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Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001834
EISBN: 978-1-62708-241-9
... observed on the inner wall showed obvious vapor oxidation corrosion characteristics. Corrosion originated in the grain boundary, and selective oxidation occurred due to ion diffusion in the substrate. The layered oxide scale on the inner wall is related to the different diffusion rates for different...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001816
EISBN: 978-1-62708-241-9
... A material is considered to have superplastic behavior when it shows extremely high and uniform elongations (from 100 to 1000%) under tension stress: a lack of localized necking or a series of diffuse necks along the test zone resulting from a combination of the creep tension stress and the strain rate...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001829
EISBN: 978-1-62708-241-9
... can be as high as 150 °C and is sometimes quoted as being up to 190 °C [ 7 ]. Temperature increases caused by spallation of top coat can increase diffusion rate. In the welded region ( Fig. 4c ), the composition of cobalt and nickel at the substrate are more analogous to bond coat. Compared...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.mech.c0048634
EISBN: 978-1-62708-225-9
... diffusion of mobile hydrogen outward from the surface of the pin. After the cadmium layer was removed, the mobile hydrogen contained on the surface of the steel and in the electroplated deposit was released, and the embrittlement problem was alleviated. To prevent reoccurrence, the bright cadmium layer...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001304
EISBN: 978-1-62708-215-0
...Abstract Abstract An exhaust diffuser assembly failed prematurely in service. The failure occurred near the intake end of the assembly and involved fracture in the diffuser cone (Corten), diffuser in take flange (type 310 stainless steel), diffuser exit flange (type 405 stainless steel...
Image
Published: 01 January 2002
Fig. 2 Wear-mechanism map for unlubricated sliding of a steel couple. The normalized pressure is the contact pressure divided by hardness. The normalized velocity is the velocity multiplied by the ratio of the radius of the contact to the thermal diffusivity. The contour lines are lines More
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001174
EISBN: 978-1-62708-220-4
... and the transverse borings. Under both borings the structure appeared to have been loosened by intergranular separations ( Figs. 6 , 7 , 8 ). These are the significant characteristics of hydrogen attack 1 . Decarburization had not yet become perceptible because of the small diffusion rate of carbon at the low...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.process.c9001447
EISBN: 978-1-62708-235-8
... present as an impurity in the carbon monoxide. 8 The diffusion rate of hydrogen is more than 105 times greater than that of carbon monoxide at the same temperatures. 8 Fig. 7 Influence of hydrogen and temperature on incubation for heating periods of 1 1 2 hours. In some...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001738
EISBN: 978-1-62708-220-4
... creep are taken from manufacturers (Inco, Sandvik) and from free literature. These data are put into a Larson-Miller equation by regression analysis. Data for diffusional creep are taken from 6 . The creep rate in service is 2.1% in 13 years which equals 5.1 · 10 −11 1/s or 1.8 · 1- −7 1/hr...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.petrol.c0048830
EISBN: 978-1-62708-228-0
..., and held for 2 1 4 h. The vessel was then cooled at a rate prescribed by the ASME code. This treatment caused hydrogen to be diffused out of the metal, thus removing the source of embrittlement. The weld metal on both sides of the crack and 5 mm ( 3 16 in.) of base metal...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006816
EISBN: 978-1-62708-329-4
... microstructure the Ac 3 increases with heating rate, a consequence of the shorter processing times at the higher heating rates, and the corresponding need to heat the samples to higher temperatures to achieve the same extent of diffusion-controlled microstructural changes that would develop for longer times...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.bldgs.c9001702
EISBN: 978-1-62708-219-8
... permeable void fraction was 50 pct higher than that of the original concrete. The patch concrete was more permeable to mass transfer of fluids than the original concrete. Chloride diffusion rates were higher in the patch concrete than the original concrete. There were some differences between the aggregate...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001616
EISBN: 978-1-62708-229-7
... in Stage 3 was more (log mean temperature = 122 °C) than in Stage 2, where the log mean temperature was only 108 °C. This high heat transfer rate in Stage 3 would have resulted in condensation of some flue gas constituents on the ID of the tube. These condensed phases later diffused into the base metal due...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003555
EISBN: 978-1-62708-180-1
... and reacts with the carbides to form methane, 4H + Fe 3 C ⇒ CH 4 + 3Fe, and internal microcracks that lead to brittle rupture. The reaction rate is dependent on hydrogen concentration, diffusion, and total gaseous pressure and occurs at 200 to 600 °C (390 to 1110 °F). Hydrogen damage has been observed...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.marine.c9001003
EISBN: 978-1-62708-227-3
... to the rates experienced in the present failures. The diffusivity of the hydrogen is certainly adequate to move it throughout the steel; but at ambient temperature the carbon cannot move to the inclusion, high-angle grain boundaries, or whatever special site is required to permit reaction with the hydrogen...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006781
EISBN: 978-1-62708-295-2
... of creep may manifest as grain-boundary movement or sliding, dislocation glide, dislocation glide plus climb, and/or the diffusion of chemical species within the lattice. The rate equation that governs most forms of crystalline creep may be simplified to the following functional form ( Ref 2 ): (Eq 2...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001133
EISBN: 978-1-62708-214-3
... (2600 °F) for a 0.30% C alloy to up to 1495 °C (2720 °F) for pure cobalt. Because the rate of diffusion and consequently the rate of diffusion bonding are functions of homologous temperature ( T/T melting ), the lower-carbon surface layer can be expected to inhibit diffusion and significantly reduce...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001322
EISBN: 978-1-62708-215-0
... Boiler operating conditions Table 1 Boiler operating conditions Boiler rating (maximum continuous) 200 Mg/h (180 ton/h) Average operating load 130 Mg/h (120 ton/h) Average operating pressure 6.2 MPa (900 psig) Internal temperature of main bank tubes 275 °C (527 °F) Tube material...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001107
EISBN: 978-1-62708-214-3
... the carbides depicted in Fig. 3 . 3150×. The microstructure near the liner OD displayed faint characteristics of the austenitic structure, indicating that carbon had diffused from the ID into the liner. Areas that were relatively unaffected had a composite grain structure ( Fig. 5 ). Varying bandwidths...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001827
EISBN: 978-1-62708-241-9
... corrosion. Therefore, surface protection is required to minimize this effect. To protect and delay the destructive hot corrosion action, special corrosion protective coatings of two types, aluminide or chromium (diffusion) coatings and overlay coatings, are applied. Also to reduce the exposure...