PSI - Issue 38

Nitish Shetye et al. / Procedia Structural Integrity 38 (2022) 538–545 Shetye et al. / Structural Integrity Procedia 00 (2021) 000 – 000

540

3

thicknesses. More details about the conceptual design, weld quality and the fatigue strength properties for these bogie beams can be found in (Stemp, 2012) and (Jonsson et al., 2011).

Table 1. Bogie beam web and flange thicknesses . A30 Original

A30 Optimized

Flange Thickness [mm] Web Thickness [mm]

15 10

12

5

Mass (m beam ) [kg]

38.8

25.6

3. Life Cycle Analysis Life-Cycle Analysis (LCA) is a methodology which aims at assessing the energy requirements during the lifetime of a product including production, use and end-of-life phases of the product. LCA also includes the end-of-life phase which accounts for the recycling and disposing energy and the energy credits which are obtained from recycling, which completes the circular flow of ene rgy. The total life-cycle energy for a bogie beam is given by: E LC = E ME + E SP + E BM + E UP + E EOL (1)

where E LC is the life-cycle energy, E ME is the material extraction energy, E SP is the steel production energy, E BM is the bogie manufacturing energy, E UP is the use phase energy and E EOL is the end-of-life energy.

3.1. Material extraction phase

Steps that were considered were mining the ore, screening, enrichment and pelletizing to make iron ore pellets for steel production. Both conventional and HYBRIT Steel require the same steps for the material extraction phase. The material extraction processes, and the energy associated with those processes can be seen in Table 2.

Table 2. Energy required for the resource extraction processes (LKAB, 2020). Material Extraction Steps Energy [GJ/tonne] Mining 0.040 Screening 0.006 Enrichment 0.058 Pelletizing 0.449 Logistics and Others 0.023 Total (E ME tonne ) 0.576

The energy required for the resource extraction for the bogie beam is given by Equation 2 and the actual energy consumption for the resource extraction for making the two designs of bogie beams can be seen in Table 3.

tonne

E ME = m beam E ME

/1000

(2)

Table 3. Material extraction energy for the two bogie beams.

Energy [MJ]

A30 Original

A30 Optimized

Conventional Steel

22.3 22.3

14.7 14.7

HYBRIT Steel