|
• EC • Season Cracking • Caustic Embrittlement • SCC • SSC • LME • HB-HE-HIC • Fatigue • Erosion • Fretting • Stray Current • Index |
|||
|
|
|||
Different Types of
Corrosion
|
|||
Caustic Embrittlement |
|||
|
Recognition |
|||
|
What is caustic embtittlement?
"Caustic embrittlement" was first used to describe the cracking of riveted mild steel boiler plates due to local deposition of concentrated hydroxide at temperatures of 200 to 250oC (400 to 480oF). It was later known as "stress corrosion cracking" which was in turn replaced by "environmental cracking". |
|||
| Mechanisms | |||
|
What causes caustic embrittlement? Caustic embrittlement results from the conjoint action of three components: (1) a susceptible material (carbon steel); (2) a specific chemical species (concentrated hydroxide) and (3) tensile stress (around the riveted holes). Caustic soda (NaOH) was added in small amounts to boiler water to prevent scaling but the presence of caustics (alkalis), usually concentrated in crevices around rivet heads and at hot spots, combined with the considerable fabrication stresses around rivet holes to caused cracking of the steel boiler shells and tube plates. |
|||
| Prevention | |||
How to prevent
caustic embrittlement? Caustic embrittlement can be prevented through:
|
|||
| For more details | |||
| More details on caustic
embrittlement are included in the following
corrosion short courses which you can take as in-house training courses, online
courses or distance
learning courses:
Corrosion and Its Prevention (5-day module) |
|||
| Home | Subject Index | Contact Us |
Copyright © 1995-2009. All rights reserved. |
||