Case hardening steel, method of producing case hardening steel, and method of producing gear part
US11174543B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2017 |
| Grant date | Nov 16, 2021 |
| Priority date | — |
| Expiry date | Aug 28, 2037 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H55/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A case hardening steel suitable as raw material for producing a mechanical structural part having high rotating bending fatigue strength and pitting fatigue strength at relatively low cost and a method of producing the case hardening steel are provided. A case hardening steel comprises a chemical composition containing, in mass %, C, Si, Mn, P, S, Cr, Mo, Al, N, and O in a predetermined relationship, with a balance being Fe and inevitable impurities, wherein √I≤80 (where I denotes an area (μm2) of an oxide-based inclusion located in a fish eye central portion at a fracture surface after subjecting the case hardening steel to carburizing-quenching and tempering and then performing a rotating bending fatigue test).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.