Stainless steels: Passive film composition, pitting potentials, and critical chloride content in concrete

Abstract

Stainless steel reinforcing bars show excellent corrosion resistance in concrete structures exposed to harsh environments. Only a little information on the surface chemistry of these materials in alkaline media is available. This study reports the X-ray photoelectron spectroscopy surface analytical results (thickness, composition of the passive film and of the interface beneath the film) obtained on black steel, FeCr alloys, DIN 1.4301, DIN 1.4462 and the nickel-free DIN 1.4456 after exposure to alkaline solutions simulating concrete. The pitting potentials of the steels could be related to the Cr(III)oxy-hydroxide and Mo(VI) content in the passive film. C crit , the critical chloride content for corrosion initiation in concrete, necessary for life-time predictions, can be determined only with time-consuming tests, especially for high-alloyed stainless steel. This study reports a correlation between C crit in concrete (made with CEM II-A/LL and CEM I) and the pitting potential for carbon steel, Fe12%Cr alloy, DIN 1.4301, and DIN 1.4571 stainless steels. This could allow, for the first time, a quantitative estimation of C crit for stainless steel in concrete based on short-term solution tests. K E Y W O R D Scritical chloride content, pitting, stainless steels, XPS surface analysis, reinforced concrete

Stainless Steels as Sustainable Solution for Concrete Reinforcement - From Laboratory to Practice

“…5 are also pitting potentials of three lean duplex steels determined in Ca(OH)2 solution with the same chloride concentration [13]. A similar relation between Epit on the PREN was reported for higher alloyed stainless steels in 0.1 M NaOH solution with 1 -5 M NaCl added [9]. [7,14,15].…”

“…5, Epit increases linearly with the pitting resistance equivalent number (PREN) calculated as PREN = %Cr + 3.3*%Mo (Fig. 5, see also [9]). Included in Fig.…”

The Application of Electrochemical Noise for the Study of Metal Corrosion and Organic Anticorrosion Coatings: A Review

“…Part of the current promoted the development of pitting nuclei, and the other part promoted the repair of the passivation film. [50] Due to the destruction and repair of the passivation film, the corrosion potential fluctuated, which led to the generation of flicker noise. [51] For the steel passivated by sodium phosphate, the noise resistance R n obtained from the electrochemical noise and the polarization resistance R p obtained from the linear polarization in the NaCl solution were in well agreement (Figure 7).…”

Influence of inhibitors on the corrosion behavior of the X5CrNi18 10 stainless steel‐welded joint

“…The film formation depends on the presence of chromium in stainless steel. Elsener et al [ 1 ] have recently analyzed the composition of passive film formed in chloride‐containing solutions on several types of stainless steel.…”