carbon equivalent
TRANSCRIPT
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Basicity Index Type Equations Basicity Index Type Equations -- II
2
%' ,1869%
O from Metal OxideMrajek s Index MrazekO from SiO
= −
2
% ,1901%
CaOVee Ratio BlumSiO
= −
BCaO MgOSiO P O
=++
% .% .
14%0 84%2 2 5 B I
Sum of Basic OxidesSum of Acidic Oxides
. .=
( ) ( )B CaO MgO MnO SiO P O TiO= + + − + +% % % % % %2 2 5 2
BCaO
SiO Al OLF =+
%% %2 2 3
BCaO MgOSiO Al OLF =
++
% .% .
14%0 6%2 2 3
( )( )B
CaF CaO MgO BaO SrO Na O K O Li O MnO FeOSiO Al O TiO ZrO
=+ + + + + + + + +
+ + +2 2 2 2
12
21
2 2 3 2 2
( )( )B
CaO MgO BaO SrO Na O K O Li O MnO FeOSiO Al O TiO ZrO
=+ + + + + + + +
+ + +2 2 2
12
21
2 2 3 2 2 Tuliani’s Formula, 1978Tuliani’s Formula, 1978
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Basicity Index Type Equations Basicity Index Type Equations -- IIII
Optical BasicityElectron Donor Power of Oxygen in Oxide Systems
Electron Donor Power of Free Oxide Anions=
O BZ R
GZ Coordination Numberof Cation A
RMolesof Cation A
Molesof Oxygen AtomsG Basicity Moderating Parameterdependingon Pauling sElectronegativity
A A
AAllCations
A
A
A
. .
##
'
=
=
=
=
∑ 21971 - Duffy and Ingram1971 - Duffy and Ingram
BIonicFractionof Free AnionsO intheDissociated Slag
Sumof All AnionsandCationsof theSystemZ =−2
( )( ) ( )B
m m m m m
m m m m m m m nZ
Me O MeO Al O SiO TiO
Me O MeO CaF BaF SiO TiO Al O O
=+ − + +
+ + + + + + +
∑ ∑∑ ∑ −
2 2 3 2 2
2 2 2 2 2 2 3 2
2 2
2 3 2Zeke, 1980Zeke, 1980
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
High and Medium Strength Steels High and Medium Strength Steels Subjected to Welding Heat CycleSubjected to Welding Heat Cycle
Comparison between High and Low Heat Inputs Comparison between High and Low Heat Inputs
(Svensson, 95)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Heat Heat Affected Affected Zone Zone Properties Properties
((DürenDüren, Korkhaus, and Niederhoff, 3R International, 87), Korkhaus, and Niederhoff, 3R International, 87)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Typical Problems observed in High Typical Problems observed in High Strength Steel WeldingStrength Steel Welding
Metallurgical Origin:HAZ CrackingWM MicrofissuringHAC Cracking
(Rowe and Liu, 99)
(Rowe and Liu, 99)(Rowe and Liu, 99)
Processing Origin:Processing Origin:Porosity at Long Arc or Improper StartPorosity at Long Arc or Improper StartSlag Inclusions at Low CurrentSlag Inclusions at Low CurrentVariable Current at Different PositionsVariable Current at Different Positions
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Map: Cracking Steel Weldability Map: Cracking ConcernsConcerns
(Graville, 76)
(ASM, Welding Handbook V. 6, 93)
HSLA-80/100
HY-80/100
HSLA-65
EH-36
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Indices Steel Weldability Indices -- Carbon Carbon Equivalent Type ExpressionsEquivalent Type Expressions
IIWIIW
WintertonWinterton
CottrellCottrell
*
6 5 15+ + + +
= + + +Mn Si Cr Mo V Ni CuCE C
6 40 10 20 50 10= + + + + − −
