0.2 °c/s 0.20 0.15 0.10 o o 0.05 o o • ocP.~ o t. 000, :.. '\~ ... \g~ •• o"f
1·8 C1l c <1l ....J 1.6
11&0' C JO.O"4C, .1.0S'4NI •••.••• oIIISO"C 26.0·~
1400 Temperature .oC 0·03 -1 - -1 ~ QJ en c d .c u 0·02 .c - f!'
196Fig 6.42: The microstructure of wrought alloy SH after agemg the supersaturated 8-ferrite at 900°C for 52 minutes. 197680 I a 580 -,.-... E :i. --Cl) 480 .~ I Cl'
2 v ..., O'l ~ 0.1 o o o o o o
310Table A.5: Equilibrium compositions of <5-ferrite and austenite as calculated using the "Thermocalc" system (wt.
316Table A.ll: Equilibrium compositions of <5-ferrite and austenite as calculated using the "Thermocalc" system (wt.%).
321Table A.16: Equilibrium compositions of <5'-ferriteand austenite as calculated using the "Thermocalc" system (wt.
6.2: Showing a typical form of length and temperature profiles, as monitored on the dilatometer during isothermal transformation of duplex stainless steel. 133lO 10000( ;::!
6.2.8 Metallography of I~othermally Transformed Weld Alloy Wlll Transformation at 1000°C At this temperature, the allotriomorphic austenite layers formed on the 8 grain boundaries were observed to be thicker than those obtained with the wrought alloy SH.
6.26 a: Optical micrographs showing the microstructure of samples of welded alloy vVll1 after isothermal transformation at 800°C for 300 seconds.
6.26 b: Optical micrographs showing the microstructure of samples of welded alloy VV111after isothermal transformation at 900°C for 300 seconds. (To = 1300°C, ferritisation time = I sec).
6.28: Optical micrograph showing the decarburized region (free of austenite), observed at the outer surface of a sample of welded alloy "VIII after isothermal treatment at 1000°C for 300 seconds.
(1979). 6.62: Microstructure of a sample of alloy R4P, after direct isothermal transformation from the 8+/ phase field at 900°C for 15 minutes.
a: Influence of nitrogen on 8-ferrite content and primary grain size of TIG weld metal (bases composition ~ 24.4 Cr, 7 Ni wt.%), . 0.1 02 0.3 0.4 (Qr~On (on(en~ration Wt~ V. in cm/rnin t1)/' in. V. in c.m/min t'11'
A.12: Equili bri urn cornposi tions of 0'- ferri te and austeni te as calculated using the "Thermocalc" system (wt.
A.2: The calculated partition coefficient "K", defined as C"JCa where C-y is the concentration (wt.%) of the element in austenite and Co is the concentration (wt.%) of the element in b-ferrite, as varied with temperature.
(1973). Achema-Congress Frankfurt-am-Main,
(1987). Advances in "Velding Science
Alloy Tageing tT . Volume Fraction Micro- Hardness ageing (QC) (hI's) 'Y 8 a 'Y 8 a
I ~,f •• !' I...., 'IA"_./' j .' 1-. ',"" I ~.---'-', !", 1/\\\ '~l. ~~" , • ,:'t ••. .' "'~ "'~1 \ \ ." .. ",;,'" "" \ V ~ I ' •• ' "","'," j,;F r I~ I \.
i\Trought alloy R2PP Temperature K Element Phase
(1982). Iron-Binary Phase Diagrams'
Isothermal transformation diagrams showing the austenite volume fraction as a function of time for alloy SHP. Fully ferritic samples were upquenched to the isothermal temperatures. (a) linear time scale; (b) log time scale.
(2000). Material \Velding Consumable Postweld Samples thickness, process type heat Environment* failed** (mm) treatment 10
(1959). Metallurgie de la Soudure,
(1973). Metals Handbook
Microstructure of samples of wrought duplex stainless steel IC373, after ageing for 48 hours at: (a) 1120°C (b) 980°C (c) 790°C (d) 650°C In a & d, the white phase is austenite and the dark phase is the D-ferrite.
Microstructure of samples of wrought duplex stainless steel IC378, after ageing for 48 hours at: (a) 1120°C (b) 980°C (c) 790°C (d) 650°C In a & d, the white phase is austenite and the dark phase is the b-ferrite.
