How does intergranular corrosion occur?
Intergranular corrosion (IGC) It is as a result of chromium depletion, mainly due to the precipitation of chromium carbides in the grain boundaries. Chromium carbides can be precipitated if the stainless steel is sensitized in the temperature range 550–850°C (1020–1560°F), for example during heat treatment or welding.
What happens during intergranular corrosion?
Intergranular corrosion occurs as the name indicates along grain boundaries on. This corrosion form is sensitive to high carbon contents in the stainless steel and occurs if chromium carbides are precipitated in between the grains. Precipitation reactions in stainless steels can be read about in Section 3.04.
What is intergranular corrosion example?
Stainless steels and weld decay sensitization are the best examples of intergranular corrosion. Grain boundaries that are rich in chromium elements will precipitate lead. This makes the boundaries very vulnerable to corrosion attacks in various electrolytes.
What is the most likely cause of intergranular corrosion?
A primary cause of intergranular corrosion is? improper heat treatment.
What type of corrosion is intergranular corrosion?
Intergranular corrosion (IGC), also known as intergranular attack (IGA), is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides. (Cf. transgranular corrosion.)
What is intergranular corrosion test?
Intergranular Corrosion (IGC) or Intergranular Attack (IGA), is an efficient test for screening a material’s corrosion resistance under certain conditions.
Where is intergranular corrosion found?
grain boundaries
Intergranular corrosion is localized attack along the grain boundaries, or immediately adjacent to grain boundaries, while the bulk of the grains remain largely unaffected.
How do you find intergranular corrosion?
Streicher Test (ASTM A262 Practice B) Generally used for stainless steel and nickel alloys, the Streicher test involves boiling the specimen in a Ferric Sulfate – Sulfuric Acid solution for 24-120 hours and evaluating the results. The level of corrosion is determined by mass loss.
What is an IGC test?
The procedure includes subjecting a specimen to a 24 to 120 hour boil in ferric sulfate – 50% sulfuric acid. This procedure measures the susceptibility of stainless steel and nickel alloys to inter granular attack associated with the precipitation of chromium carbides at grain boundaries.