Caustic embrittlement, Chemistry

Assignment Help:

Caustic Embrittlement: Caustic embrittlement is a type of boiler corrosion caused by using highly alkaline water in the boiler. During softening process by lime-soda processes, free Na2CO3 is usually present in small proportion in the softening of water. In high pressure boilers, Na2CO3 decomposes to give sodium hydroxide and carbon-dioxide.

  Na2CO3 + H2O = 2NaOH + CO2

And this makes boiler water "Caustic". The NaOH containing water flows into the minute hair cracks, always present in the inner side of boiler, by capillary action. Here water evaporated and the dissolved caustic soda concentration increases progressively. This caustic soda attacks the surrounding area, thereby dissolving iron of boiler as sodium ferrate. This causes embrittlement of boiler parts, causing even failure of the boiler. Caustic cracking can be explained by considering the following concentration cell. The iron surrounded by the dilute NaOH becomes the cathodes sides, which the iron in contact with concentrated NaOH becomes anodic part, which is consequently dissolved or corroded.

 

 


Related Discussions:- Caustic embrittlement

Compounds, A table of how compounds are classified

A table of how compounds are classified

Co2 is isostructural with, Co2 is isostructural with: (1) SnCl 2       ...

Co2 is isostructural with: (1) SnCl 2                             (2) So 2      (3 ) HgCl 2                              (4) All the above ans: HgCl 2

Explain the triene, The triene contains two diene units with one double bon...

The triene contains two diene units with one double bond common to both. The dienophile reacts with the diene unit that is locked in an s-cis conformation.

Calculation of the power generated by a wind turbine, Calculation of the po...

Calculation of the power generated by a wind turbine: A wind turbine power curve is represented in a simplified manner by: C p is the conversion rate of the turbine:

Infrared spectroscopy, how we determine the compound is ir active or not . ...

how we determine the compound is ir active or not . and how we determine the polarity of a compound?

Organic chemistry, explain diversity and magnitude of organic compounds?

explain diversity and magnitude of organic compounds?

Soaps and detergents, Soaps and detergents Sodium and pottasium salts of...

Soaps and detergents Sodium and pottasium salts of fatty acids such as palmitic acid, stearic acid, oleic acid etc are called soaps, while detergents are ammonium or sulphonate

Nitric Acid, How does nitric acid reacts with metals in different concentra...

How does nitric acid reacts with metals in different concentrations?

Formula of a metallic oxide is mo, Formula of a metallic oxide is MO.The  f...

Formula of a metallic oxide is MO.The  formula of its phosphate will be: (1) M 2 (PO 4 ) 2                      (2) M (PO 4 )         (3) M 2 (PO 4 )       (4) M 3 (P

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd