Tool for piercing mill
US9194031B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2012 |
| Grant date | Nov 24, 2015 |
| Priority date | — |
| Expiry date | Dec 9, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24967
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A tool for a piercing mill, the tool comprising a scale layer in a surface layer of a substrate steel, wherein the scale layer includes a net structure scale layer that is formed on a substrate steel side, has a thickness of 10 to 200 μm in a depth direction, and is complicatedly intertwined with a metal; and wherein a microstructure on the substrate steel side in a range of at least 300 μm in the depth direction from an interface between the net structure scale layer and the substrate steel contains a ferrite phase at an area fraction of 50% or more, the ferrite phase containing 400/mm2 or more ferrite grains having a maximum length of 1 to 60 μm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.