PSI - Issue 14

Digendranath Swain et al. / Procedia Structural Integrity 14 (2019) 337–344 Swain et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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good agreement with the small magnitude of strains measured therein as compared to sample-H3. It was also seen that the direction of major principal RS after heat treatment was arbitrary on the xz and yz surfaces unlike it was along the z-direction before heat treatment. The comparison of surface RS in sample-H3 (Fig. 5b) shows that the RS on xz sides were compressive and xy-top layer were tensile. An opposite behaviour was seen at these surfaces in non-heat treated condition (sample-V3, Fig. 4). This means that wherever tensile stresses were observed before heat treatment altered to compressive and vice versa. This information is useful to understand the RS behaviour on the yz side of sample-V3 without heat-treatment. The RS distribution in Fig. 5a looks alike to the distribution at xy top surface in Fig. 5b. Hence, it is expected that the yz sides would have similar RS distribution as xy top side. However, since such measurement was not carried out, it needs to be confirmed with further experimentation.

Fig. 5. Principal RS vs depth estimated on (a) yz1 and yz2 surfaces of sample-V3 after heat treatment, (b) on xz and xy to surfaces of sample H3, (c) strain data on xz surfaces before (legends in box in secondary axis) and after heat treatment, and (d) RS on xz sides of sample-V3.

Fig. 6. (a) Comparison of strains measured on the xy top layers of samples -V3 (without heat treatment) and H3 and (b) comparison of principal RS on the xy top layer of samples V3 and H3. The secondary axis in (b) corresponds to RS in H3 (legends in box).

It must be noted that there was no space available on the xy top-side of sample-V3 to take measurement; hence no RS data could be obtained there after heat-treatment. The strain data reported in Fig. 6a shows the effect of heat-