Mn Cu Cr Ni Mo VCE C
0.00016 5 3 4
+= + + + + +
Mn Cr Mo V NbCE CC S
* Omitted in the original Dearden & O’Neill formula
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
DnVDnV
DD
PPCMCM
CENCEN
Steel Weldability Indices Steel Weldability Indices -- Carbon Carbon Equivalent Type ExpressionsEquivalent Type Expressions
24 10 40 5 4 14+
= + + + + + +Si Mn Ni Cu Cr Mo VCE C
25 16 20 20 15+ +
= + + + + +Si Mn Cu Cr Ni Mo VCE C
530 20 15 10 60
+ += + + + + + +CM
Si Mn Cu Cr Mo V NiP C B
( ) 524 6 15 20 5
+ + +⎡ ⎤= + ⋅ + + + + +⎢ ⎥⎣ ⎦Si Mn Cu Ni Cr Mo Nb VCEN C A C B
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Indices Steel Weldability Indices –– Fundamental Fundamental ApproachesApproaches
Thermodynamic ApproachThermodynamic Approach'
' 'Mn Si C
oMn Si
C K Mn K Si K CLnCCE K
K MnLnMn K SiLnSi
⎡ ⎤+ + + += ⎢ ⎥
+ + +⎢ ⎥⎣ ⎦
…
…
Kinetics Approach
[ ]1o C Mn SiCE K C K C K Mn K Si′ ′ ′ ′= + + + +…
Partitioning Approach
1 C Mn Si LCo
LC LMn LSi
K C K Mn K Si K LnCCE K C
K CLnC K MnLnMn K SiLnSi′′ ′′ ′′ ′′+ + + + +⎡ ⎤
′′= ⎢ ⎥′′ ′′ ′′+ + + +⎣ ⎦
……
(Liu et al., 1986)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Indices Steel Weldability Indices -- Carbon Carbon Equivalent Type ExpressionsEquivalent Type Expressions
YuriokaYurioka
( ) ( )
( )
80
8 / 5
442 99 206 402 90 arctanlog 2.3 1.35 0.882
1.15 0.673 0.601
24 6 15 12 8 4
24 5 10 18 2.5 3
3.6 20 9
+= + + + − ⋅
− − +=
− −
= + + + + + + + ∆
+ += + + + + + +
= + + + +
Max II II
I III
I III
I
II
III
H C CE C CE xt CE CEx rad
CE CESi Mn Cu Ni Cr MoCE C H
Si Mn Cr V Cu Ni Mo NbCE C
Mn Cu NiCE C5 4
+Cr Mo
( ),∆ =H f B N ( )2884 1 0.3 294= − +MHV C CFor fully martensite microstructure:
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Indices Steel Weldability Indices --∆∆tt8/58/5 CalculationCalculation
Rosenthal Solution (1946)
∆t8/5 is directly related to the heat input (H)
48 5 8.149 10
2Ht x ηπκ
− ⎛ ⎞∆ = ⎜ ⎟⎝ ⎠
26
8 5 22.767 104 p
Ht xh C
ηπκρ
−⎛ ⎞
∆ = ⎜ ⎟⎜ ⎟⎝ ⎠
η = Efficiency
H = Heat input
κ = Thermal conductivity
ρ = Specific gravity
Cp = Specific Heat
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Steel Weldability Indices Steel Weldability Indices -- Carbon Carbon Equivalent Type ExpressionsEquivalent Type Expressions
Lorenz & DürenLorenz & Düren
DürenDüren –– For 100% Microstructure (M or B) in HAZ
( ) ( ) ( )8/ 5 8 / 5
*
2019 1 0.5log 0.3 66 1 0.8log
8 11 5 6 3 17 9
16 25 10 15 40
= − ⋅ + − + −⎡ ⎤⎣ ⎦
= + + + + + + +
+ += + + + + +
H t C CE C t
Mn Si Cr Mo V Ni CuCE C
Mn Cu Si Cr V Mo NiCE C * For pipeline grade steels
For 100% Microstructure (M or B) in HAZ802 305
350 1018 11 5 6 3 17 9
= +
⎛ ⎞= + + + + + + + +⎜ ⎟⎝ ⎠
M
B
HV CMn Si Cr Mo V Ni CuHV C
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
WELD STRENGTH MODEL WELD STRENGTH MODEL
( ) ( )( )
0.2
0.178 / 5
3.1 0.1 80
0.065
= −
=
nP MaxR MPa H
n tAkelsen, Rørvik, Onsøien, and Grong
50232 1.9 0.26 0.09= + − −YS t T GS
50313 8.3ln 1.8 3.8 0.36 0.08⎛ ⎞= − + − −⎜ ⎟⎝ ⎠
dTUTS t T GSdt
Blackburn et al. (1997)
