PSI - Issue 35

Andreas Seupel et al. / Procedia Structural Integrity 35 (2022) 10–17 A. Seupel et al. / Procedia Structural Integrity 00 (2021) 000–000

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Table 1. Thermodynamic parameters. Component

Parameter

Unit

Value

clamp (42CrMo4)

E

MPa

210000

-

0.3

ν

1

11.1 · 10 − 6 7720

K −

α inst

kgm − 3 Jkg − Wm −

ρ

1 K − 1

470 42.6

c

1 K − 1

λ th

punch (WC-Co)

E

MPa

650000

-

0.22

ν

1

5.2 · 10 − 6 14800

K −

α inst

kgm − 3 Jkg − Wm −

ρ

1 K − 1

225

c

1 K − 1

83

λ th

specimens (X3CrMnNi 16-6-6)

E

MPa

192000

-

0.24

ν

1

5 · 10 − 6 7780 455.57

K −

α inst

kgm − 3 Jkg − Wm − Wm − Wm −

ρ

1 K − 1

c

1 K − 1

15

λ th

2 K − 1 2 K − 1

free boundaries, contact surfaces

h t (convection air)

8

h c (gap conductance punch)

2000

1 . 5

1 . 5

martensite volume fraction z 0 . 25 0 . 5 0 . 75 1 1 . 25 σ true stress | σ | in GPa 213 K 293 K 333 K ∗ 373 K

213 K 293 K 313 K ∗ 333 K ∗ 373 K

martensite volume fraction z

1 . 25

1

0 . 25 true stress σ in GPa 0 . 5 0 . 75

σ

z

z

0 . 2 0 . 4 0 . 6 0 . 8 1

0 . 2 0 . 4 0 . 6 0 . 8 1

0

0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0

0

0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0

0

0

true strain

true strain | |

Fig. 2. Stress-strain-curves and martensite evolution of quasi-static (a) tensile and (b) compression tests: experiments–dotted lines and symbols, simulations–solid lines. *–predictions. Experimental data from Wolf (2012).

phenomenon. Friction is neglected for compression tests. Heat conduction and heat transfer by convection via the clamping systems and to the environment are taken into account. The testing setups are sketched in Fig. 1. All ther modynamic parameters are summarized in Tab. 1. The simulated martensite content is measured in the highlighted area via an averaging procedure described in Pru¨ger et al. (2011, 2014). Temperature increase during the test has been recorded with help of thermocouples (TC) at the marked positions.

4. Results and discussion

The parameters of the hardening model have been determined by fitting the stress-strain-curves of tensile and compression tests under quasi-static conditions at temperatures 213 K, 293 K and 373 K (technical strain rate ˙ t =