Method of making wrought high tension steel having superior low temperature toughness
US4521258A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1983 |
| Grant date | Jun 4, 1985 |
| Priority date | — |
| Expiry date | Dec 16, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/005
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Due to increasing demands for steel to be used for construction such as buildings, pressure vessels, pipe lines or the like, various kinds of high tension steels, particularly steels suitable for welding have increasingly been developed. Heretofore, proposed methods of making such high tension steel have relied on so-called cold rolling and/or rolling followed by quenching and tempering, however, these conventional steels have suffered from drawbacks such as a tempering step indispensable after quenching, softening of welded zone and lack of uniformity in the metal structure in the direction of plate thickness. A compositional feature of the new method resides in addition of minor amounts of Ti and B along with Nb as contributing to grain refining or precipitation hardening elements in addition to limited amounts of other ingredients such as C, Si, Mn, S, Al and N. Further addition of at least one of V, Ni, Cu, Cr, Mo, Ca and REM also acts to improve the properties of the steel. The steel prepared to have the aforesaid composition is subjected to controlled heating, subsequent rolling under prescribed rolling reduction ratio, temperature for terminating rolling and to a specified c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.