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:
Jun. 24, 1980
Filed:
Sep. 13, 1978
Yoshihiro Kajinaga, Chiba, JP;
Minoru Nitta, Chiba, JP;
Ichio Sakurada, Ichihara, JP;
Shunji Ito, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
A process for producing low-oxygen iron-base metallic powder are disclosed. The low-oxygen iron-base metallic powder is produced in a shaft-type apparatus comprising a preheating zone and an induction heating zone by alloying and/or admixing iron-base metallic raw powder to be subjected to a final reduction, which has an apparent density corresponding to 16 to 57% of theoretical true density, an oxygen content of not more than 6% by weight and a particle size of not more than 1 mm, with carbon or carbonaceous granule in an amount corresponding to not more than a target alloying carbon content of a final product (% by weight)+ an oxygen content of the powder just before the final reduction (% by weight).times. 1.35 to form a starting powder, preheating the starting powder at a temperature of 780.degree. to 1,200.degree. C. in a non-oxidizing atmosphere having a thermodynamically calculated oxygen partial pressure of not more than 2.1.times.10.sup.-1 mmHg and a dew point of not more than +5.degree. C. in the preheating zone to form a preheated and sintered cake (P-cake) with cylindrically sintered shell layer wherein the volume ratio of the shell layer is at least 20%, induction heating the P-cake at a temperature of 850.degree. to 1,400.degree. C. in the same atmosphere by applying an alternating power of 50 Hz to 500 kHz from power supply to effect deoxidation and decarburization to form an induction heated cake (I-cake), and then cooling and pulverizing the I-cake.