Production process for producing hollow steel tube of high strength
US5405459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Oct 18, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2261/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A production process for producing a hollow steel tube of a high strength includes the steps of a tube preparation step of producing a seamless steel tube of a heavy thickness containing flaws of less than 0.25 mm in depth in an inner periphery thereof, a tube inner periphery correction step of correcting at least the flaws having a width of 0.001 mm or less so as to have a depth of 0.15 mm or less, and a hardening step of hardening the seamless steel tube across a whole thickness thereof to a hardness of from 450 to 670 in Vickers hardness (Hv). The production process enables not only to produce a hollow steel tube of a high strength at a less production cost but also to adapt it to exhibit such a high torsional fatigue fracture resistance and a high impact strength that it is applicable to axles for large size automobiles producing high outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.