Chapter 10. Phase Diagrams - SKKUhome.skku.edu/~femlab/lecture/introduction_mse/lecture10.pdf ·...
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Chapter 10. Phase Diagrams
Transcript of Chapter 10. Phase Diagrams - SKKUhome.skku.edu/~femlab/lecture/introduction_mse/lecture10.pdf ·...
Chapter 10. Phase Diagrams
Fe-Fe3C 상태도
Fe C SystemFe-C System
※ 상 (phase)
- ferrite (α-Fe, δ-Fe) : bcc
- austenite (γ-Fe) : fcc
- cementite (Fe3C) : orthorhombic 구조의 금속간화합물, 준안정상
※ 조직 (microstructure)
- ledeburite : 공정조직ledeburite 공정조직
- pearlite : 공석조직
- martensite : γ-range 에서 급냉에 의한 격자변태로 생기는 조직
- bainite : γ-range 에서 450~250℃ 근처까지 급냉 후 등온변태로 생기는 조직
- widmannstatten : proeutectoid ferrite와 proeutectoid cementite가 교차
[111] [100] 방향으로 뻗어나간 조직[111], [100] 방향으로 뻗어나간 조직
※ Fe-cementite (Fe3C, 6.67wt.%C)상태도
Eutectic
ledeburite강 주철E t t id 강 주철Eutectoid
pearlite
α-ferrite γ-austenite
eutectoid reactioneutectoid reaction
P liPearlite
Fe Fe C pearliteFe-Fe3C pearlite
H id AllHypoeutectoid Alloys
pearlitet t id pearliteproeutectoid α
pearlite
proeutectoid α
L R lLever Rule
• Pearlite의 양 (W )?Pearlite의 양 (Wp)?
UTTWp +
=UT +
74.0022.0
022.076.0022.0 '
0'0 −
=−−
=CC
• proeutectoid α의 양 (Wα)?
UTUW+
='α
74.076.0
022.076.076.0 '
0'0 CC −
=−−
=
Hypereutectoid AlloysHypereutectoid Alloys
proeutectoid Fe3Cpearlite
L R lLever Rule
Pearlite의 양 (W )?• Pearlite의 양 (Wp)?
XVXWp = XVp +
94570.6
76070670.6 '
1'1 CC −=
−−
=94.576.070.6 −
• proeutectoid Fe3C의 양 (Wcem)?p 3 ( cem)
XVVWcem +
=XV +
94.576.0
76.070.676.0 '
1'1 −
=−−
=CC
94.576.070.6
HW# 3 (~ 4/10)HW# 3 (~ 4/10)
Chapter 5 # 5 7 # 5 25 # 5 31Chapter 5. # 5.7 # 5.25 # 5.31
Chapter 6. # 6.12 # 6.21 # 6.D4p
Chapter 10. #10.37 #10.43 #10.47 #10.53
