1. Corrosion process and control (TKK-2289)
15/16 Semester genap
Corrosion process and control (TKK-2289)
Instructor: Rama Oktavian; Vivi Nurhadianty.
Office Hr.: T , Th ; 13-15, F ; 13-15

2. Corrosion types Hydrogen damage
embrittlement is not the only way in which materials are damaged by hydrogen. Steels are also damaged by hydrogen blistering at high temperatures
three categories of hydrogen damage:
a. High temperature hydrogen attack
b. Hydrogen blistering
c. Hydrogen embrittlement

3. Corrosion types
Hydrogen damage

4. Corrosion types
Hydrogen damage

5. Corrosion types Hydrogen damage High temperature hydrogen attack
requires the presence of atomic hydrogen
At temperatures above 230◦C
hydrogen partial pressure above 100 psi (7 kg/cm2)
atomic hydrogen reacts with the carbon component in the steel to form methane

6. Corrosion types Hydrogen damage
b. Hydrogen blistering (hydrogen induced cracking)
caused by the atomic hydrogen diffusing into a steel and being trapped at a non-metallic inclusion
a high pressure is localized at the inclusions or grain boundaries until the bulging occurs, producing blisters or cracks
Stepwise cracking occurs when short blisters at varying depths within the steel link together to form a series of steps

7. Corrosion types Hydrogen damage
b. Hydrogen blistering (hydrogen induced cracking)

8. Corrosion types Hydrogen damage
b. Hydrogen blistering (hydrogen induced cracking)
Condition for HIC to occur:
The presence of water phase
The presence of atomic hydrogen
An agent that retards the formation of molecular hydrogen at the surface
Presence of grain boundaries or inclusions
Maintenance of an active surface
Discontinuity in metal, such as slag, inclusion and/or void

9. Corrosion types Hydrogen damage
b. Hydrogen blistering (hydrogen induced cracking)
Source of hydrogen:
Surface treatment of metal
Hydrogen absorption from metal fabrication
Mechanism of hydrogen formation

10. Corrosion types Hydrogen damage c. Hydrogen embrittlement
Cathodic hydrogen is adsorbed on the surface as atomic hydrogen (reduced)
The internal pressure produced by the gaseous hydrogen is much lower than produced by cathodic hydrogen
occurs during the plastic deformation of alloys in contact with hydrogen gas

11. Corrosion types Hydrogen damage c. Hydrogen embrittlement Example:
In plating operations.
In pickling operations
In cleaning of high strength steels in chloride or fluoride solution
Manufacturing and fabrication processes
Materials that are most susceptible to hydrogen embrittlement:
Iron, titanium, zirconium, martensitic steels, high strength aluminum alloys.

12. Corrosion types Hydrogen damage c. Hydrogen embrittlement Example:
In plating operations.
In pickling operations
In cleaning of high strength steels in chloride or fluoride solution
Manufacturing and fabrication processes
Materials that are most susceptible to hydrogen embrittlement:
Iron, titanium, zirconium, martensitic steels, high strength aluminum alloys.

13. Corrosion types Hydrogen damage c. Hydrogen embrittlement
Different between SCC and Hydrogen embrittlement
SCC begins at the surface, whereas hydrogen embrittlement begins internally
The magnitude of corrosion is higher at the origin of SCC than observed with hydrogen embrittlement

14. Corrosion types Hydrogen damage c. Hydrogen embrittlement
Different between SCC and Hydrogen embrittlement

15. Corrosion types Hydrogen damage Important parameter : THE TEMPERATURE
c. Hydrogen embrittlement
Important parameter : THE TEMPERATURE
T  200°C Hydrogen embrittlement
T  200°C Hydrogen attack

16. FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1980
Corrosion types
Hydrogen damage
c. Hydrogen embrittlement
Example
FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1980

17. Corrosion types Hydrogen damage
FAILURE OF A HYDROGEN TRANSPORT VESSEL IN HYDROGEN CRACK INITIATED ON INTERNAL CORROSION PITS

18. Corrosion types
Hydrogen damage

19. Corrosion types
Hydrogen damage

20. Thank You !