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:
Aug. 28, 2018
Filed:
Aug. 07, 2014
Sanyo Special Steel Co., Ltd., Himeji-shi, JP;
Sanyo Special Steel Co., Ltd., Himeji-shi, JP;
Abstract
There is provided a steel, having an excellent rolling fatigue life, wherein an oxygen content in the steel is 8 ppm or less, a sulfur content is 0.008 mass % or less, and an Al content is 0.005 to 0.030 mass %, the number of non-metallic inclusions having an inclusion diameter of 20 μm or more and less than 100 μm, detected per steel material volume of 1000 mmby ultrasonic flaw detection, is 12.0 or less, the number of non-metallic inclusions having an inclusion diameter of 100 μm or more, detected per steel material weight of 2.5 kg by the ultrasonic flaw detection, is 2.0 or less, the mass % ratio of (MgO)/(AlO) in the average composition of MgO—AlO-based oxides present in the steel is regulated into a range of 0.25 to 1.50, and the number ratio of the MgO—AlO-based oxides to all oxide-based inclusions is 70% or more.