PSI - Issue 57

Kaushik Iyer et al. / Procedia Structural Integrity 57 (2024) 469–477 Kaushik Iyer, et.al. / Structural Integrity Procedia 00 (2019) 000 – 000 using = / , Where v is the pass velocity of the automated HFMI treatment (60 cm/min), and L weld is the weld length. Furthermore, in the as-welded sample, the cycle time to produce 1 sample was assumed to be the welding process time while the cycle time of the HFMI treated sample can be assumed to be the summation of the welding process times and the PWT process times. Additionally, the indirect costs such as capital investment, and the direct costs such as the material costs were combined according to, =∑ + (3) Where is the production cost per part and is the production volume. 3.4. Use-phase The welded samples analyzed in this study were assumed to be integrated into a representative welded box to be integrated into a crane hoist. The accumulated use-phase cost can be considered as a direct function of fatigue life and the operational hours. As derived from (Hagnell, et al. 2021), the sample was assumed to be undergoing 120 load cycles in a day for 250 days a year. Furthermore, the crane was assumed to be operating with a 200-kW motor for hoisting containers. Furthermore, according to the safety guidelines, an annual inspection and maintenance cost of 625€ was added to the operational electricity costs. Therefore, the use-phase cost can be calculated through, = € ∗ ∗ + (4) Where AOH is the annual operating hours and is the motor power in kW. 3.5. End-of-Life Steel is a highly recyclable material with most of the steel products being made of recycled material and the industry possessing a robust End-of-life (EOL) retrieval and recovery supply chain. Therefore, to assess the EOL costs, a retrieval rate of 90% rate can be assumed. It can also be assumed that the scrap from the EOL component will fetch a price of 0.21 €/kg . 4. Results and Discussion The life cycle costs of the as-welded (AW) and HFMI treated samples as evaluated for a production volume of 85000 PPY and a weld length of 500 mm is given in Table 4. 6

474

Table 4: Life-cycle Costs

6mm

12mm

Costs (€/part)

AW

HFMI treated

AW 10.4 49.6

HFMI Treated

Material

5.1

5.1 790

9.2

Production Use-phase

35.7

1151.4 627500

627,500

627,500

627500

EOL

-0.97

-0.97

-1.94

-1.94