Neutron diffraction is an important tool for residual stress measurement in welded structures. The calculation of stresses from measured lattice spacings generally requires the stress free lattice spacing a priori. For dissimilar metal welds common to nuclear reactor pipeline systems, the stress free lattice spacing is a complex function of position due to the chemistry and microstructure inhomogeneity in the weld region, and its experimental determination can be both time consuming and unreliable. An improved approach is developed to calculate the residual stress field without the use of stress free lattice spacing. Its applicability is examined and justified in two multipass dissimilar metal welds made of 304L stainless steel plate and nickel alloy 82 filler metal using different heat inputs. The spatial variation in stress free lattice spacing is qualitatively discussed using the weld metal dilution mechanism. The improved approach is shown to be simple and practical for residual stress determination in dissimilar metal welds.
MasubuchiK: ‘Analysis of welded structures: residual stresses, distortion, and their consequences’; 1980, New York, Pergamon Press.
4.
‘Standard test method for determining residual stresses by the hole-drilling strain-gage method’, ASTM E837-08, ASTM International, West Conshohocken, PA, USA, 2008.
5.
RiekelC: ‘The use of synchrotron radiation for materials research’, in ‘Analysis of residual stress by diffraction using neutron and synchrotron radiation’, (ed. FitzpatrickM E, LodiniA); 2003, New York, Taylor & Francis, 28–44.
6.
BrownTB, DaudaTA, TrumanCE, SmithDJ, MemhardD, PfeifferW: ‘Predictions and measurements of residual stress in repair welds in plates’, Int. J. Press. Vessels Pip., 2006, 83, 809–818.
7.
FicquetX, SmithDJ, TrumanCE, KingstonEJ, DennisRJ: ‘Measurement and prediction of residual stress in a bead-on-plate weld benchmark specimen’, Int. J. Press. Vessels Pip., 2009, 86, 20–30.
8.
de NovionCH: ‘The use of neutrons for materials characterization’, in ‘Analysis of residual stress by diffraction using neutron and synchrotron radiation’, (ed. FitzpatrickM E, LodiniA, ed); 2003, New York, Taylor & Francis, 3–27.
9.
SpoonerS: ‘Neutron residual stress measurement in welds’, in‘Analysis of residual stress by diffraction using neutron and synchrotron radiation’, (ed. FitzpatrickM E, LodiniA, ed); 2003, New York, Taylor & Francis, 296–318.
10.
PratiharS, TurskiM, EdwardsL, BouchardPJ: ‘Neutron diffraction residual stress measurements in a 316L stainless steel bead-on-plate weld specimen’, Int. J. Press. Vessels Pip., 2009, 86, 13–19.
11.
MurakawaH, BérešM, DaviesCM, RashedS, VegaA, TsunoriM, NikbinKM, DyeD: ‘Effect of low transformation temperature weld filler metal on welding residual stress’, Sci. Technol. Weld. Join., 2010, 15, 393–399.
12.
GoldakJA, AkhlaghiM: ‘Computational welding mechanics’; 2005, New York, Springer.
13.
TsaiCL, KimDS: ‘Understanding residual stress and distortion in welds: an overview’, in ‘Processes and mechanisms of welding residual stress and distortion, (ed. FengZ L, ed); 2005, FL, Boca Raton, Woodhead Publishing and CRC Press, 3–31.
14.
ZhangW, YangY.-P: ‘Development and application of on-line weld modelling tool’, Weld. World, 2009, 53, 67–75.
15.
HoldenTM: ‘Applications of neutron diffraction to engineering problems’, Proc. 12th Natl School on ‘Neutron and X-ray scattering’, Oak Ridge, TN, USA, June 2010, Oak Ridge National Laboratory.
16.
HoldenTM, SuzukiH, CarrDG, RipleyMI, ClausenB: ‘Stress measurements in welds: problem areas’, Mater. Sci. Eng. A, 2006, A437, 33–37.
17.
StaronP, KoçakM, WilliamsS:‘Residual stress distributions in friction stir welded Al sheets determined by neutron strain scanning’Proc. 6th Int. Conf. on ‘Trends in welding research’(
DavidS A, ); 2002, Pine Mountain, GA, ASM International, 253–256.
18.
WooW, FengZ, WangX.-L, AnK, HubbardCR, DavidSA, ChooH: ‘In situ neutron diffraction measurement of transient temperature and stress fields in a thin plate’, Appl. Phys. Lett., 2006, 88, 261903–261903-3.
19.
WithersPJ, PreussM, SteuwerbA, PangJWL: ‘Methods for obtaining the strain-free lattice parameter when using diffraction to determine residual stress’, J. Appl. Crystallogr., 2007, 40, 891–904.
20.
ElmerJW, WongJ, ResslerT: ‘Spatially resolved X-ray diffraction mapping of phase transformations in the heat-affected zone of carbon–manganese steel arc welds’, Metall. Mater. Trans. A, 2001, 32A, 1175–1187.
21.
BroussardJ, WhiteG, CrookerP: ‘EPRI welding residual stress validation program for dissimilar metal welds: a program overview’, Proc. Int. Conf. on ‘PWR materials reliability’, Colorado Springs, CO, USA, June–July 2010, EPRI.
22.
ZhangW, KimC.-H, DebRoyT: ‘Heat and fluid flow in complex joints during gas metal arc welding. Part II: application to fillet welding of mild steel’, J. Appl. Phys., 2004, 95, 5220–5229.
23.
PanneerselvamG, RajuS, JoseR, SivasubramanianK, DivakarR, MohandasE, AntonyMP: ‘A study on the thermal expansion characteristics of Inconel-82 filler wire by high temperature X-ray diffraction’, Mater. Lett., 2004, 58, 216–221.
24.
BoeufA, CricoS, CaciuffoR, RustichelliF, PomotI, UnyG: ‘Effects of M23C6 precipitation on the lattice parameter of AISI 304 stainless steel’, Mater. Lett., 1985, 3, 115–118.
