Salem Ben Mohamed - Academia.edu (original) (raw)
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Papers by Salem Ben Mohamed
International Journal of Materials Science and Applications
Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in servi... more Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in service under specific cyclic stress conditions of the operating mode of its bodies. The treatment of ion nitriding during 20 hours with 520°C applied to 42CrMo4 steel in an untreated state (quenched and tempered) led to the formation of a compound layer (mixture of nitrides γ' and carbonitrides ε with irregular thickness evaluated at 5µm and a diffusion layer of depth equal to 295µm). In the diffusion layer, the presence of inserted nitrogen leads to the increase in hardness (3 times that of basic material) and to the creation of a compressive residual stress field (-400MPa). This superficial hardening does not modify the tensile mechanical characteristics of 42CrMo4 steel but renders it more sensitive to overload in fatigue. As a result, a 0.7% total deformation imposed corresponding to a loading level of 850MPa, constitutes the limit of gain in fatigue obtained by the ion nitriding considered.
Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in servi... more Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in service under specific cyclic stress conditions of the operating mode of its bodies. The treatment of ion nitriding during 20 hours with 520°C applied to 42CrMo4 steel in an untreated state (quenched and tempered) led to the formation of a compound layer (mixture of nitrides g' and carbonitrides e with irregular thickness evaluated at 5µm and a diffusion layer of depth equal to 295µm). In the diffusion layer, the presence of inserted nitrogen leads to the increase in hardness (3 times that of basic material) and to the creation of a compressive residual stress field (-400MPa). This superficial hardening does not modify the tensile mechanical characteristics of 42CrMo4 steel but renders it more sensitive to overload in fatigue. As a result, a 0.7% total deformation imposed corresponding to a loading level of 850MPa, constitutes the limit of gain in fatigue obtained by the ion nitriding considered.
International Journal of Materials Science and Applications
Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in servi... more Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in service under specific cyclic stress conditions of the operating mode of its bodies. The treatment of ion nitriding during 20 hours with 520°C applied to 42CrMo4 steel in an untreated state (quenched and tempered) led to the formation of a compound layer (mixture of nitrides γ' and carbonitrides ε with irregular thickness evaluated at 5µm and a diffusion layer of depth equal to 295µm). In the diffusion layer, the presence of inserted nitrogen leads to the increase in hardness (3 times that of basic material) and to the creation of a compressive residual stress field (-400MPa). This superficial hardening does not modify the tensile mechanical characteristics of 42CrMo4 steel but renders it more sensitive to overload in fatigue. As a result, a 0.7% total deformation imposed corresponding to a loading level of 850MPa, constitutes the limit of gain in fatigue obtained by the ion nitriding considered.
Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in servi... more Steel 42CrMo4, used in the manufacturing of transmission systems (gears), poses problems in service under specific cyclic stress conditions of the operating mode of its bodies. The treatment of ion nitriding during 20 hours with 520°C applied to 42CrMo4 steel in an untreated state (quenched and tempered) led to the formation of a compound layer (mixture of nitrides g' and carbonitrides e with irregular thickness evaluated at 5µm and a diffusion layer of depth equal to 295µm). In the diffusion layer, the presence of inserted nitrogen leads to the increase in hardness (3 times that of basic material) and to the creation of a compressive residual stress field (-400MPa). This superficial hardening does not modify the tensile mechanical characteristics of 42CrMo4 steel but renders it more sensitive to overload in fatigue. As a result, a 0.7% total deformation imposed corresponding to a loading level of 850MPa, constitutes the limit of gain in fatigue obtained by the ion nitriding considered.