Crankshaft and method of manufacturing the same
AssigneeNippon Steel Corporation
InventorsTatsuhiko Abe, Satoru Okawa, Masato Yuya
Life of this patent
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Abstract
A crankshaft with improved seizure resistance is provided. A crankshaft having journals 11 and pins 12 includes a compound layer containing iron and nitrogen on its surface, wherein, in the compound layer, for both the journals 11 and pins 12, the porosity area ratio of the thinner one of a region from the surface to a depth of 3.0 μm and a region across the total thickness of the compound layer is not higher than 10.0%, and both the journals 11 and pins 12 have such a surface geometry that the arithmetical mean deviation of the primary profile, Pa, is not larger than 0.090 μm.
Claims6
A crankshaft having a journal and a pin, including a compound layer containing iron and nitrogen on a surface thereof,
- wherein, in the compound layer, for each of the journal and pin, a porosity area ratio of a thinner one of a region from the surface to a depth of 3.0 μm and a region across a total thickness of the compound layer is not higher than 10.0%, and
- each of the journal and pin has such a surface geometry that an arithmetical mean deviation of a primary profile, Pa, is not larger than 0.090 μm.
Dependencies are inferred from the claim text.