Interface Characteristics and Properties of a High-Strength Corrosion-Resistant Stainless Steel Clad Rebar

Abstract

This paper aims at manufacturing stainless steel clad (SSC) rebars by metal deposition and a hot rolling method as well as characterizing its interface features and mechanical properties. The interface of the SSC rebar is relatively flat and clean, exhibiting a metallurgical bonding state at the microscale. Decarburization occurred at the interface in the carbon steel side of the SSC rebar. The diffusion of C, Cr, as well as Mn was measured across the interface of the SSC rebar, and the diffusion distance of Cr and Mn was found at 32 µm and 25 µm, respectively. The Vickers hardness testing in the transition zone of the SSC rebar near the carbon side showed 545 HV0.2 due to the martensite phase formed by the diffusion of key elements C, Cr, and Mn. The microstructure in the transition zone near the stainless steel reveals the duplex structure of martensite and ferrite. The carbide precipitations were observed near the interface, both in the transition zone and in the base metal of the stainless steel zone. The yield strength, tensile strength, and elongation of the SSC rebar were found as 423 MPa, 602 MPa, and 22%. No macroscopic crack was observed after the positive or negative bending tests.