BOLT MADE OF TITANIUM ALLOY AND METHOD FOR PRODUCING BOLT MADE OF TITANIUM ALLOY HAVING TENSILE STRENGTH OF AT LEAST 800 MPa

• Main Authors: SUMITOMO HIDEAKI, HORIMURA HIROYUKI, DOI KOUSUKE
• Format: Patent
• Language: English
• Published: 12.10.2006
• Subjects: ALLOYS; BLASTING; CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS ANDNON-FERROUS ALLOYS; CHEMISTRY; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; ENGINEERING ELEMENTS AND UNITS; FERROUS OR NON-FERROUS ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS,WHEELS, RINGS, BARRELS, BALLS; MECHANICAL ENGINEERING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; PERFORMING OPERATIONS; PUNCHING METAL; THERMAL INSULATION IN GENERAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

PROBLEM TO BE SOLVED: To provide a bolt made of a titanium alloy which can be subjected to cold forging and is inexpensive, and to provide a method for producing the same. SOLUTION: In the figure (a), a stock piece 20 is composed of a Ti-Fe-O based alloy comprising, by mass, 0.6 to 1.4% Fe and 0.24 to 0.44% O, and the balance titanium with inevitable impurities. In the stock piece 20, the diameter of the part to form into a shaft part is reduced by drawing. In the figure (b), the drawn part 21 is subjected to head upset forging, thus a large-diameter part 22 is made into a bolt head. The figure (c) shows the obtained headed shaft member 25, and, in the headed shaft member 25, one end of the shaft part 23 is integrally provided with a bolt head 26 fitted with a flange 27. Since this invention is composed of the Ti-Fe-O based alloy, cold plastic working is made possible, working cost can be reduced, and stock cost can be reduced. COPYRIGHT: (C)2007,JPO&INPIT