Your SlideShare is downloading. ×
0
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Posco Bainite 1
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Posco Bainite 1

1,587

Published on

Slide shows on bainite lectures by Prof. H. K. D. H. Bhadeshia

Slide shows on bainite lectures by Prof. H. K. D. H. Bhadeshia

Published in: Education, Technology, Business
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,587
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
114
Comments
0
Likes
3
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. POSCO Lectures on Bainite Graduate Institute of Ferrous Technology <ul><li>Microstructure </li></ul><ul><li>Mechanism </li></ul><ul><li>Properties </li></ul><ul><li>Superbainite </li></ul>
  • 2. http://cml.postech.ac.kr/
  • 3. To understand bainite, we must consider all other microstructures in steels
  • 4. Bundy (1965)
  • 5. Allotropes of iron in three dimensions
  • 6. Cementite Fe 3 C
  • 7. Steel: Fe-C ferrite austenite
  • 8. Fe 3 C
  • 9. Diffusionless Diffusion
  • 10.  
  • 11.  
  • 12. Allotriomorpic Idiomorphic ferrite
  • 13.  
  • 14.  
  • 15.  
  • 16.  
  • 17.  
  • 18. Pearlite
  • 19. 20 µm
  • 20.  
  • 21.  
  • 22. Jaramillo et al., 2004
  • 23.  
  • 24.  
  • 25.  
  • 26. Martensite
  • 27. Ferrite Austenite
  • 28.  
  • 29.  
  • 30. transformation twins (Wayman)
  • 31. 50 m m
  • 32.  
  • 33. austenite
  • 34. Chang and Bhadeshia
  • 35.  
  • 36. Bainite
  • 37.  
  • 38. 1 µm upper bainite
  • 39. lower bainite
  • 40. Surface 1 Surface 2 Srinivasan & Wayman, 1968 50 µm
  • 41.  
  • 42.  
  • 43.  
  • 44.  
  • 45. 50 µm
  • 46. Bhadeshia and Waugh, 1981
  • 47. Takahashi and Bhadeshia
  • 48. Temperature / °C Decarburisation time / s Fe-0.4C wt% 500 400 300 0 1 2
  • 49.  
  • 50.  
  • 51. Bhadeshia & Edmonds, 1979
  • 52.  
  • 53.  
  • 54. TRIP-assisted steel Fe-0.29C-1.41Si-1.42Mn wt% (Jacques, 2001)
  • 55.  
  • 56. Growth is diffusionless. Strain energy must be accounted for.
  • 57. Takahashi and Bhadeshia
  • 58.  
  • 59. Oka and Okamoto
  • 60. Ohmori and Honeycombe
  • 61. The mechanism of transformation is displacive. Transformation temperature higher than martensite. Bainite grows without diffusion. But carbon then escapes into the residual austenite. Shape deformation plastically accommodated. Sub-unit mechanism of growth Summary
  • 62. Think of bainite as martensite which tempers during transformation
  • 63.  
  • 64.  
  • 65. DISPLACIVE RECONSTRUCTIVE
  • 66.  
  • 67.  
  • 68.  
  • 69.  
  • 70.  
  • 71.  
  • 72. Watson and McDougall, 1973
  • 73.  
  • 74.  
  • 75.  
  • 76. Mechanism displacive but carbon must partition during growth. Pairs of plates grow together to minimise strain. Summary
  • 77. Nucleation of martensite, bainite, Widmanstätten ferrite
  • 78.   x Gibbs free energy Carbon Thermodynamics  G m x  m   G
  • 79.  
  • 80. T h G N
  • 81. Bhadeshia, 1981 Each point represents a different steel Nucleation function G N
  • 82. The nucleation of bainite must involve the partitioning of carbon Why does the required free energy vary linearly with T?
  • 83. hexagonal close-packed cubic close-packed Christian, 1951
  • 84. Brooks, Loretto and Smallman, 1979
  • 85. Olson & Cohen, 1976
  • 86.  
  • 87.  
  • 88.  
  • 89. Nucleation of bainite must involve the partitioning of carbon. Mechanism of nucleation is otherwise identical to that of martensite.
  • 90.  
  • 91.  
  • 92.  
  • 93.  

×