PSI - Issue 71

Poshadri Chathri et al. / Procedia Structural Integrity 71 (2025) 309–316

311

Table 1: SS304 composition (Liu et al., 2023).

Element

C

Si

Mn 2.1

P

S

Cr 18

Ni

Fe

Weight (%)

0.08

0.95

0.045

0.03

9.1

Bal.

2.1. Material Properties and Model Specifications The mechanical properties of commercially available SS304 stainless steel were obtained from uniaxial tensile tests conducted on three sets of specimens along the rolling direction, as reported by (Liu et al., 2023). The determined material properties are as follows: a density of 7.8×10 − 9 kg/mm 3 , a modulus of elasticity (E) of 200 GPa, a yield strength of 370.96 MPa, an ultimate tensile strength of 935.45 MPa, and a Poisson's ratio (ν) of 0.3.

Table 2: SS304 Mechanical properties (Liu et al., 2023).

Property

Value

Density (kg/mm3)

7.8×10 − 9

Modulus of elasticity (E) (GPa)

200

Yield strength (MPa)

370.96 935.45

Ultimate tensile strength (MPa)

Poisson's ratio (ν)

0.3

Fig. 2. shows randomly generated pits created using MATLAB, following ASTM G46-21 guidelines. Based on pit shape and depth, ASTM G46-21 classifies seven types of pits representing various corrosion stages, as seen in Figure 3a. This study mainly focuses on pit shapes and orientations for all aspect ratios on the dogbone specimen Figure 3b, as detailed in Table 3. Randomly placed spherical and different shaped pits, including wide shallow, elliptical, horizontal grain attack, and narrow deep pits, were generated with inline and random orientations, adhering to ASTM G46-21 specifications. These are based purely on numerical simulation which does not consider any material defects. The MATLAB simulation parameters replicate the randomness and variability of actual corrosion phenomena.

a Random Spherical pits with inline orientation f. Different shapes of pits inline sectional view Fig. 2 . Different types of orientations of randomly generated spherical pits and different shapes of pits with sectional views. b. Random Spherical pits with random orientation c. Random different shapes of pits with inline orientation d. Random different shapes of pits with random orientation e. Spherical shapes of pits inline sectional view