Welding Metallurgy. Sindo Kou

11.5 Dilution of filler metal by base metal.Figure 11.6 Dilution levels determined by geometric calculations in good agr...Figure 11.7 Good agreement between Ni and Cr contents determined by geometri...Figure 11.8 Dissimilar filler metal changing composition of bulk weld metal ...Figure 11.9 Macrosegregation Mechanism I, T _LW < T _LB, for dissimilar...Figure 11.10 Verification of Mechanism I in welding 1100 Al (~ pure Al) with...Figure 11.11 Macrosegregation Mechanism II, T _LW > T _LB, for dissimil...Figure 11.12 Verification of Mechanism II in welding heat‐treated Al‐33Cu eu...Figure 11.13 Verification of Mechanism II in welding pure Cu with filler met...Figure 11.14 Pure Ni bead‐on‐plate welded with pure Cu filler wire: (a) tran...Figure 11.15 Pure Cu bead‐on‐plate welded with pure Ni filler wire: (a) tran...Figure 11.16 A36 steel welded with filler metal 309L stainless steel: (a) tr...Figure 11.17 Formation of layers of islands by Mechanism I under weld pool f...Figure 11.18 Schaeffler's diagram showing compositions of weld and beach in ...Figure 11.19 309 stainless steel welded with filler metal ER70 steel: (a) tr...Figure 11.20 Schaeffler's diagram showing compositions of weld and beach in ...Figure 11.21 Mechanism I for macrosegregation in dissimilar‐metal welding un...Figure 11.22 Mechanism II for macrosegregation in dissimilar‐metal welding u...Figure 11.23 Transverse macrograph of Cu‐to‐steel arc weld: (a) overall stru...Figure 11.24 Composition measurements by EPMA inside and across the weld....Figure 11.25 Microstructure in Cu‐to‐steel weld: (a) layered fusion zone; (b...Figure 11.26 Metastable miscibility gap below equilibrium liquidus line show...Figure 11.27 Slow diffusion during cooling can cause deviation from gap, Fe‐...Figure 11.28 Summary of segregation features in dissimilar‐metal welding rev...Figure 11.29 Elimination of unmixed zone (base‐metal beach) by ultrasonic vi...Figure 11.30 Filler metal dilution and composition in dissimilar‐metal weldi...Figure 11.31 Macrosegregation in a multiple‐pass weld between 4130 steel and...Figure 11.32 Variations in microstructure in a multiple‐pass weld between 41...Figure E11.2 1100 Al welded with filler metal 4145 Al: (a) transverse microg...Figure P11.1 1100 Al welded with Al‐52.5Cu filler wire: (a) transverse micro...Figure P11.2 Transverse macrograph of Cu‐30Ni alloy welded with pure Ni as f...

      12 Chapter 12Figure 12.1 Wood's metal quenching: (a) top view of weld pool and surroundin...Figure 12.2 Microstructure near centerlines of top surfaces of 304 stainless...Figure 12.3 Microstructure in the fusion zone far behind the bottom of the m...Figure 12.4 Formation of vermicular and lathy ferrite: (a) mechanism; (b) la...Figure 12.5 Schaeffler diagram for predicting weld ferrite content and solid...Figure 12.6 Effect of nitrogen on ferrite content in gas–tungsten arc welds ...Figure 12.7 WRC‐1992 diagram. Transformation sequence for each mode shown....Figure 12.8 WRC‐1992 diagram with martensite boundaries for 1, 4, and 10% Mn...Figure 12.9 Experimentally measured ferrite number (FN) versus predicted FN:...Figure 12.10 Vertical section of Fe–Ni–Cr phase diagram at 59% Fe showing se...Figure 12.11 Electron beam travel speed (cooling rate) versus composition ma...Figure 12.12 Vertical section of Fe–Cr–Ni phase diagram showing change in so...Figure 12.13 Continuous cooling transformation diagram for weld metal of low...Figure 12.14 Micrographs showing typical weld metal microstructures in low‐c...Figure 12.15 Acicular ferrite and inclusion particles in a low‐carbon, low‐a...Figure 12.16 Schematic sketch showing effect of alloy additions, cooling tim...Figure 12.17 Continuous cooling transformation diagram for weld metal of low...Figure 12.18 Prior austenite grain diameter as a function of weld metal oxyg...Figure 12.19 Acicular ferrite content as a function of shielding gas oxygen ...Figure 12.20 Subsize Charpy V‐notch toughness values as a function of volume...Figure 12.21 Weld metal Charpy V‐notch toughness expressed as transition tem...Figure 12.22 SEM images of weld metal of an ultralow carbon bainitic steel: ...Figure 12.23 SEM image of interlaced multiphase microstructure of a steel we...Figure 12.24 Results of creep‐rupture tests replotted in terms of Larson‐Mil...Figure 12.25 δ‐ferrite in fusion zone of high‐Al weld in as‐welded condition...Figure 12.26 Quasi‐binary phase diagram of P91 steel calculated using Thermo...Figure 12.27 SEM images of the weld metals: (a) high Al‐weld showing coarse ...Figure 12.28 Precipitation of nitrides: (a) AlN dominating in high‐Al weld; ...Figure 12.29 Idealized liquidus projection of ternary Fe‐Cr‐C phase diagram....Figure 12.30 Transverse cross‐section of an overlay showing its dilution by ...Figure 12.31 Effect of AC balance (fraction of time in electrode positive) o...Figure 12.32 Microstructure variation across thickness of Cr‐carbide overlay...Figure 12.33 Typical microstructure of Ni‐WC overlay deposited by GMAW.Figure 12.34 Poly Tung NiBWC tubular wire: (a) transverse cross‐section; (b)...Figure 12.35 Four‐layer square overlay made by GMAW‐CSC: (a) motion patterns...Figure 12.36 Microstructure and composition of Ni‐WC overlay: (a) SEM image ...Figure 12.37 Thermodynamic analysis of Ni‐39.58W‐1.08C‐0.67B‐0.36Fe‐0.34Si: ...Figure 12.38 Thermodynamic analysis of Ni‐39.58W‐1.08C‐0.67B‐0.36Fe‐0.34Si‐5...Figure E12.2 Microstructure of 309 stainless steel revealed by quenching wit...

