Quenched steel pipe member, vehicle axle beam using quenched steel pipe member, and method for manufacturing quenched steel pipe member
US9702019B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2013 |
| Grant date | Jul 11, 2017 |
| Priority date | — |
| Expiry date | Oct 10, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D9/0068
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A quenched steel pipe member is formed of a GI galvanized steel pipe, in a middle section in a longitudinal direction of the GI galvanized steel pipe, a cross-section perpendicular to the longitudinal direction has a substantially V shape including a contact section at which opposite parts of an inner circumferential surface of the GI galvanized steel pipe come into contact with each other, the contact section is bonded using a Fe—Zn alloy phase, and a micro Vickers hardness at a location 50 μm deep from a base material surface layer is 95% or more of a micro Vickers hardness at a location 200 μm deep from the base material surface layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.