1. INTERNATIONAL CONFERENCE ON HYDROGEN SAFETY S. SEBASTIAN – SPAIN SEPTEMBER 11-13 TH, 2007 Hervé Barthélémy Compatibility of Metallic Materials with Hydrogen Review of the Present Knowledge

2. The world leader in industrial and medical gases 2 1. INTRODUCTION 2. REPORTED ACCIDENTS AND INCIDENTS ON HYDROGEN EQUIPMENT 3. TEST METHODS Compatibility of Metallic Materials with Hydrogen – Review of the present knowledge 4. PARAMETERS AFFECTING HYDROGEN EMBRITTLEMENT OF STEELS - Environment, Design and Material

3. The world leader in industrial and medical gases 3 Compatibility of Metallic Materials with Hydrogen – Review of the present knowledge 5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 7. CONCLUSION - RECOMMENDATION 6. HYDROGEN ATTACK

4. The world leader in industrial and medical gases 4  Internal hydrogen embrittlement  External hydrogen embrittlement 1. GENERALITIES

5. The world leader in industrial and medical gases 5 2 - IN METALLIC SOLUTION : 1. GENERALITIES Hydrogen attack Gaseous hydrogen embrittlement 1 - COMBINED STATE :

6. The world leader in industrial and medical gases 6 T  200°CHydrogen embrittlement  Important parameter : THE TEMPERATURE 1. GENERALITIES T  200°C Hydrogen attack

7. The world leader in industrial and medical gases 7  Reversible phenomena  Transport of H 2 by the dislocations CRITICAL CONCENTRATION AND DECOHESION ENERGY 1. GENERALITIES  H 2 traps

8. The world leader in industrial and medical gases 8 FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1980 2. REPORTED ACCIDENTS AND INCIDENTS

9. The world leader in industrial and medical gases 9 FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1983. HYDROGEN CRACK INITIATED ON INTERNAL CORROSION PITS 2. REPORTED ACCIDENTS AND INCIDENTS

10. The world leader in industrial and medical gases 10 HYDROGEN CYLINDER BURSTS INTERGRANULAR CRACK 2. REPORTED ACCIDENTS AND INCIDENTS

11. The world leader in industrial and medical gases 11 VIOLENT RUPTURE OF A HYDROGEN STORAGE VESSEL 2. REPORTED ACCIDENTS AND INCIDENTS

12. The world leader in industrial and medical gases 12 H2 VESSEL. HYDROGEN CRACK ON STAINLESS STEEL PIPING 2. REPORTED ACCIDENTS AND INCIDENTS

13. The world leader in industrial and medical gases 13  Static (delayed rupture test) 3. TEST METHODS Constant strain rate Fatigue  Dynamic

14. The world leader in industrial and medical gases 14 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

15. The world leader in industrial and medical gases 15 3. TEST METHODS Fracture mechanics test with WOL type specimen 1.Vessel head 2.Specimen 3.O-rings 4.Vessel bottom 5.Gas inlet – Gas outlet 6.Torque shaft 7.Load cell 8.Instrumentation feed through 9.Crack opening displacement gauge 10.Knife 11.Axis 12.Load application

16. The world leader in industrial and medical gases 16 Specimens for compact tension test 3. TEST METHODS

17. The world leader in industrial and medical gases 17 3. TEST METHODS Air Liquide/CTE equipment to perform fracture mechanic test under HP hydrogen (up to 1 000 bar)

18. The world leader in industrial and medical gases 18 3. TEST METHODS Influence of hydrogen pressure (300, 150, 100 and 50 bar) - Crack growth rate versus K curves 10 -4 10 -5 10 -6 10 -7 10 -8 20 25 30

19. The world leader in industrial and medical gases 19 3. TEST METHODS X 152 bar 41 bar 1 bar 165 bar H2H2 N2N2 K, MPa Vm Influence of hydrogen pressure by British Steel 10 -2 10 -3 10 -4 10 -5 10 20 3040 6080100 da dN mm/cycle

20. The world leader in industrial and medical gases 20 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) 3. TEST METHODS

