Hot rolled steel sheets and method of producing the same
US5853503A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1997 |
| Grant date | Dec 29, 1998 |
| Priority date | — |
| Expiry date | Apr 28, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21B1/26
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
After a starting material of steel comprising C: 0.001-0.20 wt %, Si: 0.01-0.50 wt %, Mn: 0.05-2.0 wt %, P: not more than 0.05 wt %, S: not more than 0.05 wt %, sol.Al: 0.01-0.10 wt %, N: not more than 0.020 wt % and the balance being Fe and inevitable impurities is heated above AC.sub.3 point, rough rolling is completed within a temperature range of (Ar.sub.3 point+100.degree. C.)-(Ar.sub.3 point+50.degree. C.), and super-high pressure descaling is carried out under conditions satisfying a jetting pressure of not less than 25 kgf/cm.sup.2 and a liquid quantity density of not less than 0.002 liter/cm.sup.2, and subsequently finish rolling at a rolling reduction of not less than 80% above Ar.sub.3 point of a rolling completion temperature is started in 5 seconds and coiling is carried out below 700.degree. C., whereby hot rolled steel sheets having a surface roughness Ra of not more than 0.8 .mu.m and an average scale thickness of not more than 4 .mu.m is produced and the adhesion property in case of subjecting to shaping at a mill scale state and the pickling efficiency in case of applying to pickling are improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.