The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 2002
Filed:
Jan. 24, 2000
Kawasaki Steel Corporation, , JP;
Abstract
High tensile strength hot-rolled steel sheet suitable for use in interior materials for automobiles and a method for producing the same, in which bake hardenability, fatigue resistance, crash resistance, and resistance to room temperature aging are improved, containing 0.01% to 0.12% by weight of carbon, 2.0% by weight or less of silicon, 0.01% to 3.0% by weight of manganese, 0.2% by weight or less of phosphorus, 0.001% to 0.1% by weight of aluminum, and 0.003% to 0.02% by weight of nitrogen and subjected to hot rolling and cooling at a cooling rate of 50° C./s or more within 0.5 second after hot rolling; the hot-rolled steel sheet has a structure including a ferrite having an average grain diameter of 8 &mgr;m or less as a primary phase, the amount of solute Nitrogen ranges from 0.003% to 0.01%, and the ratio, Ngb/Ng, of an average concentration Ngb of nitrogen dissolved in the ferrite grain boundary to an average concentration Ng of nitrogen dissolved in ferrite grains ranges from 100 to 10,000.