Modeling of corrosive atmospheres for evaluation of the efficiency of volatile inhibitors

A method of modeling aggressive atmospheres used for different tests in corrosive environments close as possible to actual full-scale conditions is proposed. The method provides simulation of air atmospheres containing gaseous corrosion stimulants (CS) as microcomponents of air. The content of SCs in such atmospheres (both separately and together) can be set and maintained at an unchanged level within a wide range for as long as desired. The method is based on Henry’s equation characterizing concentration of the gas dissolved in a liquid phase as a function of the gas partial pressure in the equilibrium gas medium with allowance for the solubility of the corrosion stimulants in water in conditions under consideration. The procedure is easy to use and does not require long special training. Samples of corrosion stimulants NH3, CO2, and H2S are considered. Experimental results characterizing the corrosion rate of St3 carbon steel and copper with one or several CS simultaneously present in air atmosphere, as well as data on the efficiency of volatile inhibitors of «IFHAN» series under similar conditions are presented.

In situ time-lapse synchrotron radiation X-ray diffraction of silver corrosion

In order to study the initial corrosion processes of silver in the presence of corrosive gases in situ time-lapse XRD experiments were performed. The data collected using a newly combined environmental cell/gas flow set up introduces a set of highly useful tools for scientists to study time-lapse gaseous corrosion at ambient temperature and pressure.

ELECTRALLOY ALLOY ECHX

Electralloy ECHX is a solution-strengthened, nickel-base, high-performance alloy providing excellent resistance to high-temperature gaseous corrosion, coupled with good strength and stress rupture properties up to 1205 deg C (2200 deg F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-678. Producer or source: Electralloy, a Division of G.O. Carlson Inc.

ELECTRALLOY EC625

Electralloy EC625 is a solution-strengthened, nickel-base, high-performance alloy providing excellent resistance to both high-temperature gaseous corrosion and to aqueous corrosion, coupled with good strength and stress rupture properties up to 982 deg C (1800 deg F). This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-640. Producer or source: Electralloy, a Division of G.O. Carlson Inc.

Geochemical Processes at the Carbon steel/bentonite Interface in Repository Conditions

The Deep Geological Repository (DGR) is currently the most accepted management option for the isolation of high level radioactive wastes. The DGR is based on a multibarrier system, which will limit releases of mobile radionuclides to the biosphere. In the design of the repository the spent fuel is encapsulated in canisters of carbon-steel. The space between the canister and the host geological formation will be filled with bentonite buffer clay. Under the prevailing conditions in a DGR, both localized and generalized corrosion phenomena are possible.Corrosion of the canister will result in formation of solid and gaseous corrosion products, which can influence the behaviour of both the canister and the bentonite. Many studies have been carried out in order to improve the knowledge on the reactivity of these barriers. Most of them have focused on the mineralogical alteration of the bentonite as a function of temperature, time, iron/clay and liquid/rock ratio in batch conditions. The aim of this study is to provide experimental evidences, at repository conditions, on chemical and mineralogical changes during the canister-compacted bentonite interaction: determination of secondary minerals and their alteration reactions, the advance of the corrosion front in the compacted bentonite, and changes in porosity, permeability and cation exchange capacity.