21. The world leader in industrial and medical gases 21  I = (% RA N - % RA H ) / % RA N I = Embrittlement index RA N = Reduction of area without H 2 RA H = Reduction of area with H 2 3. TEST METHODS

22. The world leader in industrial and medical gases 22 3. TEST METHODS Cell for delayed rupture test with Pseudo Elliptic Specimen Pseudo Elliptic Specimen

23. The world leader in industrial and medical gases 23 3. TEST METHODS Tubular specimen for hydrogen assisted fatigue tests Inner notches with elongation measurement strip

24. The world leader in industrial and medical gases 24 Disk testing method – Rupture cell for embedded disk-specimen 1.Upper flange 2.Bolt Hole 3.High-strength steel ring 4.Disk 5.O-ring seal 6.Lower flange 7.Gas inlet 3. TEST METHODS

25. The world leader in industrial and medical gases 25 Example of a disk rupture test curve 3. TEST METHODS

26. The world leader in industrial and medical gases 26 Hydrogen embrittlement indexes ( I ) of reference materials versus maximum wall stresses (  m) of the corresponding pressure vessels  m (MPa) I 3. TEST METHODS

27. The world leader in industrial and medical gases 27 Fatigue test - Principle 3. TEST METHODS

28. The world leader in industrial and medical gases 28 Fatigue test - Pressure cycle 3. TEST METHODS

29. The world leader in industrial and medical gases 29 Fatigue tests, versus  P curves nN 2 nH 2 0 1 2 3 4 5 6 45678910111213 Delta P (MPa) Cr-Mo STEEL Pure H 2 H 2 + 300 ppm O 2 F 0.07 Hertz nN 2 nH 2 3. TEST METHODS

30. The world leader in industrial and medical gases 30 Fatigue test Principle to detect fatigue crack initiation 3. TEST METHODS

31. The world leader in industrial and medical gases 31 Type of hydrogen embrittlement and transport mode TESTS LOCATION OF HYDROGEN TRANSPORT MODE Disk rupture testExternalDislocations F % testExternal + InternalDiffusion + Dislocation Hollow tensile specimen test ExternalDislocations Fracture mechanics tests ExternalDislocations P.E.S. testExternalDislocations Tubular specimen test ExternalDislocations Cathodic charging test ExternalDiffusion TESTS CHARACTERISTICS

32. The world leader in industrial and medical gases 32 Practical point of view TESTS SPECIMEN (Size-complexity) CELL (Size-complexity) COMPLEMENTARY EQUIPMENT NEEDED Disk rupture test Small size and very simple Hydrogen compressor and high pressure vessel Tensile test Relatively small size Large sizeTensile 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 CHARACTERISTICS

33. The world leader in industrial and medical gases 33 Interpretation of results TESTS TESTS SENSIBILITY POSSIBILITY OF RANKING MATERIALS SELECTION OF MATERIALS – EXISTING CRITERIA PRACTICAL DATA TO PREDICT IN SERVICE PERFORMANCE Disk ruptureHigh sensitivityPossible Yes P H e/P H2 Fatigue life Tensile test Good/Poor sensitivity Possible/DifficultYes/NoTreshold stress Fracture mechanics Good sensitivity Possible No, but maximum allowable K IH could be defined - K IH - Crack growth rate P.E.S. testPoor sensitivityDifficultNo Tubular specimen test Good sensitivity DifficultNo- K IH Cathodic charging Good sensitivity Possible but difficult in practice No Critical hydrogen concentration TESTS CHARACTERISTICS

34. The world leader in industrial and medical gases 34 4. PARAMETERS AFFECTING HYDROGEN EMBRITTLEMENT OF STEELS 4.1. Environment 4.2. Material 4.3. Design and surface conditions

35. The world leader in industrial and medical gases 35  Hydrogen purity  Hydrogen pressure  Temperature  Stresses and strains  Time of exposure 4.1. Environment or “operating conditions”

36. The world leader in industrial and medical gases 36 Influence of oxygen contamination 4.1. Environment or “operating conditions”  Hydrogen purity

