Abstract
Hydrogen-induced disbonding of austenitic stainless steel cladding was investigated. The used test specimen was made from the heavy section 2 1/4Cr-1Mo steel plate weld-clad using type 309 strip with 75 mm width and type 347 strip with 150 mm width. And it was heated at 455°C in autoclave containing high pressure H2 for hydrogen charging.
The results indidate that (1) the delayed cracking occurs when the specimen is rapidly cooled from hydrogen charging temperature, but it cannot occur above 100°C, (2) this type of cracking takes place in grain boundaries of cladding adjacent to the fusion line, (3) the susceptibility to cracking decreases by application of post-heating or by reducing the rate of cooling after hydrogen charging, (4) numerical analysis applied to hydrogen distribution may explain the behaviour of cracking.
