PRODUCTION OF STEEL BOLT

• Main Authors: TANIOKA SHINICHI, MAKIMAE TATSUMI, MATSUI KEIKO
• Format: Patent
• Language: English
• Published: 16.08.1994
• Edition: 5
• Subjects: ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL; BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINEERING ELEMENTS AND UNITS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GRINDING; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; POLISHING; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; THERMAL INSULATION IN GENERAL; TRANSPORTING; WEAPONS

PURPOSE:To improve delayed fracture resistance so as to improve fatigue strength in the case of producing a steel bolt as a high strength bolt, by decomposing phosphate film, which is formed on the surface of a steel bolt member in a lubricating film treatment process, at thermal treatment so as to evade such a situation of infiltrating phosphor component into the inside of the steel bolt member. CONSTITUTION:In lubricating film process, phosphate film is formed on a surface of a steel bolt member, in a bolt forming process, a screw part is formed, in a micro shot process, shot particles are shot on a surface part of the steel bolt member where phosphate film is formed so as to reduce phosphate film, and it transfers to a thermal treatment process.