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Boiler Corrosion

Galvanic Corrosion
Can occur due to Oxygen attack or contact of two dissimilar metals in an electrolyte (eg: Copper + Steel).

Oxygen Attack (Pitting Corrosion)
At the Anode:

Metal goes into solution               Fe ⟶ Fe2+ + 2 e-OXIDATION

At the Cathode:

Oxygen is reduced           ½ O2 + H2O + 2 e- ⟶ 2 OH- REDUCTION

The variables pH, temperature and the concentration of oxygen affect the rate of corrosion.
To avoid this alkaline conditions are maintained in the boiler.
Oxygen reacts with iron to give ferric oxide (rust) Fe2O3 which will not protect the metal from further attack and metal is continuously dissolved.

4Fe + 3O2 → 2 Fe2O3 Hematite (ferric oxide)

Oxygen corrosion is usually observed as localized pitting on a metal surface. (Pitting Corrosion)



This form of corrosion can be reduced by:

1.by reducing the level of oxygen as far as possible using mechanical means which include deaeration and/or judicious heating, coupled with good feed-system design (Cascade Tank)

by ensuring that t…

Boiler Scale Formation

CV Template

CV Template for Seafarers

Quotes for Success by Warren Buffet

IMO in the polar environment: the Polar Code explained

Polar Code

International Code for Ships Operating in Polar Waters

IMO has adopted the International Code for Ships Operating in Polar Waters (Polar Code) and related amendments to make it mandatory under both the  International Convention for the Safety of Life at Sea (SOLAS) and the International Convention for the Prevention of Pollution from Ships (MARPOL). The Polar Code entered into force on 1 January 2017. This marks an historic milestone in the Organization’s work to protect ships and people aboard them, both seafarers and passengers, in the harsh environment of the waters surrounding the two poles.
The Polar Code and SOLAS amendments were adopted during the 94th session of IMO’s Maritime Safety Committee (MSC), in November 2014; the environmental provisions and MARPOL amendments were adopted during the 68th session of the Marine Environment Protection Committee (MEPC) in May 2015.

MARPOL Annex VI

Regulations for the prevention of Air pollution from ships


Special Areas under MARPOL

In Annex I, Annex II, Annex IV and Annex V, MARPOL defines certain sea areas as "special areas" in which, for technical reasons relating to their oceanographical and ecological condition and to their sea traffic, the adoption of special mandatory methods for the prevention of sea pollution is required. Under the Convention, these special areas are provided with a higher level of protection than other areas of the sea.

Materials

MATERIALS
Properties of Materials

A General Cargo Ship at Sea

MARPOL Annex IV

MARPOL ANNEX IV
Regulations for prevention of pollution by sewage in ships