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Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.machtools.c9001574
EISBN: 978-1-62708-223-5
... Abstract A CrN coated restrike punch was made of WR-95 (similar to H-11), which was fluidized bed nitrided. The coated punch was used on hot Inconel at about 1040 deg C (1900 deg F). However, a water-soluble graphite coolant was used to maintain the punch temperature at 230 deg C (450 deg F...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001826
EISBN: 978-1-62708-241-9
... caustic attack that led to ruptures in areas of high stress. The escaping steam eroded the outer surface of the tube causing heavy loss of metal around the rupture points. boiler tubes stress rupture caustic corrosion carbon steel oxide scale deposits punch marks inductively coupled plasma...
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Published: 01 January 2002
Fig. 6 Punch made of AISI S7 tool steel that cracked during quenching. Temper color was observed on the crack walls. Cracking was promoted by and located by the very coarse machining marks. Magnetic particles have been used to emphasize the cracks. 0.5× More
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Published: 01 January 2002
Fig. 18 AISI O6 graphitic tool steel punch machined from centerless-ground bar stock that cracked after limited service. (a) Cracks (arrows) accentuated with magnetic particles. (b) Microstructural examination revealed an overaustenitized structure consisting of appreciable retained austenite More
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Published: 01 January 2002
Fig. 22 AISI S7 punch that had a low surface hardness after heat treatment and was given a second carburizing treatment, then rehardened. Cracking was observed after this retreatment (the cracks have been accentuated with magnetic particles). Coarse circumferential machining marks were present More
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Published: 01 January 2002
Fig. 23 Crack pattern on the bottom of the punch shown in Fig. 22 . Many of the cracks are located by the deep stamp marks (the cracks have been accentuated with magnetic particles). Actual size More
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Published: 01 January 2002
Fig. 24 Microstructure of the heavily carburized cracked punch shown in Fig. 22 and 23 . (a) Massive carbide enrichment at the surface. (b) Excess carbides at the base of the crack, about 0.7 mm (0.0275 in.) deep. (c) Structure at about 1.08-mm (0.0425-in.) depth. (d) Coarse More
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Published: 01 January 2002
Fig. 51 Failed AISI H26 exhaust-valve punch. (a) and (b) Longitudinal splitting of the punch caused by fatigue. Note the fracture progression starting from the top center at the punch. The punch surfaces were nitrided. (c) Top surface. 100× . (d) Extreme top surface. Note secondary crack More
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Published: 01 January 2002
Fig. 29 (a) The working face of an AISI L6 punch that failed after limited service, because (b) the punch was underaustenitized. Specimen etched with nital More
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Published: 01 December 1992
Fig. 2 Typical multiple cracks radiating from a punched hole in the reinforcing steel sheet (as-received). 3×. More
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Published: 30 August 2021
Fig. 6 Punch made of AISI S7 tool steel that cracked during quenching. Temper color was observed on the crack walls. Cracking was promoted by and located by the very coarse machining marks. Magnetic particles have been used to emphasize the cracks. Original magnification: 0.5× More
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Published: 30 August 2021
Fig. 18 AISI O6 graphitic tool steel punch machined from centerless-ground bar stock that cracked after limited service. (a) Cracks (arrows) accentuated with magnetic particles. (b) Microstructural examination revealed an overaustenitized structure consisting of appreciable retained austenite More
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Published: 30 August 2021
Fig. 22 AISI S7 punch that had a low surface hardness after heat treatment and was given a second carburizing treatment, then rehardened. Cracking was observed after this retreatment (the cracks have been accentuated with magnetic particles). Coarse circumferential machining marks were present More
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Published: 30 August 2021
Fig. 23 Crack pattern on the bottom of the punch shown in Fig. 22 . Many of the cracks are located by the deep stamp marks (the cracks have been accentuated with magnetic particles). Actual size More
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Published: 30 August 2021
Fig. 24 Microstructure of the heavily carburized cracked punch shown in Fig. 22 and 23 . (a) Massive carbide enrichment at the surface. (b) Excess carbides at the base of the crack, approximately 0.7 mm (0.0275 in.) deep. (c) Structure at approximately 1.08 mm (0.0425 in.) depth. (d) Coarse More
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Published: 30 August 2021
Fig. 51 Failed AISI H26 exhaust-valve punch. (a) and (b) Longitudinal splitting of the punch caused by fatigue. Note the fracture progression starting from the top center at the punch. The punch surfaces were nitrided. (c) Top surface. Original magnification: 100×. (d) Extreme top surface More
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Published: 01 December 1993
Fig. 3 Possible tearing mechanism during trimming. The punch pulls part of the material with it, causing stresses at the grain boundaries. Grains may separate and tear if the elastic limits reached. More
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Published: 15 January 2021
Fig. 38 (a) Working face of an AISI L6 punch that failed after limited service because (b) the punch was underaustenitized. Specimen etched with nital More
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Published: 01 June 2019
Fig. 12 Relationship between charpy FATT and Tsp (Small Punch Test Transition Energy). More
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Published: 15 May 2022
Fig. 23 Tear versus punched-hole fracture of acrylonitrile-butadiene-styrene at 8 km/h (5 miles/h), 25 °C (77 °F). Source: Ref 30 More