Ferritic-martensitic steels for fission and fusion applications

New insights into the oxidation mechanisms of a Ferritic-Martensitic steel in high-temperature steam

“…High Cr content Ferritic-Martensitic (F-M) steels, typically ranging from 9 to 12 weight percent Cr, were developed since the early 1930s, originally for applications in the petrochemical industry, and later for the aerospace sector and conventional fossil fuel power generation units [1][2][3][4][5]. Due to the discovery of the phenomenon of irradiation-induced void swelling in austenitic alloys at the end of 1960s [6], F-M steels have also been used to partially replace austenitic alloys in the nuclear industry due to their excellent resistant to void swelling under irradiation conditions [1].…”

“…High Cr content Ferritic-Martensitic (F-M) steels, typically ranging from 9 to 12 weight percent Cr, were developed since the early 1930s, originally for applications in the petrochemical industry, and later for the aerospace sector and conventional fossil fuel power generation units [1][2][3][4][5]. Due to the discovery of the phenomenon of irradiation-induced void swelling in austenitic alloys at the end of 1960s [6], F-M steels have also been used to partially replace austenitic alloys in the nuclear industry due to their excellent resistant to void swelling under irradiation conditions [1]. A combination of low cost, good high-temperature strength, high stress corrosion cracking resistance, and low void swelling under irradiation, have contributed to very successful service records in the industries mentioned above, especially in steam-generating power plants, in which the high-temperature steam acts as a heat transfer medium and is very corrosive to the structural materials [2,5].…”

Microstructural understanding of the oxidation of an austenitic stainless steel in high-temperature steam through advanced characterization

“…where X is the thickness of the internal oxide layer; 1 (3) is the atomic fraction of dissolved oxygen at metal surface; 1 is the diffusivity of oxygen in the base metal; 6 (1) is the atomic fraction of solute metal in bulk alloy; v is the number of oxygen ions per B ion in solute metal oxide BO v . Since the internal oxide in the present study is FeCr 2 O 4 , v is calculated to be 4/3.…”

“…For many decades, due to their low cost, good mechanical properties, and high corrosion resistance in high-temperature environments, high Cr ferritic-martensitic (F-M) steels, typically ranging from 9 to 12 weight percentage of Cr, have been widely used as heat-resisting materials in the energy generating systems, in which water is used as heat-transfer medium [1][2][3][4][5]. To achieve greater thermal efficiencies and reduce emissions, the advanced energy generating systems, such as supercritical water reactors and ultra-supercritical fossil fuel power-generating units, are designed to operate at ever higher temperatures (>600ºC).…”

“…For example, the progressive reduction of heat transfer by thickening oxides can lead to over-heating and failure, and exfoliation of these oxides can result in blocking of tubes or, if the oxide fragments are transported in the steam, erosion of the steam turbine [2]. Despite the high-temperature corrosion of F-M steels has been extensively studied [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], effective remedy solutions have not be developed, especially in the environments containing water vapour, which significantly limits the application of the F-M steels in the high-temperature aqueous environments.…”