Introduction to Corrosion

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Introduction to Corrosion

• Lecture01

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Definition

• Corrosion may be defined as the destruction of a
  metal or an alloy because of chemical or
  electrochemical reaction with its surrounding
  environment or medium

a metal or an alloy
environment or medium
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Environments in Corrosion1
1Sheir, L.L., R.A. Jarman, and G.T. Burstein,
eds. Corrosion. 3rd ed. Vol. 1. 2000,
Butterworth-Heinemann Oxford.
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Corrosion Metallurgy in Reverse2
2Fontana, M.G., Corrosion Engineering. 3rd ed.
1986, New York McGraw-Hill.
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Some Corrosion Failure Examples3
3Corrosion Doctors Website. Homepage
http//www.corrosion-doctors.org
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Aloha Incident
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Aloha Incident (Contd..)
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Bhopal Accident
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Carlsbad Pipeline Explosion
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Flow Accelerated Corrosion
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Nuclear Reactor with a Hole in the Head
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Losses due to Corrosion4
4Uhlig, H.H. and R.W. Revie, Corrosion and
Corrosion Control. 3rd ed. 1985, New York John
Wiley Sons.
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Cost of Corrosion

• Which cost more?
• Corrosion
• Fire
• Flooding
• Earthquake

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Cost of Corrosion(2004) in billion US5
Country Direct Cost Indirect Cost
USA 303.76 200 (approximately)
Japan 59.02
Former USSR 55.01
Germany 49.26
UK 8.51
Australia 7.32
Belgium 6.75
India 3.78
Poland 3.53
Canada 3.38
.....
.....
.....
Global 510.14 940 (approximately)
5Bhaskaran, R., N. Palaniswamy, and N.S.
Rengaswamy, Global Cost of CorrosionA Historical
Review, in Corrosion Materials, Vol 13B, ASM
Handbook. 2005, ASM International.
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Example of Overdesign3

• An 8" in. dia oil pipeline 225 miles long with a
  in. wall thickness was installed with no
  corrosion protection system
• With appropriate protection namely cathodic
  protection, it would have a thin wall thickness
  which would
• save 3,700 tons of steel (worth more than one
  million dollar)
• increase internal capacity of the pipeline by
  about 5.

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SoWhy Study Corrosion?

• Materials are precious resources
• Engineering design is incomplete without
  knowledge of corrosion
• Applying knowledge of corrosion protection can
  minimize disasters
• Corrosion contaminate products such as
  pharmaceutical, food and dairy products or luxury
  items like soap
• Corrosion products threat to the environment
• Artificial implants for the human body!!!

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Distribution of disciplines in which active
corrosion engineers have graduated
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So .. What would be expected from You (a
Corrosion Engineer)?

• Ensuring maximum life of new equipment
• Preservation of existing equipment
• Protecting or improving the quality of a product
  in order to maintain or improve a competitive
  position.
• Avoiding costly interruptions of production.
• Reducing or eliminating losses of valuable
  products by spillage or leaks.
• Refitting of equipment withdrawn from service
  because of corrosion.
• Reducing hazards to life and property that might
  be associated with corrosion
• Explosions of pressure vessels or piping systems
• release of poisonous or explosive gases or vapors
  
• are a few examples.