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Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001687
EISBN: 978-1-62708-220-4
... properties. Grain boundary sliding and dislocation motion were enhanced, causing a local increase in the steady state strain rate and the premature failure of the tube. Grain boundary sliding Plastic deformation Spalling Voids HK UNS J94224 Creep fracture/stress rupture The petrochemical...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.modes.c0060144
EISBN: 978-1-62708-234-1
... filled with a nickel catalyst. The tubes were centrifugally cast from ASTM A297, grade HK-40 (Fe-25Cr-20Ni-0.40C), heat-resistant alloy. The tube was concluded after metallurgical inspection to have failed from creep rupture (i.e., stress rupture). A project for detecting midwall creep fissuring was...
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
... Abstract A sample tube was removed from a reformer furnace for life assessment after 69,000 h of service. Sections were cut from the tube, which was a spindle cast A297 Grade HK 40 (25 Cr, 20 Ni, 0.4 C) austenitic steel of 122.5 mm OD and 10.5 mm nominal wall thickness. They were examined...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001280
EISBN: 978-1-62708-215-0
... Abstract An HK-40 alloy tubing weld in a reformer furnace of a petrochemical plant failed by leaking after a shorter time than that predicted by design specifications. Leaking occurred because of cracks that passed through the thickness of the weldment. Analysis of the cracked tubing indicated...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.steel.c9001714
EISBN: 978-1-62708-232-7
... Abstract In a HyL III heat exchanger's radiant pipes, metal dusting reduced the pipe thickness from 8.5 to 3 mm in just nine months, leaving craters on the inner surface. The pipes are fabricated from HK 40 alloy. The heated gas (400 to 800 deg C) consisted of CO, CO2, and H2, with a 4:1 CO/CO2...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001051
EISBN: 978-1-62708-214-3
... microhardness measurements was performed. The base material, heat-affected zone (HM), and weld metal had average Knoop readings of 207, 271, and 270 HK respectively (where 207 HK ≅ 8.7 HRC and 274 HK ≅ 24 HRC), values consistent with an ASTM A302 grade B material. The epoxy mold for sample B was broken open...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.usage.c0046366
EISBN: 978-1-62708-236-5
... one of the deep score marks in the aluminum alloy adapter revealed a large particle of chromium embedded in the groove ( Fig. 1c ). A hardness test performed on the particle indicated a hardness of 850 HK (66 HRC); the hardness of the aluminum alloy adjacent to the particle was 186 HK (86 HRB). It...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001381
EISBN: 978-1-62708-215-0
... HK (∼41 HRC). Transverse specimens had an average hardness of 441 HK (∼45 HRC). ...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.modes.c0048846
EISBN: 978-1-62708-234-1
... suggest that the ferrite bands served as initiation sites for the failure and that they lowered the rupture strength of the weld metal. The Knoop hardnesses of the bands tended to be in the range 138 to 144 HK, while the adjacent areas of the interbead HAZ were 161 to 168 HK. Qualitative analyses of the...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c0048777
EISBN: 978-1-62708-229-7
... microhardness of the dendritic layer was 489 to 591 HK and 47 to 52 HRC, while the HAZ was 179 to 258 HK and 85 HRB to 21 HRC. A qualitative microprobe analysis of the dendritic layer revealed that it contained over 1% C, higher than the carbon content of the base metal. This high hardness is consistent with...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001065
EISBN: 978-1-62708-214-3
... established merely to verify that a metal electrode is composed of carbon steel. Knoop (microhardness) hardness measurements were performed on the cross section of one of the sections removed. Average hardness values (500 gf load) were as follows: pipe, 159 HK; HAZ (pipe side), 176 HK; weld, 197 HK; HAZ...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001267
EISBN: 978-1-62708-215-0
... measurements were obtained on the longitudinally cross-sectioned wires ( Table 1 ). The longitudinal indentations were obtained in the center of the wire, indicating an average Knoop hardness of 617 HK, which corresponds to 54 HRC—well below the properties specified for 0.76 mm (0.030 in.) wire ( Fig. 9...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.modes.c9001671
EISBN: 978-1-62708-234-1
... a much harder epsilon-carbide structure with a relative hardness of 790 HK (25gf load). This sub-layer has an apparent unresolved substructure after etching. A second layer, which is occasionally reported, is a lower carbon containing austenitic layer with a hardness of 403 HK which lacks any...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.mech.c0090994
EISBN: 978-1-62708-225-9
... peened. The microhardness of the wire averaged 591 Knoop (HK 500 ). This equates to an approximate ultimate tensile strength slightly higher than the specified range. The springs failed during installation due to the presence of preexisting defects. The crack surfaces were corroded and phosphate...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001043
EISBN: 978-1-62708-214-3
... was used for these tests. The results of the survey are as follows: Hardness HK HRC Dark Scale 741 60.8 503 47.5 548 50.4 Core material 684 57.7 712 59.0 These values confirm those obtained with the Rockwell tester on the surface of the material...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001329
EISBN: 978-1-62708-215-0
..., and 1 ppm total of other halogens. Microhardness (Knoop) testing (200 g load) yielded the following average values for the elbow and two valve bodies, respectively: 135, 148, and 163 HK (casting material); 85, 79, and 59 HK (dealloyed areas). Obviously, the microhardness values in the dealloyed...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001030
EISBN: 978-1-62708-214-3
... in.) diam hole having no interference-fit application and no cracks. The black diamonds in Fig. 8 show the microhardness indentations. The unaffected base metal hardness was an acceptable 493 HK (48 HRC). The brittle martensite layer was 852 HK (66 HRC). Analysis of a typical interference-fit...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001823
EISBN: 978-1-62708-241-9
... for results of the testing. The hardness in the white portion of Mount A (Region 1) was ~800 HK, which is consistent with the high hardness of eutectic iron. Region 1 must have been carburized from the coating or hydrocarbon product. The hardness in Region 2 (hardness locations B and C) ranged from...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001327
EISBN: 978-1-62708-215-0
... were performed on the base metal, weld, and HAZ of the large end of the reducer. Average values of 184, 211, and 199 HK, respectively, were obtained—typical for SA-106 grade B material. Tensile testing yielded the following results: yield strength, 367 MPa (53.2 ksi); ultimate tensile strength, 610...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.chem.c9001718
EISBN: 978-1-62708-220-4
.... The hardness of the two impellers was determined per ASTM E 384. The average measured hardness of the damaged and undamaged impellers is 186 and 209 HK 500g , respectively. These minor hardness differences do not account for the observed performance differences. ...