      13 Chapter 13Figure 13.1 Solidification cracking in bead‐on‐plate weld of 6061 Al (~Al‐1M...Figure 13.2 Solidification cracking in an autogenous bead on plate weld of 7...Figure 13.3 Solidification cracking in 2024 Al (~Al‐4.4Cu‐1.5Mg) lap weld ma...Figure 13.4 SEM images of fracture surfaces of 5083 Al (Al‐4.5Mg) welds: (a)...Figure 13.5 Columnar grains and solidification cracking: (a) columnar grains...Figure 13.6 Solidification cracking criterion and crack susceptibility index...Figure 13.7 Solidification of succinonitrile‐acetone organic alloy (from lef...Figure 13.8 Calculated crack susceptibility of wrought Al alloys consistent ...Figure 13.9 Predictions of crack susceptibility reduction by filler metals: ...Figure 13.10 Spikes occasionally found on fracture surfaces after cracking d...Figure 13.11 Mechanism of spike formation without solid‐to‐solid bridging be...Figure 13.12 Binary Al‐Cu system: (a) phase diagram; (b) maximum steepness a...Figure 13.13 Binary Al‐Cu system: (a) phase diagram; (b) T‐(f _S)^1/2 cur...Figure 13.14 Calculating peak crack susceptibility of binary alloy system: (...Figure 13.15 Varestraint test (most widely used crack susceptibility test si...Figure 13.16 Varestraint test results: (a) ferritic stainless‐steel weld aft...Figure 13.17 Controlled tensile weldability (CTW) test: (a) front view; (b) ...Figure 13.18 Transverse‐motion weldability (TMW) test: (a) schematic; (b) ph...Figure 13.19 Normalized crack length: (a) overview; (b) weld enlarged. Trave...Figure 13.20 TMW test results of Al alloys: (a) 2219 Al; (b) 2024 Al; (c) 70...Figure 13.21 Susceptibility of commercial wrought Al alloys to solidificatio...Figure 13.22 Effect of filler metals on crack susceptibility of 6061 Al show...Figure 13.23 Crack susceptibility reduction of 2024 Al by filler metals: (a)...Figure 13.24 Comparison between Varestaint test and transverse‐motion weldab...Figure 13.25 Circular‐patch welding test: (a) top view of specimen; (b) vert...Figure 13.26 Solidification cracking in circular‐patch welding of 3.2 mm thi...Figure 13.27 Houldcroft test specimen.Figure 13.28 Cast pin test.Figure 13.29 Constraint‐rod casting: (a) mold design; (b) cracks in a Mg cas...Figure 13.30 Ring casting for testing susceptibility to cracking during soli...Figure 13.31 Vertical sections of Fe‐Cr‐Ni ternary phase diagram: (a) 304 (~...Figure 13.32 Room‐temperature microstructure in fusion zones of stainless st...Figure 13.33 Results of circular‐welding tests of solidification cracking su...Figure 13.34 Solidification crack susceptibility of austenitic stainless ste...Figure 13.35 Microstructure near centerline of top surface of 304L weld quen...Figure 13.36 Microstructure near centerline of top surface of 310 weld quenc...Figure 13.37 Explaining why fine equiaxed grains are less susceptible to sol...Figure 13.38 Effect of grain size on solidification cracking of 7108 Al (~Al...Figure 13.39 Nb‐bearing superalloys: (a) microstructure of one alloy contain...Figure 13.40 Effect of solidification paths (solid lines) on solidification ...Figure 13.41 Effect of solidification paths (thick lines) on solidification ...Figure 13.42 Effect of alloying elements on the solidification temperature r...Figure 13.43 Binary Al‐Mg system (Compare with Al‐Cu in Figure 13.13): (a) p...Figure 13.44 Effect of Cu back diffusion on binary Al‐Cu system (Compare wit...Figure 13.45 Effect of Mg back diffusion on binary Al‐Mg system (Compare wit...Figure 13.46 Crack susceptibility shown by transverse‐motion weldability tes...Figure 13.47 Mg‐Gd system: (a) phase diagram; (b) crack susceptibility curve...Figure 13.48 Grain boundary liquid: (a) dihedral angle; (b) distribution of ...Figure 13.49 Extensive bonding delayed, e.g. to (f _S)^1/2 > 0.98, by very smal...Figure 13.50 Binary Al‐Sn system: (a) phase diagram; (b) T‐(f _S)^1/2 cur...Figure 13.51 Solidification