PSI - Issue 23

Joakim Nordström et al. / Procedia Structural Integrity 23 (2019) 457–462 Joakim Nordström / Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 6: Fractographs of the Alloy 625 tested at RT and at CT: a) at RT, overview b) at RT, middle part, c) at RT, shear fracture, d) at CT, middle part (read line indicates merging line between two fractographs), e) at CT, middle part, f) at CT, shear fracture.

4. Conclusions

 Deformation twinning in Alloy 625 can occur when it is deformed at cryogenic temperature or to very large plastic strain, which will cause TWIP behavior increasing both strength and elongation.  TWIP can endorse large homogenous plastic deformation or elongation, but relatively small necking elongation and contraction.  Pre-formed deformation twins will become obstacles for dislocation slip and cause pile-up that leads to local stress concentrations and eventually necking.

Acknowledgements

We, the authors, gratefully acknowledge Sandvik Materials Technology for the financial support of this job.

References

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