37. The world leader in industrial and medical gases 37 Influence of H 2 S contamination  Hydrogen purity 4.1. Environment or “operating conditions”

38. The world leader in industrial and medical gases 38 Influence of H 2 S partial pressure for AISI 321 steel 4.1. Environment or “operating conditions”  Hydrogen pressure

39. The world leader in industrial and medical gases 39 Influence of temperature - Principle  Temperature 4.1. Environment or “operating conditions”

40. The world leader in industrial and medical gases 40 Influence of temperature for some stainless steels 4.1. Environment or “operating conditions”  Temperature

41. The world leader in industrial and medical gases 41  Hydrogen purity  Hydrogen pressure  Temperature  Stresses and strains  Time of exposure 4.1. Environment or “operating conditions”

42. The world leader in industrial and medical gases 42  Microstructure  Chemical composition  Heat treatment and mechanical properties  Welding  Cold working  Inclusion 4.2. Material

43. The world leader in industrial and medical gases 43  Heat treatment and mechanical properties 4.2. Material

44. The world leader in industrial and medical gases 44 4.2. Material  Welding 4.22.01.9 Embrittlement index 25 %8 %2.5 % 0 % (No weld) Ferrite content

45. The world leader in industrial and medical gases 45  Microstructure  Chemical composition  Heat treatment and mechanical properties  Welding  Cold working  Inclusion 4.2. Material

46. The world leader in industrial and medical gases 46  Stress level  Stress concentration  Surface defects 4.3. Design and surface conditions

47. The world leader in industrial and medical gases 47 Crack initiation on a geometrical discontinuity  Stress concentration 4.3. Design and surface conditions

48. The world leader in industrial and medical gases 48 Crack initiation on a geometrical discontinuity  Stress concentration 4.3. Design and surface conditions

49. The world leader in industrial and medical gases 49 FAILURE OF A HYDROGEN TRANSPORT VESSEL IN 1983. HYDROGEN CRACK INITIATED ON INTERNAL CORROSION PITS 4.3. Design and surface conditions  Surface defects

50. The world leader in industrial and medical gases 50 5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 1) All metallic materials present a certain degree of sensitive to HE 2) Materials which can be used  Brass and copper alloys  Aluminium and aluminium alloys  Cu-Be

51. The world leader in industrial and medical gases 51 5. HYDROGEN EMBRITTLEMENT OF OTHER MATERIALS 3) Materials known to be very sensitive to HE : 4) Steels : HE sensitivity depend on exact chemical composition, heat or mechanical treatment, microstructure, impurities and strength  Ni and high Ni alloys  Ti and Ti alloys Non compatible material can be used at limited stress level

52. The world leader in industrial and medical gases 52 6. HYDROGEN ATTACK  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  Heat treatment  Stress level, welding procedure Main parameters summarized on the « Nelson curves » : Other parameters :

53. The world leader in industrial and medical gases 53 6. HYDROGEN ATTACK Nelson curves Legend : Surface decarburization Internal decarburization (Hydrogen attack)

54. The world leader in industrial and medical gases 54 1)The influence of the different parameters shall be addressed. 7. CONCLUSION - RECOMMENDATION

55. The world leader in industrial and medical gases 55 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall cover the following : 7. CONCLUSION - RECOMMENDATION

56. The world leader in industrial and medical gases 56 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall cover the following : The « scope », i.e. the hydrogen pressure, the temperature and the hydrogen purity 7. CONCLUSION - RECOMMENDATION

57. The world leader in industrial and medical gases 57 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall 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 7. CONCLUSION - RECOMMENDATION

58. The world leader in industrial and medical gases 58 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall 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 7. CONCLUSION - RECOMMENDATION

59. The world leader in industrial and medical gases 59 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall 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 7. CONCLUSION - RECOMMENDATION

60. The world leader in industrial and medical gases 60 1)The influence of the different parameters shall be addressed. 2)To safely use materials in presence of hydrogen, an internal specification shall 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 7. CONCLUSION - RECOMMENDATION