Microstructural analysis of candidate steels pre-selected for new advanced reactor systems

Positron annihilation studies on 9Cr reduced activation ferritic/martensitic steels

“…3 Results and discussion Optical microscopy and SEM revealed typical tempered martensite structure, stable upto 1073 K, with a few coarse carbides similar to the reported earlier [4]. However, beyond 1273 K, martensite structure is seen by SEM as shown in Fig.…”

Study of microstructure and microtexture of modified 9Cr–1Mo steel subjected to high deformation

“…The average diameter of coarse packet boundary carbides is about 150 nm where as fine carbides are 30 nm. The martensite packet width is about 1.5 lm for the N&T steel consistent with other reports [11][12][13][14][15]. Fig.…”

“…The coarse carbides are of M 23 C 6 type and are enriched in Cr [12][13][14][15]. These carbide precipitates generally decorate across the prior austenite, lath, sub-grain and cell boundaries but rarely found with dislocations within the matrix [11]. There are also some fine globular carbides (shown by thin arrow) with diameter of about 20-30 nm across the packet boundary as well as within the packet.…”

“…There are also some fine globular carbides (shown by thin arrow) with diameter of about 20-30 nm across the packet boundary as well as within the packet. These vanadium enriched carbides belong to the MX type [11][12][13][14][15], but their distribution throughout the matrix is more or less uniform in nature [12]. The average diameter of coarse packet boundary carbides is about 150 nm where as fine carbides are 30 nm.…”

“…It is well known that deformation may lead to development of crystallographic texture [7]. As the integrity of the clad tube during its service is of paramount importance, a sound knowledge about its microstructure and microtexture, both of which govern the material's properties, is necessary [7][8][9][10][11][12][13][14][15]. Literature reports on the effect of heavy deformation (up to 88% of cold rolling) on microstructural and microtextural changes in mod.9Cr-1Mo steels is very scarce; hence this paper presents the results of detailed study on evolution of microstructure and microtexture subjected to deformation by cold rolling to the extent of 88% of thickness reduction.…”