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Medium-frequency induction hardening for rear axle casing
Int. J. Fatigue Vat. 18, No. 4, pp. 273-276, 1996 Copyright © 1996 Published by Elsevier Science Limited Printed in Great Britain. All rights reserved 0142-1123/96/$15.00
ELSEVIER
0142-1123(95)00067-4
Fatigue Abstracts This section contains abstracts of selected articles, technical reports, dissertations and patents concerned with fatigue. It is prepared in collaboration with Materials Information, a joint service of The Institute of Materials and ASM International. Readers wishing to obtain the full text of articles abstracted here should contact either: The Institute of Materials, 1 Carlton House Terrace, London S W l Y 5DB, UK, or: ASM International, Metals Park, OH 44073, USA (not International Journal of Fatigue). The fees charged for photocopying articles are £7.00 for the first ten pages and £3.00 per additional ten pages (UK office), or $10.00 for the first ten pages and $4.00 per additional ten pages (US office).
Fatigue crack propagation resistance of AI203 particulate reinforced aluminum alloys. Leroy, P., Charrier, J. and Petit, J. Proc. Conf. Recent Developments in Light Metals, Toronto, Ontario, Canada 20-23 Aug. 1994 87-96
A direct comparison between the fatigue crack propagation properties of the reinforced and unreinforced materials is possible, because alloy 8009 requires no postprocessing heat treatment. As a consequence, this comparison reflects the influence of the SiC particulate and not differences in microstructure that could arise during processing and ageing. The experimental data demonstrate that the SiC-reinforced material exhibits modestly superior fatigue crack propagation properties: slower crack growth propagation rates for a given AK, at near-threshold crack growth rates. Even when the data are corrected for crack closure using an effective stress intensity factor AKefr, the composite exhibits lower crack propagation rates than the unreinforced matrix alloy. Microscopic evidence shows a rougher fracture surface and a more tortuous crack path in the composite than in the base alloy. It is argued that the lower crack growth rates and higher intrinsic threshold stress intensity factor observed in the composite are associated with crack deflection around SiC particles. Graphs, photomicrographs, 34 ref.
This paper deals with a study of fatigue crack propagation (FCP) resistance of two industrial MMC:2014/15% wt.-AI203 particulates and 6061/20% wt.AI20 s particulates. First studied were the metallurgical structure and the AI203 particles; then the FCP resistance was characterized. The limited FCP resistance of both alloys is shown directly related to their limited toughness properties as observed previously on SiC-reinforced alloys. The observed steep da/dN vs AK propagation curves result from the combination of lower toughness and high threshold for MMC compared with unreinforced alloys. But after correction, the propagation of AI2Os-reinforeed MMC and conventional alloys can be rationalized in terms of effective stress intensity factor range. A1~O3 particulates do not seem to generate a bridging effect similar to that observed induced by SiC particulates or whiskers. This means that most of the differences in the nominal FCP might be found in the closure contribution. Fractographic observations support that the governing mechanisms for FCP in MMC as well as in conventional alloys mostly depend on the alloy of the matrix (composition and microstructure). Complementary tests performed in high vacuum have shown a detrimental influence of ambient air, which can also be directly related to the environmental sensitivity of the matrix. Graphs, photomicrographs, 6 ref.
Medium-frequency induction hardening for rear axle casing. Li, Q. Heat Treat. Met. (China) (May 1994) 201 (5); 44-45 (in Chinese) The CAI41 rear axle casing of 45Mn2 seamless tube requires surface hardness at 52-57HRC, quenching thickness at 2-4 mm, high fatigue strength, and high surface abrasion resistance. Medium-frequency induction hardening can ensure that the CA141 rear axle casing has its required mechanical properties. The technique of medium-frequency induction for hardening the CA141 rear axle casing is described. The technological parameters of medium-frequency induction hardening are discussed.
Fatigue crack propgation of extruded 19 vol.% SiCw/6061 AI composites under (1 + II) mixed loading. Wang, D., Ye, F., Yao, Z., Liu, J., Wang, Z. and Uy, W. Chin. J. Mater. Res. (June 1994) 8 (3), 283-288 (in Chinese) The fatigue crack propagation threshold and the crack deflection angle under ( I + I I ) mixed-mode loading were studied in a hot-extruding 19 vol.%SiCw/6061 AI composite. The microstructure and fractography of the composites were observed by SEM. The fatigue crack propagation mechanism and the crack deflection behaviour were discussed. The results show that both AK~ and Akt~q decreased with Ak~ increasing, indicating that the fatigue propagation threshold for the (I + II) mixed-mode loading is controlled not only by the mode I component but also by the mode U component. With Ak, increasing, the fatigue crack propagation direction of both L-T and T - L specimens of SiCw/LD2 composites under mixed mode (I + II) loading are perpendicular to the maximum normal stress at the crack tip. A critical Akr Ak~h bound curve, which was divided into a non-propagation region and a propagation region, was also obtained for the threshold condition. When both Akr and Ak~ attain the critical bound curve in common, the mixed ( I + i l ) cracks begin to propagate. The crack propagation resistance varies with the crack deflection angle. Graphs, photomicrographs, 7 ref.
