21/4Cr-1 Mo鋼の水素アタックにおよぼす炭素の影響
1985 年 71 巻 14 号 p. 1639-1646
詳細
1985 年 71 巻 14 号 p. 1639-1646
Susceptibility to hydrogen attack of 2 1/4 Cr-1 Mo steel base metals and those simulated weld heat affected zone (HAZ) was investigated. Namely, tensile properties and a growth behavior of bubble cavities in the steels containing 0.05, 0.10 and 0.17% carbon were evaluated after an exposure to hydrogen at temperatures 200 to 650°C under a pressure of 300 kgf/cm2.
The steel which contained 0.17% carbon exhibited a remarkable deterioration in reduction of area at an earier period of the hydrogen exposure and a more rapid growth rate of bubble formation along grain boundaries than the steels contained 0.05 and 0.10% carbon. It was presumed that M3C carbides densely precipitated along the grain boundaries played a role to accelerate the growth rate of bubble formation during a hydrogen exposure, especially in the simulated HAZ material.
Incubation periods determined by the drop of reduction of area demonstrated an apparent linear decrease as increasing the carbon content. An activation energy was found to be 24 220 cal/mol in hydrogen attack of the 0.17% carbon containing steel.
