1-20 of 61 Search Results for

Microcracking

Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c0048845
EISBN: 978-1-62708-229-7
... Abstract The maximum life of base-loaded headers and piping is not possible to be predicted until they develop microcracking. The typical elements of a periodic inspection program after the occurrence of the crack was described extensively. Cracks caused by creep swelling in the stub-to-header...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001682
EISBN: 978-1-62708-229-7
... fatigue cracks in a bellows convolute. One such crack was recently shown to have initiated from a weld heat-affected zone liquation microcrack. The crack, initially open to the outer surface of the rolled and seam welded cylindrical bellows section, was closed when cold forming of the convolutes placed...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001473
EISBN: 978-1-62708-229-7
... notch-sensitive and liable to rupture in a brittle manner. Discontinuities were present in the rims formed by the drain holes drilled in their abutting faces, and possibly enhanced by the stress-raising effect of microcracks in the smeared metal at their surfaces It is probable that the load reached a...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001776
EISBN: 978-1-62708-241-9
... investigation revealed that the reason for the fracture was the presence of large carbides at the grain boundaries and in the grain matrix. This led to the formation of microcracks that propagated along the grain boundaries under in-service working forces. It is also believed that the precipitation of carbides...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001786
EISBN: 978-1-62708-241-9
...) revealed areas of damage due to rubbing with evidence of cleavage fracture on the unaffected surfaces. The results of stress analysis indicated that repeated reversals of the spindle produced stresses exceeding the fatigue limit of the shaft material. These stresses led to the formation of microcracks in a...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001839
EISBN: 978-1-62708-241-9
... surfaces revealed a brittle intercrystalline mode of fracture with typical manifestations of clear grain facets. Branched and discrete stepwise microcracks were also found along with unusually high levels of residual hydrogen. Mechanical tests revealed a marked loss of tensile ductility in the defective...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001840
EISBN: 978-1-62708-241-9
... shear strength significantly, causing the cladding process to fail. The findings reveal the decisive role of plastic strain localization and the associated development of microcracks in cladding failures. An attempt is thus made to determine the optimum cladding parameters for the materials of interest...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001844
EISBN: 978-1-62708-241-9
... combined with the observation of intergranular fracture surfaces and the presence of secondary microcracks in the case layer point to hydrogen embrittlement as the primary cause of failure. It is likely that hydrogen absorption occurred during the gas carburizing process. cylindrical spiral gear...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001113
EISBN: 978-1-62708-214-3
... was determined that the gusset plates failed in the heat-affected zone via an intergranular microcracking mode due to hydrogen-assisted underbead and toe-weld cracking. Proper nondestructive testing techniques for magnetic particle and radiographic inspection of the plate-weld gusset areas were...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001105
EISBN: 978-1-62708-214-3
..., respectively. Visual examination of the bellows revealed cracks in heavily cold-worked areas (both inside and outside) and considerable corrosion. SEM analysis showed a classical intergranular failure pattern with microcracking. The threaded tie rod microstructure contained spheroidized carbide that was more...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001000
EISBN: 978-1-62708-229-7
..., microcracks, and aligned damage centers which showed up as voids upon repeated polish-etch cycles. Because of the local nature of creep damage that can occur, any inspection that involves in situ metallography must be conducted at exactly the right or critical position or the presence of damage may not be...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001193
EISBN: 978-1-62708-229-7
... partially as fatigue cracks produced by vibration in the operation of the turbine as a result of steplike growing of microcracks could not be deduced from the fracture surfaces. Microfractography showed that the cracks developed in stages. Brazing Residual stress Steam turbines X20Cr 13 Joining...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001735
EISBN: 978-1-62708-220-4
... principal tensile stress and of microcracks resulting from their linkage. These features are revealed by repeated polishing and etching techniques, described elsewhere ( 1 ). The damage is mainly concentrated within the inner one third of the wall thickness. Damage may be classified as of levels A to D...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001110
EISBN: 978-1-62708-214-3
... larger and coarser than the longitudinal crack, in agreement with the SEM fractographic results. Fig. 7 Optical micrograph from a longitudinal section in the plane of the tube wall, showing a transverse microcrack filled with oxide. As polished. 315×. Fig. 8 Optical micrograph from a...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001779
EISBN: 978-1-62708-241-9
... surface Fig. 9 The effects of microcracks and deformation in an area Signs of cavitation damage were found in the damaged part by more examination with SEM as shown in Fig. 8 . These signs prove that the energy of bubble cracking was used to produce work-hardening and then make the...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001736
EISBN: 978-1-62708-220-4
... stress creep damage showing up as damage centers or voids, and the microstructural damage observed was in the form of grain boundary sliding and resulting microcracks, ahead of and adjacent to the main cracks. Figure 2 shows a representative view of the pipe material outside of the heat affected zone...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001004
EISBN: 978-1-62708-229-7
... RTE fracture, initiation and propagation of microcracks are rate controlling while at high temperatures the nucleation and growth of creep cavitation, dislocation mobility and grain boundary sliding are important. Wilkinson et al ( 6 ) observed that the ductility of P-doped 1 1 4 Cr1Mo...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001114
EISBN: 978-1-62708-214-3
... general yielding. Initiation of the brittle fracture was traced to a zone containing microcracks and composed of a hard martensitic constituent produced by rapid cooling after welding. The microcracks in the HAZ were produced by thermal shrinkage strains acting on a weld HAZ that had been embrittled by an...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001049
EISBN: 978-1-62708-214-3
...-magnification view of this area and reveals microcracks adjacent to the carbide particles. Figure 7 , taken from a polished specimen, shows corrosion product filling a crack. Fig. 5 SEM micrograph showing aligned dendrites and associated niobium carbide particles. Note crack following interdendritic path...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001820
EISBN: 978-1-62708-241-9
... A216 steel ( a ) main crack, ( b ) branched cracks. Cracks extended from inner surface to the base metal In addition to the main SSC crack at the metal surface, nucleation of microcracks inside the metal was observed ( Fig. 5b ). Crack propagation likely occurred by bursts in which the most...