A "fish-eye" fracture feature was noted, and this would be indicative of hydrogen damage if the fracture was
intergranular. It's been reported the occurrence of hydrogen induced inter-granular or transgranular quasi-cleavage fracture largely depends on tramp element (P, Sb, Sn, As) segregation to grain boundaries and the subsequent loss of grain boundary cohesive strength.
Another close relative of
intergranular corrosion is stress corrosion cracking.
The different porosity types on the basis of petrography includes intragranular,
intergranular, moldic, vuggy and fractured porosity.
The 8 forms are (1) Uniform or general attack (2) Galvanic or two-metal corrosion (3) Crevice corrosion (4) Pitting corrosion (5)
Intergranular erosion (6) Selective leaching or parting (7) Erosion Corrosion and (8) Stress Corrosion.
The main hypotheses postulate, first, that the beds result from a process termed
intergranular corrosion (Cilek et al., 1995) or, second, that they result from processes relating to the formation of carbonate soils (Suchy, 2002).
The keynote address discusses the diffraction methods and scale transition model used to study the evolution of
intergranular stress and micro-damage phenomenon during elasto-plastic deformation.
Quartz cement, which ranges in average abundance from 0.9% to 1% (average of 1%) in Chang71 and mainly 0.8%~1.4% (average of 1.1%) in Chang72, occurs as either euhedral quartz crystals that fill
intergranular or dissolution pores or as syntaxial overgrowths around quartz grains.
Characteristically there is an initiation of crack at the surface of the metal, which may propagate either along grain boundaries (
intergranular) or between specific crystallographic planes (cleavage), due to stress concentration at the base of the crack.20