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Short presentation about the hydrogen embrittlement of steels.What is it?Why is it a topical issue?How to study it?
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Hydrogen Embrittlement of Steel
Gaël GUETARD 1Gaël GUETARD
English presentation - 16/02/12Tutor : David DELAFOSSE
Summary
2
What is the « hydrogen embrittlement » ?
How does it work ? What are the risks ?
Why is it a topical issue?
What is hydrogen used for? What will it be used for?
How to study the « hydrogen embrittlement » ?
What is the experimental setup ?What do we measure?
3
Fe (140pm)
H (25 pm)
C (70 pm)
Comparison of radii
Why is the hydrogen corrosion so special ?
Hydrogen diffusion (1)
Mobility in α-iron at 20°C :
1 mm/min
4
Hydrogen diffusion (2)
FLUID METAL AIR
H H H H H H
diffusion
adsorption
absorption desorptio
n
sorption
Perfect Crystals
5
V
vacancies
dislocations
grain boundaries
precipitates
cavities
interphases
Hydrogen trapping (1)
6
Hydrogen trapping (2)
Hydrogen in grain boundaries an in the
pearlitic phase
Hydrogen on a manganese sulfide in a ferritic steel
Sources: Ohmisawa 2003 / Otsuka 2007
7
Hydrogen embrittlement
H
HH
H
HH
H2 H2H2
a loss in ductility a loss load carrying ability cracking (usually as sub-microscopic
cracks) catastrophic brittle failures
Recombination in H2
It can cause :
World production :
50 million
metric ton per yearFertilizer
Hydrocracking
8
Increasing demand of hydrogen for actual uses
Why do we need to improve steel resistance to hydrogen embrittlement ?
pro
babili
ty
10 % growth each year
9
Increasing demand of hydrogen for actual uses
Why do we need to improve steel resistance to hydrogen embrittlement ?
Oil extraction in harsher conditions
pro
babili
ty
Less accessible ressources
+An increasing
demand=
Harsher extraction conditions
High hydrogen sulfid concentration
10
Increasing demand of hydrogen for actual uses
Why do we need to improve steel resistance to hydrogen embrittlement ?
Oil extraction in harsher conditions
Storage and transport of renewable energiesp
robabili
ty
Discontinous energy production
Hydrogen can be a good way to store and
transport it
11
Increasing demand of hydrogen for actual uses
Why do we need to improve steel resistance to hydrogen embrittlement ?
Oil extraction in harsher conditions
Development of the “Hydrogen Economy”
Storage and transport of renewable energiesp
robabili
ty
Alternative economy based on hydrogen instead of oil
12
Increasing demand of hydrogen for actual uses
Why do we need to improve steel resistance to hydrogen embrittlement ?
Oil extraction in harsher conditions
Development of the “Hydrogen Economy”
Storage and transport of renewable energiesp
robabili
ty • More resistant steel (for a given price)
• Cheaper steel (for a given resistance)
• Steel that requires less maintenance
13
Example
What is the price for a 1%wt decrease of Nickel in a pipeline ?
P=20$/kg
PriceLengthSection Density
D=1me=2cm
L=10km ρ=8kg/L
=$ 2,000,000
x x x
14
My Research Project
Traction and Permeation tests
Sources: Moro 2007
15
My Research Project
Better understanding of the embrittlement mecanisms:
Trapping Mechanical properties
TrappingMicrostructure
Thanks for your attention
Questions ?
16