CARBURIZED SHAFT COMPONENT

• Main Authors: IWASAKI, Tatsuya, SUENO, Hidekazu, WATARI, Koji
• Format: Patent
• Language: English; French; German
• Published: 15.04.2020
• Subjects: ALLOYS; BEARINGS; BLASTING; CHEMISTRY; ELEMENTS OR CRANKSHAFT MECHANISMS; ENGINEERING ELEMENTS AND UNITS; FERROUS OR NON-FERROUS ALLOYS; FLEXIBLE SHAFTS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; SHAFTS; THERMAL INSULATION IN GENERAL; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

A carburized shaft part having a predetermined composition, a C content at a surface layer part of a mass% of 0.60 to 1.00%, at least one hole at an outer circumferential surface, a total volume ratio of martensite and retained austenite of 97% or more at a structure at a position of a 1 mm depth from the outer circumferential surface in an axial direction of the hole and a position of a 20 µm depth from the surface of the hole, a maximum retained austenite volume ratio (R1) of 10.0 to 30.0% at a position of a I mm depth from the outer circumferential surface in the axial direction of the hole and a range up to a 200 µm depth from the surface of the hole, and a retained austenite reduction ratio of 20% or more found from R1 and the retained austenite volume ratio (R2) at a position of a 1 mm depth from the outer circumferential surface in the axial direction of the hole and a position of a 20 µm depth from the surface of the hole by the formula (A): Δγ=(R1-R2)/R1×100.