Metallographic analysis of laser-hardened tooth face of gear. Ma, X. and la'u, J. Heat Treat. Met. (China) (1994) 8 14-17 (in Chinese) The laser hardening of the tooth face of a gear made of 30CrMnTi steel by a 2 kW continuous CO 2 laser is introduced. The structures and microhardness of the laser-hardened tooth face are analysed and compared with those of an induction-hardened tooth face. The laser-hardened structure is acicular martensite. The laser-hardened tooth face has high hardness and high contact fatigue strength. Graphs, photomicrographs, 5 ref.
Influence of conditioning on microstructure and W6MoSCr4V2 high speed steel. Fang, Q., Ma, X. and Long, J. Heat Treat. Met. (China) (1994) 7 7-10 (in Chinese)
The influence of SiC particulates on fatigue crack propagation in a rapidly solidified AI-Fe-V-Si alloy. Sutherland, TJ., Hoffman, P.B. and Gibeling, J.C. Metall. Mater. Trans. A (Nov. 1994) 25A (11), 2453-2460
properties
of
The influence of conditioning on the microstructure and properties of W6MotCr4V2 high-speed steel is discussed. The results show that, compared with annealing as conditioning treatment, the microstructure after conditioning with quenching and tempering has finer austenite grains, fewer undissolved carbides, and more retained austenite. Because of this, it shows higher yield strength and longer fatigue life in the low-stress region, but the bending strength, ductility, impact toughness and fracture toughness are lower, and the fatigue life in the high-stress region is shorter too. Graphs, photomicrographs, 3 ref.
The fatigue crack propagation properties of a rapidly solidified aluminium alloy are compared with those of a metal matrix composite (MMC) made of the same base alloys with the addition of 11.5 vol.% SiC particulate. The high-temperature base material, alloy 8009 produced by Allied-Signal, Inc. (Morristown, NJ), is solidified and processed using powder metallurgy techniques; these techniques yield a fine-grained, non-equilibrium microstructure.
273
ELSEVIER
0142-1123(95)00067-4
Fatigue Abstracts This section contains abstracts of selected articles, technical reports, dissertations and patents concerned with fatigue. It is prepared in collaboration with Materials Information, a joint service of The Institute of Materials and ASM International. Readers wishing to obtain the full text of articles abstracted here should contact either: The Institute of Materials, 1 Carlton House Terrace, London S W l Y 5DB, UK, or: ASM International, Metals Park, OH 44073, USA (not International Journal of Fatigue). The fees charged for photocopying articles are £7.00 for the first ten pages and £3.00 per additional ten pages (UK office), or $10.00 for the first ten pages and $4.00 per additional ten pages (US office).
Fatigue crack propagation resistance of AI203 particulate reinforced aluminum alloys. Leroy, P., Charrier, J. and Petit, J. Proc. Conf. Recent Developments in Light Metals, Toronto, Ontario, Canada 20-23 Aug. 1994 87-96
A direct comparison between the fatigue crack propagation properties of the reinforced and unreinforced materials is possible, because alloy 8009 requires no postprocessing heat treatment. As a consequence, this comparison reflects the influence of the SiC particulate and not differences in microstructure that could arise during processing and ageing. The experimental data demonstrate that the SiC-reinforced material exhibits modestly superior fatigue crack propagation properties: slower crack growth propagation rates for a given AK, at near-threshold crack growth rates. Even when the data are corrected for crack closure using an effective stress intensity factor AKefr, the composite exhibits lower crack propagation rates than the unreinforced matrix alloy. Microscopic evidence shows a rougher fracture surface and a more tortuous crack path in the composite than in the base alloy. It is argued that the lower crack growth rates and higher intrinsic threshold stress intensity factor observed in the composite are associated with crack deflection around SiC particles. Graphs, photomicrographs, 34 ref.
