- Calculation of some transformation
temperatures (K .W.
Andrews….)
Ac3 (°C) = 910-203Ö(C)-15.2Ni+44.7Si+104V+31.5Mo+13.1W-(30Mn+11Cr+20Cu-700P-400Al-120As-400Ti)
Ac1 (°C) =
723-10.7Mn-16.9Ni+29.1Si+16.9Cr+290As+6.38W
Ms (°C) =
539-423C-30.4Mn-17.7Ni-12.1Cr-7.5Mo
- Transformation
of austenite to ferrite after hot rolling (Chiaki
Ouchi et al, Tetsu to Hagane, 67 (1), Jan. 1981)
Ar3
(°C) = 910-310C-80Mn-20Cu-15Cr-55Ni-80Mo+3.5(t-8)
t = plate thickness (mm)
Ar3
dependence on cooling rate V (°C/s) (unpublished
data)
Ar3
(°C) = 820.exp(-0.0602.logV) for
C=0.029, Mn=0,57, Nb=0,09
Ar3
(°C) = 731.exp(-0.0487.logV) for
C=0.11, Mn=1.06, Cu=0.16, Mo=0.15, V=0.034, 16ppm B
Ar3
(°C) = 535.exp(-0.0711.logV) for.
C=0.11, Mn=0.88, Cu=0.34, Cr=0.90, Mo=0.37
- Austenite
recrystallization stop temperature (Ronaldo
A. N. M. et al, ….)
Tnr (°C) =
897+464C+[6445Nb-644Ö(Nb)]+[732V-230Ö(V)]+890Ti+363Al-357Si
- Bainite
start temperature
Bs (°C) =
719-127C-50Mn-31Ni-27Cr-61Mo (Bodner
R. L. and Taylor K. A. Iron & Steel making 18 (8), Aug. 1990)
Bs (°C) =
830-270C-90Mn-37Ni-70Cr-83Mo (Steven
and Hayes..)
- Susceptibility
to Stress relief cracking in weld joints
J
embrittlement Factor= (%Si+%Mn)*(%P+%Sn)*10-4 = 200 (maximum)
Bruscato
Parameter= (10P+4Sn+15Sb+As)/100 < 23
(elements in ppm)
- Hardenability
Parameter in controlled rolled acicular ferrite steels
HP =
32,5Mo+10(Mn+Cr)+2,5Ni > 23, when yield point elongation tends to zero (C. M. Brown and D. B. McCutheon. Steels
for linepipe and pipeline fittings…)
- Carbon
Equivalent Value (General
reference: Hruyoshi Suzuki, Weldability of modern structural steels)
CE
(International Institute of Welding) = C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15
CEN
(Yurioka) = C+A*(Si/24+Mn/6+Cu/15+Ni/20+(Cr+Mo+Nb+V)/5+5B
A = 0,75+0,25*tanh [20(C-0,12)] A depends on carbon content as follows
|
%C |
<0.06 |
0.06 |
0.07 |
0.08 |
0.09 |
0.10 |
0.11 |
0.12 |
0.13 |
0.14 |
0.15 |
|
A |
0.53 |
0.54 |
0.56 |
0.58 |
0.62 |
0.66 |
0.70 |
0.75 |
0.80 |
0.85 |
0.80 |
Pcm =
Cracking carbon equivalent =C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/15+V/10+5B
CE
(Graville) = C+Mn/16-Ni/50+Cr/23+Mo/7+Nb/8+V/9
-
Globularization of non metallic inclusions (oxides and sulphides) in calcium
treated steels
ACR (Atomic
Concentration Ratio) = 0,80*(Ca/S)*(1-98*O > 1,8
and Ca/S
> 2,0