Okuzeka
Chemical Engineering vocabulary · Materials and Corrosion

Pitting

Meaning in chemical engineering, with examples

/ˈpɪtɪŋ/nounAdvanced term

In chemical engineering, pitting means: A form of local corrosion that creates small, deep holes in a metal surface while the area around them looks almost undamaged.

In Turkish: çukurcuk korozyonu, oyuklanma, pitting korozyonu

How it is used

Typical of stainless steels in chloride service and of stagnant water. It is dangerous because a few deep pits can cause a leak even when overall wall loss is small. Inspectors report pit depth, and engineers compare grades using a pitting resistance number (PREN).

Example sentences

  1. The exchanger tubes leaked after only two years because of pitting under deposits.

  2. Duplex steel has much better pitting resistance than 304 in seawater.

Common collocations

  • pitting corrosion
  • pitting resistance
  • pit depth
  • under-deposit pitting
  • corrosionThe slow damage of a metal by chemical or electrochemical reaction with its surroundings, such as rust on carbon steel or attack by acids and chlorides.
  • stainless steelA family of steels containing at least about 10.5% chromium, which forms a thin protective oxide layer and gives much better corrosion resistance than carbon steel.
  • corrosion allowanceExtra wall thickness added to a vessel or pipe on top of what strength calculations require, so that it can lose metal to corrosion over its life and still be safe.
  • material of constructionThe material that a piece of equipment, pipe or part is made from, chosen for strength, temperature, corrosion resistance and cost.

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: