HOLLOW STABILIZER, AND STEEL PIPE FOR HOLLOW STABILIZERS AND METHOD FOR PRODUCTION THEREOF

• Main Authors: TANGE, Akira, TAKAHASHI, Ken, WAKABAYASHI, Yutaka, ISHITSUKA, Tetsuo, KURIMOTO, Kiyoshi, KOYUBA, Motofumi, IWAMURA, Masamichi
• Format: Patent
• Language: English; Hungarian
• Published: 28.02.2019
• Subjects: ALLOYS; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A hollow stabilizer having an excellent fatigue property and higher strength compared to the conventional ones has a chemical composition containing 0.26% to 0.30% of C, 0.05% to 0.35% of Si, 0.5% to 1.0% of Mn, 0.05% to 1.0% of Cr, 0.005% to 0.05% ofTi, 0.0005% to 0.005% of B, and 0.0005% to 0.005% of Ca, wherein; Al, P, S, N, and O are limited to 0.08% or less, 0.05% or less, less than 0.0030%, 0.006% or less, and 0.004% or less, respectively, a remainder of the chemical composition consists of Fe and unavoidable impurities, a value of a product of the Mn content and the S content is 0.0025 or less, and a critical cooling rate Vc90 represented by a predetermined equation is 40°C/s or less; and wherein a metallic structure comprises a tempered martensite, a length of elongated MnS present at a center part in a thickness direction of the hollow stabilizer is 150 µm or less, a HRC is from 40 to 50, a thickness to outer diameter ratio is 0.14 or more, and a depth of a decarburized layer at an inner surface part is 20 µm or less from the inner surface; and a steel pipe for hollow stabilizers used as a material for the hollow stabilizer.