This paper deals with a study of fatigue crack propagation (FCP) resistance of two industrial MMC:2014/15% wt.-AI203 particulates and 6061/20% wt.AI20 s particulates. First studied were the metallurgical structure and the AI203 particles; then the FCP resistance was characterized. The limited FCP resistance of both alloys is shown directly related to their limited toughness properties as observed previously on SiC-reinforced alloys. The observed steep da/dN vs AK propagation curves result from the combination of lower toughness and high threshold for MMC compared with unreinforced alloys. But after correction, the propagation of AI2Os-reinforeed MMC and conventional alloys can be rationalized in terms of effective stress intensity factor range. A1~O3 particulates do not seem to generate a bridging effect similar to that observed induced by SiC particulates or whiskers. This means that most of the differences in the nominal FCP might be found in the closure contribution. Fractographic observations support that the governing mechanisms for FCP in MMC as well as in conventional alloys mostly depend on the alloy of the matrix (composition and microstructure). Complementary tests performed in high vacuum have shown a detrimental influence of ambient air, which can also be directly related to the environmental sensitivity of the matrix. Graphs, photomicrographs, 6 ref.
Medium-frequency induction hardening for rear axle casing. Li, Q. Heat Treat. Met. (China) (May 1994) 201 (5); 44-45 (in Chinese) The CAI41 rear axle casing of 45Mn2 seamless tube requires surface hardness at 52-57HRC, quenching thickness at 2-4 mm, high fatigue strength, and high surface abrasion resistance. Medium-frequency induction hardening can ensure that the CA141 rear axle casing has its required mechanical properties. The technique of medium-frequency induction for hardening the CA141 rear axle casing is described. The technological parameters of medium-frequency induction hardening are discussed.
Fatigue crack propgation of extruded 19 vol.% SiCw/6061 AI composites under (1 + II) mixed loading. Wang, D., Ye, F., Yao, Z., Liu, J., Wang, Z. and Uy, W. Chin. J. Mater. Res. (June 1994) 8 (3), 283-288 (in Chinese) The fatigue crack propagation threshold and the crack deflection angle under ( I + I I ) mixed-mode loading were studied in a hot-extruding 19 vol.%SiCw/6061 AI composite. The microstructure and fractography of the composites were observed by SEM. The fatigue crack propagation mechanism and the crack deflection behaviour were discussed. The results show that both AK~ and Akt~q decreased with Ak~ increasing, indicating that the fatigue propagation threshold for the (I + II) mixed-mode loading is controlled not only by the mode I component but also by the mode U component. With Ak, increasing, the fatigue crack propagation direction of both L-T and T - L specimens of SiCw/LD2 composites under mixed mode (I + II) loading are perpendicular to the maximum normal stress at the crack tip. A critical Akr Ak~h bound curve, which was divided into a non-propagation region and a propagation region, was also obtained for the threshold condition. When both Akr and Ak~ attain the critical bound curve in common, the mixed ( I + i l ) cracks begin to propagate. The crack propagation resistance varies with the crack deflection angle. Graphs, photomicrographs, 7 ref.
Metallographic analysis of laser-hardened tooth face of gear. Ma, X. and la'u, J. Heat Treat. Met. (China) (1994) 8 14-17 (in Chinese) The laser hardening of the tooth face of a gear made of 30CrMnTi steel by a 2 kW continuous CO 2 laser is introduced. The structures and microhardness of the laser-hardened tooth face are analysed and compared with those of an induction-hardened tooth face. The laser-hardened structure is acicular martensite. The laser-hardened tooth face has high hardness and high contact fatigue strength. Graphs, photomicrographs, 5 ref.
Influence of conditioning on microstructure and W6MoSCr4V2 high speed steel. Fang, Q., Ma, X. and Long, J. Heat Treat. Met. (China) (1994) 7 7-10 (in Chinese)
The influence of SiC particulates on fatigue crack propagation in a rapidly solidified AI-Fe-V-Si alloy. Sutherland, TJ., Hoffman, P.B. and Gibeling, J.C. Metall. Mater. Trans. A (Nov. 1994) 25A (11), 2453-2460
properties
of
The influence of conditioning on the microstructure and properties of W6MotCr4V2 high-speed steel is discussed. The results show that, compared with annealing as conditioning treatment, the microstructure after conditioning with quenching and tempering has finer austenite grains, fewer undissolved carbides, and more retained austenite. Because of this, it shows higher yield strength and longer fatigue life in the low-stress region, but the bending strength, ductility, impact toughness and fracture toughness are lower, and the fatigue life in the high-stress region is shorter too. Graphs, photomicrographs, 3 ref.
The fatigue crack propagation properties of a rapidly solidified aluminium alloy are compared with those of a metal matrix composite (MMC) made of the same base alloys with the addition of 11.5 vol.% SiC particulate. The high-temperature base material, alloy 8009 produced by Allied-Signal, Inc. (Morristown, NJ), is solidified and processed using powder metallurgy techniques; these techniques yield a fine-grained, non-equilibrium microstructure.
273