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:
Dec. 25, 2018
Filed:
Oct. 02, 2013
Ntn Corporation, Osaka-shi, Osaka, JP;
Takumi Fujita, Kuwana, JP;
Kazuhiro Yagita, Kuwana, JP;
NTN CORPORATION, Osaka, JP;
Abstract
A heat treatment method includes the steps of: measuring a hot section temperature; measuring a cold section temperature; adjusting a temperature of a workpiece; and determining quenching timing for the workpiece. The step of adjusting a temperature includes the steps of: heating the workpiece by high energy heating; and controlling heating based on the hot section temperature. In the step of determining quenching timing, the quenching timing is determined based on the hot section temperature and the cold section temperature so as to achieve a predetermined solid-dissolved state of carbon on a TTA diagram in the entire workpiece. The TTA diagram is derived by a calculation formula obtained by conducting a regression analysis of a result of an experiment performed for examining a relation between the solid-dissolved state of carbon and each of a heating temperature and a heating time of steel.