Retarded aging, rimmed steel with good surface quality
US4375376A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1981 |
| Grant date | Mar 1, 1983 |
| Priority date | — |
| Expiry date | Dec 9, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/902
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A rimmed steel product, in as-hot-rolled, or cold rolled and annealed form, is made essentially non-aging by inclusion of one or both of the aging-retardant elements vanadium and boron, while retaining an excellent, clear surface that is not adversely affected by the presence of such element or elements. To produce such articles, an ingot mold is poured 80 to 95% full of plain rimming steel, and the molten steel is allowed to rim, e.g. for several minutes, until a rimmed shell solidifies against the mold wall. Then pouring is completed with the same steel, while adding one or both of the aging-retardant elements to the teemed stream. Processed like rimmed steel, ultimate rolled (e.g. strip) products having a thin, truly rimmed skin over a main body of substantially non-aging steel, are found to exhibit no unwanted change of properties (e.g. as would be revealed by significant strain lines) such as usually characterizes the effect of aging in rimmed steel. There is some advantage in using the two elements together, or in the simultaneous inclusion of other, strength-promoting elements such as Cb, Zr, Si, and it has been noted that tensile properties are enhanced when V is added, as …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.