PSI - Issue 23

Aleš Materna et al. / Procedia Structural Integrity 23 (2019) 425–430 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

430

6

, ( )

Fig. 6 Numerically determined values of equivalent logarithmic plastic strain for specimen with 20% reduction of thickness

0 1000 2000 3000 4000 5000

measurement FEM

HIT [MPa]

-8 -6 -4 -2

0

2

4

6

8

Distance from surface center [mm]

Fig. 7 Comparison of indentation hardness profiles along the specimen ’s width obtained from measured values of HV3 and from estimated values evaluated numerically using combination of 3D and 2D FEM

4. Conclusions The experimental measurement of the effect of annealing at 700 °C on mechanical properties of undeformed and cold-deformed 08Ch18N10T austenitic stainless steel as well as the numerical simulation of the applied cold deformation process led to the following main conclusions: 1. Annealing slightly increased hardness of undeformed 08Ch18N10T steel whereas the hardness of cold-deformed steel with both thickness reductions 10 and 20 % slightly decreased. This was observed even after 1 hour of annealing. The effect of further annealing is unclear since the dependence of hardness on annealing time is not monotonous. 2. Hardening of rectangular samples by their compression led to heterogeneity of plastic strains and, therefore, to uneven distribution of hardness on spec imen’s surface. For proper evaluation of the effect of annealing on hardness of steel, one should avoid thin region in the middle of the sample during the hardness measurement.

Acknowledgement

This work was supported by the Technology Agency of the Czech Republic under the project No. TH02020565.

References

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