Study on Stress Corrosion Cracking Mechanism of Steel Wires with Different Strength Levels

In civil engineering, stress corrosion cracking (SCC) is a common cause of premature failure in steel wires, and effective solutions are currently limited. Investigating the SCC behavior of steel wires with different strength levels is crucial for understanding its fracture mechanism and developing potential solutions. This study examines the SCC behavior of wire rods with three strength grades (Steel A, B, and C) through stress corrosion experiments. The results show that high-strength wire rods have smaller pearlite interlamellar spacing. Steel C has the highest tensile strength (2303 MPa), while Steel A has the lowest (1830 MPa). Regarding stress corrosion sensitivity, the SCC mechanism of Steel C is dominated by hydrogen embrittlement, while Steels A and B primarily exhibit anodic dissolution as the cracking mechanism. Although Steel C has the smallest pearlite interlamellar spacing and superior corrosion resistance, its SCC failure time is the shortest due to hydrogen embrittlement. In contrast, for the anodic dissolution cracking mechanism, Steel B has a smaller pearlite interlamellar spacing, which enhances its corrosion resistance, and exhibits higher local stress stability due to its higher strength, resulting in the best SCC resistance (failure time: 3.81 h). This study reveals the synergistic effects of microstructure and strength on the SCC behavior of wire rods, offering theoretical guidance for the application of high-strength wire rods.