Study on cathodic reaction control efficiency by low alloy steels

Akashi, Masatsune*; Fukaya, Yuichi*; Asano, Hidekazu*

JNC TJ8400 2000-014, 22 Pages, 2000/02

JNC-TJ8400-2000-014.pdf:0.75MB

Difference of hydrogen generation phenomena on the surface of the Steels were not observed between carbon steel, atmospheric corrosion resisting steel and 5%-Ni steel. Rust layer was formed on these three-type of steels by steam oxidation method. And the chemical composition of the rust for the steels were basically two(2) layers structure for the previous two steels as hematite(FeO) based for the outer layer and magnetite(FeO) based for the inner layer. And for the last steel, it had three(3) layer in the rust as hematite(FeO) based for the outer layer, magnetite(FeO) based for the intermediate layer and Ni based layer for the inner layer. These steels showed mostly same Tafel gradient in their cathodic polarization curves compare with that for no rust specimens. However, the exchange current density which reaction is assumed as a hydrogen generation reaction was largely increased. The cathodic reaction for each steels whose surface is covered by magnetite layer might be accelerated, then the corrosion rate was considered as accelerated, too.

Modification of graphene by the photoemission-assisted plasma, 1; Raman analysis

Fukuda, Akito*; Takabayashi, Susumu*; Naito, Haruhiro*; Tanaka, Shuto*; Yamaguchi, Hisato*; Ogawa, Shuichi*; Takakuwa, Yuji*; Tsuda, Yasutaka; Yoshigoe, Akitaka

no journal, , 

Although modification or chemical modification is necessary in graphene applications, the damage due to the modification processes is a serious problem. In this conference, it is reported that the defects confirmed by D-band peak in Raman spectroscopy can be selectively controlled by using the Townsend discharge region of photoemission-assisted plasma, which can prevent ion damage.

Modification of graphene by photoemission-assisted Townsend discharge plasma

Fukuda, Akito*; Naito, Haruhiro*; Tanaka, Shuto*; Yamaguchi, Hisato*; Ogawa, Shuichi*; Takakuwa, Yuji*; Tsuda, Yasutaka; Yoshigoe, Akitaka; Takabayashi, Susumu*

no journal, , 

Graphene is a two-dimensional material. Its outstanding characteristics such as gas-barrier properties have been remarked. To improve these characteristics or find new one, its modification is indispensable; however, the existing methods may destroy or reduce properties: implantation, adsorption, and chemical modification. We have been using low-energy ion attack of photoemission-assisted Townsend discharge (PATD) plasma. In conventional radio-frequency discharge plasma, a sheath electric field may cause severe damage to graphene. Because of the displacement current, both current and voltage are difficult to measure independently and precisely. Power in watt, which is a product of current and voltage, is used as a variable. However, the current is an extensive variable and is a factor of kinetics of chemical reactions. The voltage is an intensive variable and is a factor of thermodynamics. PATD is a DC plasma. Thus, we can expect precisely-controlled graphene by PATD.