PDF《Alloy 690 Base Metal》

690 Base Metal Strategy

13 Double-cone compression specimens give very well defined strain contours EBSD of Double EBSD of Double- -Cone Compression of Alloy

182 Cone Compression of Alloy

182 Alloy

690 Base Metal Strategy

14 Misorientation map compared to FEM prediction of strain contours after application of geometric 0.23 compressive strain to double cone. EBSD Finite Element Modeling EBSD of Double EBSD of Double- -Cone Compression of Alloy

182 Cone Compression of Alloy

182 Alloy

690 Base Metal Strategy

15 0

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20 Distance from Left Side of Sample (mm) AMIS (degrees * 10) or FEM Strain (%)

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80 100 Hit Rate AMIS FEM Strain Hit Rate EBSD of Double EBSD of Double- -Cone Compression of Alloy

182 Cone Compression of Alloy

182 Alloy

690 Base Metal Strategy

16 Inverse Pole Figure C x orientation maps Sample MR2911-L3 longitudinal to weld direction 0.237 geometric strain EBSD of Double EBSD of Double- -Cone Compression of Alloy

182 Cone Compression of Alloy

182 Misorientation (strain) map Sample MR2911-L3 C Dendrite long axes parallel to compression axis Alloy

690 Base Metal Strategy

17 EBSD Characterization EBSD Characterization Given its proven capability, EBSD should be used to characterize a wider cross-section of welds and structures: ? HAZ and weld metal of std. planar welds ? HAZ and weld metal of std. circular (e.g., CRDM) welds ? uniformity of cold work and surface layers in base metals ? uniformity of deformation in banded microstructures Weld HAZ aligned SCC specimens should also be used, but: ? a planar interface is critical;

not all welds are suitable ? larger radius side-grooves give flexibility to crack plane ? must plan on only perhaps 33% of tests working well Alloy

690 Base Metal Strategy

18 SCC Response in Alloy

690 SCC Response in Alloy

690 Alloy

690 is not immune, but cracks appear to grow ........