HEAT TREATMENT METHOD

• Main Authors: MINOUE JUNJI, KAMIBAYASHI MASAHIRO, MASUTANI YUSUKE
• Format: Patent
• Language: English
• Published: 16.08.2012
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

PROBLEM TO BE SOLVED: To provide a heat treatment method capable of induction-heating a portion required to be heat-treated, and also capable of induction-heating concurrently a portion not required to be heat-treated, so as to be discolored, when induction-heating an object to be heat-treated having the portion required to be heat-treated, and the portions of various sizes and shapes not required to be heat-treated, and capable of confirming whether the object to be heat-treated is heat-treated or not, by observing the portion not required to be heat-treated.SOLUTION: A heating coil 2 electrified with an alternating current is approached to a large diameter part 10, to induction-heat the large diameter part 10, when heat-treating again the large diameter part 10 of a work 5 having the heat-treated large diameter part 10 and a small diameter part 6 not heat-treated. At that time, a magnetic induction body 7 composed of a material of high magnetic permeability is approached therein or brought into contact to/with the small diameter part 6, and the small diameter part 6 is induction-heated to be discolored. The large diameter part 10 is poor in a color change even when induction-heated again, the small diameter part 6 is discolored because heat-treated for the first time, and the reheat-treatment of the large diameter part 10 of the work 5 is determined based on the discoloration of the small diameter part 6.