INTERNATIONAL CONFERENCE ON HYDROGEN SAFETY S SEBASTIAN SPAIN
INTERNATIONAL CONFERENCE ON HYDROGEN SAFETY S. SEBASTIAN – SPAIN SEPTEMBER 11 -13 TH, 2007 Compatibility of Metallic Materials Hydrogen Review of the Present Knowledge with Hervé Barthélémy
Compatibility of Metallic Materials with Hydrogen – Review of the present knowledge 1. INTRODUCTION 2. REPORTED ACCIDENTS AND INCIDENTS ON HYDROGEN EQUIPMENT 3. TEST METHODS 4. PARAMETERS AFFECTING HYDROGEN EMBRITTLEMENT OF STEELS - Environment, Design and Material The world leader in industrial and medical gases 2
Compatibility of Metallic Materials with Hydrogen – Review of the present knowledge 5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 6. HYDROGEN ATTACK 7. CONCLUSION - RECOMMENDATION The world leader in industrial and medical gases 3
1. GENERALIT IES § Internal hydrogen embrittlement § External hydrogen embrittlement The world leader in industrial and medical gases 4
1. GENERALIT IES 1 - COMBINED STATE : Hydrogen attack 2 - IN METALLIC SOLUTION : Gaseous hydrogen embrittlement The world leader in industrial and medical gases 5
1. GENERALIT IES § Important parameter : THE TEMPERATURE T 200°C Hydrogen embrittlement T 200°C Hydrogen attack The world leader in industrial and medical gases 6
1. GENERALIT IES § Reversible phenomena § Transport of H 2 by the dislocations § H 2 traps CRITICAL CONCENTRATION AND DECOHESION ENERGY The world leader in industrial and medical gases 7
2. REPORTED ACCIDENTS 3. AND INCIDENTS FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1980 The world leader in industrial and medical gases 8
2. REPORTED ACCIDENTS 3. AND INCIDENTS FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1983. HYDROGEN CRACK INITIATED ON INTERNAL CORROSION PITS The world leader in industrial and medical gases 9
2. REPORTED ACCIDENTS 3. AND INCIDENTS HYDROGEN CYLINDER BURSTS INTERGRANULAR CRACK The world leader in industrial and medical gases 10
2. REPORTED ACCIDENTS 3. AND INCIDENTS VIOLENT RUPTURE OF A HYDROGEN STORAGE VESSEL The world leader in industrial and medical gases 11
2. REPORTED ACCIDENTS 3. AND INCIDENTS H 2 VESSEL. HYDROGEN CRACK ON STAINLESS STEEL PIPING The world leader in industrial and medical gases 12
3. TEST METHODS § Static (delayed rupture test) Constant strain rate § Dynamic Fatigue The world leader in industrial and medical gases 13
3. TEST METHODS § Fracture mechanic (CT, WOL, …) § Tensile test § Disk test § Other mechanical test (semi-finished products) § Test methods to evaluate hydrogen permeation and trapping The world leader in industrial and medical gases 14
3. TEST METHODS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Vessel head Specimen O-rings Vessel bottom Gas inlet – Gas outlet Torque shaft Load cell Instrumentation feed through Crack opening displacement gauge Knife Axis Load application Fracture mechanics test with WOL type specimen The world leader in industrial and medical gases 15
3. TEST METHODS Specimens for compact tension test The world leader in industrial and medical gases 16
3. TEST METHODS Air Liquide/CTE equipment to perform fracture mechanic test under HP hydrogen (up to 1 000 bar) The world leader in industrial and medical gases 17
3. TEST METHODS 10 -4 10 -5 10 -6 10 -7 10 -8 20 25 30 Influence of hydrogen pressure (300, 150, 100 and 50 bar) - Crack growth rate versus K curves The world leader in industrial and medical gases 18
3. TEST METHODS da mm/cycle d. N 10 -2 Influence of hydrogen pressure by British Steel 10 -3 10 -4 152 bar H 2 41 bar N 2 10 -5 10 20 X 165 bar 30 40 60 80 100 K, MPa Vm The world leader in industrial and medical gases 19
3. TEST METHODS Tensile specimen for hydrogen tests (hollow tensile specimen) (can also be performed with specimens cathodically charged or with tensile spencimens in a high pressure cell) The world leader in industrial and medical gases 20
3. TEST METHODS § I = (% RAN - % RAH) / % RAN I = Embrittlement index RAN = Reduction of area without H 2 RAH = Reduction of area with H 2 The world leader in industrial and medical gases 21
3. TEST METHODS Pseudo Elliptic Specimen Cell for delayed rupture test with Pseudo Elliptic Specimen The world leader in industrial and medical gases 22
3. TEST METHODS Inner notches with elongation measurement strip Tubular specimen for hydrogen assisted fatigue tests The world leader in industrial and medical gases 23
