Example: B-Pillar Production

This example is based on the process description in [2] . It is for demonstration of the capabilities of EHTOS.PeNALPS and the results are not validated yet. Fig. 9 shows the process which consists of the following 4 steps:

1. Blanking

2. Heating

3. Forming and quenching

4. Trimming

Fig. 9 Direct Press hardening process chain [3]

The model built from this description is shown in Figure 2.

Fig. 10 Direct Press hardening process chain [2]

Capacity

The material flow parameters are determined based on the weight of a single b-pillar and the turnover times of the Forming and quenching.

It is assumed that the B-Pillar has a weight of 6kg. This assumption is based on the reported weight of a standard design in [4] which was 5.21 kg

The turnover times are used from [3] . The transfer from the oven takes 6 seconds and the press hardening 30 seconds

It is assumed that transfer from the forming and quenching step also takes 6 seconds. This sums up to to a turnover time of 42 seconds. This leads to capacity of 6 kg/42 seconds or 0.51 t / h

It is assumed that the other machines have the capacity to allow continuous production

Energy Demand

Meza-García et. al. [3] provides theoretical energies for 300 seconds of operation.

\[ E_{theo, heating} = 1867 kWs \]

\[ E_{theo,forming} = 17503 kWs \]

These are converted to real energies using the provided efficiency of 0.22:

\[ E_{real,heating} = 8.44 MJ \]

\[ E_{real,forming} = 79.559 MJ \]

Because these values are provided for 300 seconds of operation, they muss be converted to be mass specific to the product. The specific energy demands are calculated by

\[ E_{heating_mass}= \frac{E_{real,heating}}{300 s * 0.51 t/h}=198.61 MJ/t \]

\[ E_{forming_mass}= \frac{E_{real,forming}}{300 s * 0.51 t/h}=1871.98 MJ/t \]

For blanking and trimming no energy values are provided thus they are assumed to be:

\[ E_{real,blanking} = 0.2 * E_{forming_mass}= 374.396 MJ/t \]

\[ E_{real,trimming} = 0.3 * E_{forming_mass} = 561.594 MJ/t \]