Some Aspects of the Stress Corrosion Testing of Austenitic, Martensitic, Ferritic-Austenitic and Ferritic Types of Stainless Steel by Means of the Slow Strain-Rate Method

Abstract

The stress corrosion cracking (SCC) susceptibility of six different types of stainless steel (AISI 304, 316 and 431, and Uranus 50, Orion 26-1, and Orion 28-2 from Creusot Loire) was tested in concentrated magnesium chloride (MgCl2) solutions by means of the slow strain-rate (SSR) method. The effects of strain rate, chloride concentration, testing temperature, electrode potential of the specimen, and the presence of inhibitors have been investigated. Test results are compared with literature data. The ferritic steel Orion 26-1, expected to be immune to SCC, was found to show some susceptibility in SSR tests. In the present SSR tests, some inhibitors were found to be completely effective in preventing SCC in MgCl2 solutions in concentrations considerably lower than reported in the literature for constant strain-type testing conditions.

Resistance of Ferritic FeCrAl Alloys to Stress Corrosion Cracking for Light Water Reactor Fuel Cladding Applications

“…At the beginning of this paper it was mentioned that ferritic Fe-Cr SS are highly resistant to SCC in chloridecontaining environments. [5][6][7][8][9][10][11][12] Testing showed that Fe-Cr SSs are also resistant to SCC in simulated high-temperature water reactor environments. [17][18]24 A 1974 screening study on the relative susceptibility to 288°C water of several types of SS showed that ferritic stainless such as E-brite † (UNS S44627), 19Cr-2Mo, and other experimental ferritic alloys were resistant to SCC in oxygenated water at 288°C.…”

“…Since the early studies some five or six decades ago, [5][6][7][8] the interest in the SCC resistance of ferritic SS in chloride solutions continued and newly optimized versions of ferritic SS were introduced into the market. [9][10][11][12] Ferritic Fe-Cr-Mo alloys are practical solutions to chloride-induced SCC problems in austenitic SS, and 18Cr-2Mo SS was recommended as replacement for austenitic Type 304 SS and 26Cr-1Mo SS as a replacement for austenitic Type 316 SS. 12 The resistance to chloride-induced SCC of ferritic SS could be a consequence of both (a) their bcc crystal structure and (b) the lack of Ni in their composition.…”