3. TEST METHODS 1. 2. 3. 4. 5. 6. 7. Upper flange Bolt Hole High-strength steel ring Disk O-ring seal Lower flange Gas inlet Disk testing method – Rupture cell for embedded disk-specimen The world leader in industrial and medical gases 24
3. TEST METHODS Example of a disk rupture test curve The world leader in industrial and medical gases 25
3. TEST METHODS I m (MPa) Hydrogen embrittlement indexes (I) of reference materials versus maximum wall stresses ( m) of the corresponding pressure vessels The world leader in industrial and medical gases 26
3. TEST METHODS Fatigue test - Principle The world leader in industrial and medical gases 27
3. TEST METHODS Fatigue test - Pressure cycle The world leader in industrial and medical gases 28
3. TEST METHODS n. N 2 n. H 2 6 Cr-Mo STEEL Pure H 2 + 300 ppm O 2 F 0. 07 Hertz 5 4 3 2 1 Delta P (MPa) 0 4 5 6 7 8 9 10 11 12 13 Fatigue tests, n. N 2 versus P curves n. H 2 The world leader in industrial and medical gases 29
3. TEST METHODS Fatigue test Principle to detect fatigue crack initiation The world leader in industrial and medical gases 30
TESTS CHARACTERISTICS Type of hydrogen embrittlement and transport mode LOCATION OF HYDROGEN TRANSPORT MODE External Dislocations External + Internal Diffusion + Dislocation Hollow tensile specimen test External Dislocations Fracture mechanics tests External Dislocations P. E. S. test External Dislocations Tubular specimen test External Dislocations Cathodic charging test External Diffusion TESTS Disk rupture test F % test The world leader in industrial and medical gases 31
TESTS CHARACTERISTICS Practical point of view SPECIMEN (Size-complexity) CELL (Size-complexity) Disk rupture test Small size and very simple Hydrogen compressor and high pressure vessel Tensile test Relatively small size Large size Tensile machine Fracture mechanics test Relatively large size and complex Very large size and complex Fatigue tensile machine for fatigue test only P. E. S. test Average size and very easy to take from a pipeline Average size -- Tubular specimen test Large size and complex No cell necessary Large hydrogen source at high pressure Cathodic charging test Small size and simple Small size and very simple Electrochemical equipment (potentiostat) TESTS COMPLEMENTARY EQUIPMENT NEEDED The world leader in industrial and medical gases 32
TESTS CHARACTERISTICS Interpretation of results TESTS SENSIBILITY PRACTICAL DATA TO PREDICT IN SERVICE PERFORMANCE POSSIBILITY OF RANKING MATERIALS SELECTION OF MATERIALS – EXISTING CRITERIA Fatigue life Disk rupture High sensitivity Possible Yes PHe/PH 2 Tensile test Good/Poor sensitivity Possible/Difficult Yes/No Treshold stress Fracture mechanics Good sensitivity Possible No, but maximum allowable KIH could be defined - KIH - Crack growth rate P. E. S. test Poor sensitivity Difficult No Tubular specimen test Good sensitivity Difficult No - KIH Cathodic charging Good sensitivity Possible but difficult in practice No Critical hydrogen concentration The world leader in industrial and medical gases 33
4. PARAMETERS AFFECTING 5. HYDROGEN EMBRITTLEMENT OF STEELS 4. 1. Environment 4. 2. Material 4. 3. Design and surface conditions The world leader in industrial and medical gases 34
4. 1. Environment or “operating conditions” § Hydrogen purity § Hydrogen pressure § Temperature § Stresses and strains § Time of exposure The world leader in industrial and medical gases 35
4. 1. Environment or “operating conditions” § Hydrogen purity Influence of oxygen contamination The world leader in industrial and medical gases 36
4. 1. Environment or “operating conditions” § Hydrogen purity Influence of H 2 S contamination The world leader in industrial and medical gases 37
4. 1. Environment or “operating conditions” § Hydrogen pressure Influence of H 2 S partial pressure for AISI 321 steel The world leader in industrial and medical gases 38
4. 1. Environment or “operating conditions” § Temperature Influence of temperature - Principle The world leader in industrial and medical gases 39
4. 1. Environment or “operating conditions” § Temperature Influence of temperature for some stainless steels The world leader in industrial and medical gases 40
4. 1. Environment or “operating conditions” § Hydrogen purity § Hydrogen pressure § Temperature § Stresses and strains § Time of exposure The world leader in industrial and medical gases 41