YS = 0.2 % offset yield strength, ksit = thickness, cmT50 = 50 % transformation temperature, oCGS = austenite grain sizeUTS = ultimate tensile strength, ksi
= calculated cooling rate, oC/sdTdt
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Application: Steel Weldability IndexApplication: Steel Weldability Index
WeldMetal
BaseMetal
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Heat Affected Heat Affected Zone PropertiesZone Properties
Empirical Relationships
(Svensson, 95)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Weld Metal Weld Metal Properties
(Svensson, 95)
Properties
Empirical Empirical RelationshipsRelationships
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.500
50
100
150
200
250
Risk of Cracking
No Cracking
TM Steels up to X-100
Pre
heat
ing
Tem
pera
ture
(o C)
Carbon Equivalent (%)
Possibilities of CrackPossibilities of Crack--Free Free XX--100 Steel Welds 100 Steel Welds
6 mm Cylindrical Specimens 6 mm Cylindrical Specimens with spiral notchwith spiral notchHeat Input: 8Heat Input: 8--9 kJ/cm9 kJ/cmThickness of Backing Plate: Thickness of Backing Plate: 20 mm20 mmCritical implant Critical implant Stress/Yield Strength: Stress/Yield Strength: 100%100%[H][H]DifDif ≥ ≥ 40 cm40 cm33/100g/100g
(According to Implant Test Resultsusing Cellulosic Electrodes)
(Hillenbrand, Niederhoff, Hauck,Pertender, Wellnitz, 1997)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Hydrogen Embrittlement Susceptibility:Hydrogen Embrittlement Susceptibility:Martensite Start Temperature Martensite Start Temperature -- MsMs
∆ ∆ Martensite Start Temperature Martensite Start Temperature -- ∆∆MsMsAndrew – Linear (1965)Ms = 539 – 423C – 30.4Mn – 17.7 Ni – 12.1Cr – 7.5Mo
Self et al. (1986) – Wrought Metal:Ms = 521 – 350C – 14.3Cr – 17.5Ni –28.9Mn – 37.6Si – 29.5Mo
– 1.19Cr.Ni + 23.1(Cr+Mo)CSelf et al. (1986) – Weld Metal:Ms = 521 – 350C – 13.6 Cr – 16.6Ni – 25.1Mn – 30.1Si – 40.4Mo
– 40 Al – 1.07Cr.Ni + 21.9(Cr+0.73Mo)C
∆Ms = MsWM - MsHAZ
Other Ms Equations include Payson & Savage (1944), Carapella (1944), Rowland & Lyle (1946), Grange & Stewart (1946), Nehrenberg (1946), Steven & Haynes (1956), and Others.
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
CrackingCracking--No Cracking MapNo Cracking Mapfor High Strength Steel Weldsfor High Strength Steel Welds
(Wang and Liu, 97)
(Rowe and Liu, 99)
(Olson, Wang, Liu et al, 96)
Colorado School of Mines Colorado School of Mines -- CSMCSMCenter for Welding, Joining and Coatings Research Center for Welding, Joining and Coatings Research -- CWJCRCWJCR
Weld Undermatching and Overmatching:Weld Undermatching and Overmatching:NonNon--Uniform Hydrogen DistributionUniform Hydrogen Distribution
MicrofissuringTransverse Cracking
-60 -40 -20 0 20 40 60-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
∆H (H
WM -
HH
AZ) (
ml/1
00g
met
al.a
tm1/
2 )
∆Ms (MsWM - MsHAZ) (oC)
OvermatchedWeld Metal
OvermatchedWeld Metal
EvenmatchedWeld Metal
EvenmatchedWeld Metal
UndermatchedWeld Metal
UndermatchedWeld Metal
HAZCracking
(Wang and Liu, 97)