High temperature hydrogen attack results from exposure to hydrogen at elevated temperatures and pressures. The hydrogen reacts with __________ in steel to produce _________, which cannot diffuse through the steel. The loss of carbides causes an overall loss in strength.
High-temperature hydrogen attack occurs when hydrogen at high temperatures and pressures reacts with carbides in steel to form methane. The methane cannot diffuse through the steel, which leads to a loss of carbides and, consequently, a reduction in the strength of the steel.
High-temperature hydrogen attack (HTHA) results from exposure of steels to hydrogen gas at elevated temperatures and pressures. Dissociated hydrogen atoms react with carbon and carbides in the steel to form CH4.