PSI - Issue 14

Vijay Sai et al. / Procedia Structural Integrity 14 (2019) 491–498 Ch. Vijay Sai/ Structural Integrity Procedia 00 (2018) 000–000

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The magnitude and spatial variation of peak temperature, is an important indicator of the development of eigen strain. From Fig. 5a, it is seen that the higher thermal diffusivity of P91, results in the temperature profile in P91 joint being steeper than SS304. A steeper distribution indicates greater restraint and thus greater eigen strain. It is also observed from Fig. 5a; the effect of P91 is greater than that of SS304 in governing heat transfer, in the dissimilar plate weld joint. Similar conclusions are inferred from Fig. 6a and Fig. 6b pertaining to the circumferential weld joints. In the dissimilar weld joints the decrease in temperature and increase in steepness on SS304 side is higher than the increase of temperature and change in steepness on P91 side, vis-à-vis their respective joints. This influences the eventual residual stress formation in the joints.

Fig. 5. (a) Peak temperature variation in plate weld joints; (b) Temporal variation of temperature at various locations of dissimilar plate joint.

Fig. 6. (a) Peak temperature variation in circumferential pipe weld joints; (b) Temporal variation of temperature at various locations of dissimilar circumferential pipe weld joint.