Microvoid nucleation and coalescence at inclusions or second phase particles located along grain boundaries
• Grain boundary ----- and cavity formation associated with elevated temperature stress rupture condition.
• Decohesion between contiguous grain due to presence of impurity at grain boundaries and in the presence of hydrogen and liquid metals.
• Stress corrosion -----ing associated with chemical dissolution along grain boundaries.
• Cyclic loading when the material insufficient numbers of independent slip systems to accommodate plastic deformation between contiguous grain leading to grain boundaries.

The test is the micrography