(1988). Offshore Mechanics and Arctic Engineering (O~AE)',
(1988). Ph.D. Thesis,
phase Fe Cl'
(1978). Physical Metallurgy of Weldments',
(1974). Physical Metallurgy Principles'
(1983). Publ. by American Society for Metals,
(1982). Publ. by ASM
(1968). rehealed dolo painls ."',( If ~ .-:..: '-..... .. -;-------'---o 1-0 /5 10 25 30 Fig. 3.24: The relationships between the compositional factors P, P mod. and P* and the measured austenite content of the weld metal . 81References 1. \Vittke,
(1982). Solidification and Casting of Metals London, The Metals Society,
(1983). Stahl u.
(1967). Stainless and Heat Resisting Steels',
(1973). Stress Corrosion Cracking and Hydrogen Embrittlement of Iron Base Alloys,
t Solution treated at 1250 0e for"72 hours. 277Fig. 8.1: A set of colour micrographs showing the microstructure of samples of coarse grained SH alloy after continuous cooling treatment at different cooling rates(Q): (a) Q =
Table 5.1: Effect of dilution on composition of BW' (atomic%). The atomic percent value stated ignores the presence of any interstitials. (Accuracy ±2%) Region Fe er Ni Mo Mn Si martensite
Table 6.3: Calculated lattice parameter of austenite according to equation (6.6) Material C (atomic%) N (atomic%) a~ (nm) a~* (nm)
Table 8.2: Experimental data and results of grain size and austenite volume fraction measurements for continuously cooled SH and \V111 alloys:
Table A.3: The calculated partition coefficient "K", defined as C... JCa where C-y is the concentration (wt.%) of the element in austenite and Ca is the concentration (wt.%) of the element in b-ferrite, as varied with temperature.
(1987). Table A.l: The calculated partition coefficient "K", defined as C)Co where C-r is the concentration (wt.%) of the element in austenite and Co is the concentration (wt.%) of the element in 8-ferrite, as varied with temperature.
Tageing°C Phase Fe Cr Ni Mo Mn Si 800 0"
(1969). Tarmebehandlung von Stahl. Metallkundliche Grundlagen
(1972). Telding Handbook, Vol. 4 'Metals and Their 'Veldability
(1985). The \Veld.
(1958). The effect of thermal grooving as characterised by Mullins
(1985). The Inst. of Metals,
The microstructure of the as-quenched specimens is shown in (Fig. 6.59). Even after solution treatment at 1350°C for 15 minutes, small amounts of austenite persisted, but 216in general ~ 99 % of the microstructure was found to be ferritic.
(1985). The vVeld.
(1985). The Weld.
Ti Al Cu
Time at Tiso (min)
Time, seconds b Fig. 6.8: Showing isothermal transformation diagrams of the volume fraction of austenite as calculated from the measured length change, obtained from dilatometric experiments, versus 8 ---+ I reaction time, for samples of welded alloy B\V.
Time, seconds Fig. 6.24: Showing isothermal transformation diagrams of the volume fraction of austenite as calculated from the observed length changes, versus 8 ----t I reaction time, for alloy "VVll1. (T cS = 1290°C, ferritisation time
Tiso tT- V-y V-y ,"0 pm (QC) (QC) (mins)
Tlme (,) I1 Tlme (,) , I" 18el Fig. 6.30: Analysis of isothermal transformation diagrams of welded alloy BW in terms of a Johnson-11ehl A\Tami type equation. 1771000·C 1.9£ .•. 99 ." '.~ I.BE .•.ee ..
(1978). Trends in Steels andConsumablesfor Welding',
(1988). Velding Metallurgy of Stainless Steels'
(1988). vVelding Metallurgy of Stainless Steels'
Welded alloy WR2 Temperature K K= c"/
(1988). Welding Metallurgy of Stainless Steels'
Wrought alloy SH Ferritisation ~ I, t I " ~;,/ ,'~" .- ~... 0.029 ..•..... ~ :s 0.028 Cl) bD 0.027 ~ Cd ..c: u ..c: 0.026 -+-'
Z ::r:: ;>-280 tIl tIl QJ ~ "0 """ 260 c= ::r::