Corrosion Fatigue Numerical Model for Austenitic and Lean-Duplex Stainless-Steel Rebars Exposed to Marine Environments

Abstract

Steel rebars of structures exposed to cyclic loadings and marine environments suffer an accelerated deterioration process by corrosion fatigue, causing catastrophic failure before service life ends. Hence, stainless steel rebars have been emerging as a way of mitigating pitting corrosion contribution to fatigue, despite the increased cost. The present study proposes a corrosion fatigue semiempirical model. Different samples of rebars made of carbon steel, 304L austenitic (ASS), 316L ASS, 2205 duplex (DSS), 2304 lean duplex stainless steels (LDSS), and 2001 LDSS have been embedded in concrete and exposed to a tidal marine environment for 6 months. Corrosion rates of each steel rebar have been obtained from direct measurement and, considering rebar standard requirements for fatigue and fracture mechanics, an iterative numerical model has been developed to derive the cycles to failure for each stress range level. The model resulted in a corrosion pushing factor for each material, able to be used as an accelerating coefficient for the Palmgren-Miner linear rule and as a performance indicator. Carbon steel showed the worst performance, while 2001 LDSS performed 1.5 times better with the best cost-performance ratio, and finally 2205 DSS performed 1.5 times better than 2001 LDSS.

Neutronographic Analysis of Load Partitioning and Micro Residual Stress Development in Duplex Stainless Steels

“…Duplex stainless steels generally have good mechanical properties that are expressed in their high strength in combination with good ductility. In addition, duplex stainless steels often have better corrosion resistance than conventional austenitic steels [1][2][3]. Therefore, duplex stainless steels are particularly used in the chemical industry, petrochemistry, seawater desalination plants, and offshore technology [4,5].…”

The Weldability of Duplex Stainless-Steel in Structural Components to Withstand Corrosive Marine Environments

“…For that purpose, additional strength tests are required to ensure the welding is performing at least as good as the base materials. Besides, cyclic loadings can cause the appearance of such macrodefects, even later unleashing corrosion fatigue problems [33,34], and even permanent tensions can cause development of stress corrosion cracking if weld bead suddenly changes geometry or accelerates corrosion fatigue deterioration [35,36].…”

Analysis of Phase-Specific Strain Pole Figures for Duplex Steels under Elasto-Plastic Uniaxial Tension—Experiment vs. EPSC Modelling

“…For this purpose, for each measurement the sample was rotated in total by 90° in the φ direction. Thus, for each orientation of the strain PF, a phase-and lattice-plane-specific strain can be calculated according to Equation (2).…”

“…In addition, duplex stainless steels often have better corrosion resistance than conventional austenitic steels, which makes them attractive for applications in, i.a. the chemical and petrochemical industries, in seawater desalination plants and in offshore technology [1][2][3][4][5]. In principle, when producing metallic technical components through processes where plastic deformation and/or thermal energy are introduced, it can be assumed that phase-specific crystallographic textures and/or phase-specific residual stress (RS) states are introduced or affected.…”