4. 2. Material § Microstructure § Chemical composition § Heat treatment and mechanical properties § Welding § Cold working § Inclusion The world leader in industrial and medical gases 42
4. 2. Material § Heat treatment and mechanical properties The world leader in industrial and medical gases 43
4. 2. Material § Welding Ferrite content 0% (No weld) 2. 5 % 8% 25 % Embrittlement index 1. 9 2. 0 4. 2 The world leader in industrial and medical gases 44
4. 2. Material § Microstructure § Chemical composition § Heat treatment and mechanical properties § Welding § Cold working § Inclusion The world leader in industrial and medical gases 45
4. 3. Design and surface conditions § Stress level § Stress concentration § Surface defects The world leader in industrial and medical gases 46
4. 3. Design and surface conditions § Stress concentration Crack initiation on a geometrical discontinuity The world leader in industrial and medical gases 47
4. 3. Design and surface conditions § Stress concentration Crack initiation on a geometrical discontinuity The world leader in industrial and medical gases 48
4. 3. Design and surface conditions § Surface defects FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1983. HYDROGEN CRACK INITIATED ON INTERNAL CORROSION PITS The world leader in industrial and medical gases 49
5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 1) All metallic materials present a certain 2) degree of sensitive to HE 2) Materials which can be used § Brass and copper alloys § Aluminium and aluminium alloys § Cu-Be The world leader in industrial and medical gases 50
5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 3) Materials known to be very sensitive to HE : § Ni and high Ni alloys § Ti and Ti alloys 4) Steels : HE sensitivity depend on exact 5) chemical composition, heat or mechanical 6) treatment, microstructure, impurities 7) and strength Non compatible material can be used at limited stress level The world leader in industrial and medical gases 51
6. HYDROGEN ATTACK Main parameters summarized on the « Nelson curves » : § Influence of P, T, Cr and Mo § Ti and W have also a beneficial effect § C, Al, Ni and Mn (excess) have a detrimental effect Other parameters : § Heat treatment § Stress level, welding procedure The world leader in industrial and medical gases 52
6. HYDROGEN ATTACK Legend : Surface decarburization Internal decarburization (Hydrogen attack) Nelson curves The world leader in industrial and medical gases 53
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. The world leader in industrial and medical gases 54
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : The world leader in industrial and medical gases 55
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : • The « scope » , i. e. the hydrogen pressure, the temperature and the hydrogen purity The world leader in industrial and medical gases 56
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : • The « scope » , i. e. the hydrogen pressure, the temperature and the hydrogen purity • The material, i. e. the mechanical properties, chemical composition and heat treatment The world leader in industrial and medical gases 57
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : • The « scope » , i. e. the hydrogen pressure, the temperature and the hydrogen purity • The material, i. e. the mechanical properties, chemical composition and heat treatment • The stress level of the equipment The world leader in industrial and medical gases 58
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : • The « scope » , i. e. the hydrogen pressure, the temperature and the hydrogen purity • The material, i. e. the mechanical properties, chemical composition and heat treatment • The stress level of the equipment • The surface defects and quality of finishing The world leader in industrial and medical gases 59
7. CONCLUSION - RECOMMENDATION 1) The influence of the different parameters shall be addressed. 2) To safely use materials in presence of 3) hydrogen, an internal specification shall 4) cover the following : • The « scope » , i. e. the hydrogen pressure, the temperature and the hydrogen purity • The material, i. e. the mechanical properties, chemical composition and heat treatment • The stress level of the equipment • The surface defects and quality of finishing • And the welding procedure, if any The world leader in industrial and medical gases 60
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