Depression-provided steel pipe and composite pile
US9062432B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2012 |
| Grant date | Jun 23, 2015 |
| Priority date | — |
| Expiry date | Feb 22, 2032 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D17/02
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
This depression-provided steel pipe has plural depressions on an outer peripheral surface, the depressions being formed so as to form a line along an axial direction of the steel pipe, in which each of the depressed portions has, inside thereof, a columnar groove portion extending along the axial direction of the steel pipe and depressed deeper than a bottom surface of these depressed portions; 0.95≦HA/HB≦1.05 is satisfied, where HA is an average Vickers hardness in each of the depressed portions, and HB is a Vickers hardness at a portion between the depressed portions adjacent to each other in the axial direction of the steel pipe; and the outer peripheral surface is covered with a mill scale.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.