PSI - Issue 60

Vivek Srivastava et al. / Procedia Structural Integrity 60 (2024) 233–244 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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2. Materials and methods Chemical composition of XS steel was identified using inductively coupled plasma optical emission spectroscopy (ICP-OES) technique and is given in Table 1. Tensile properties (‘ASTM Standard E8: Test Methods for Tension Testing of Metallic Materials’, 2004) and micro-hardness (‘ASTM Standard E92 Vickers Hardness of Matallic Materials’, 1997) of this steel were experimentally determined and are given in Table 2. This steel exhibited a ferritic-pearlitic microstructure, consisting approximately 22 % pearlite (Fig. 1). Potentiodynamic corrosion behaviour was studied by Tafel method as per ASTM G59 (‘ASTM Standard G59 Test Method for Conducting Potentiodynamic Polarization Resistance Measurements’, 2003) . Tafel plot of XS steel is shown in Fig. 2, indicated that the corrosion current density in freely corroding (FC) or open circuit potential (OCP) condition was three orders of magnitude larger than in ICCP-protected condition (-800 mV). Table 1. Chemical composition of XS steel C Si Mn S P Cr Ni Cu Fe ≤ 0.12 0.8 - 1.1 05- 0.8 ≤ 0.04 ≤ 0.035 0.6 - 0.9 0.5 - 0.8 0.4 - 0.6 Balance

Table 2. Tensile properties and micro-hardness of XS steel Specified yield strength, Spec. YS (MPa) Yield strength, YS (MPa) Ultimate tensile strength, UTS (MPa)

Elongation to fracture (%)

Micro-hardness (Vicker’s hardness number)

390

444 ± 2

606 ± 3

26 ± 2

211 ± 8

Fig. 1. Ferritic (F) -pearlitic (P) microstructure of XS steel

Fig. 2. Tafel plot for potentio-dynamic corrosion behaviour of XS steel