HEAT RESISTANT STEEL AND ROTOR SHAFT FOR STEAM TURBINE

• Main Authors: SHIMIZU NOBUO, FUKUI HIROSHI, KANEKO RYOICHI, FUJITA TOSHIO, HARADA YASUHIRO, WATANABE YASUO, YAMADA NORIO, SHIGA MASAO, HIDAKA KISHIO, NAKAMURA SHIGEYOSHI, MORISADA TOKIO, TANAKA YASUHIKO
• Format: Patent
• Language: English
• Published: 18.11.1997
• Edition: 6
• Subjects: ALLOYS; BLASTING; CHEMISTRY; ENGINE PLANTS IN GENERAL; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; STEAM ENGINES; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

PROBLEM TO BE SOLVED: To produce a heat resistant steel having >=10kgf/mm creep fracture strength for a hundred thousand hr at 650 deg.C and used for a rotor for a super- critical pressure steam turbine. SOLUTION: This heat resistant steel has a compsn. contg., by weight, 0.05 to 0.20% C, <=0.15% Si, <=1.5% Mn, <=1.0% Ni, 8.5 to 13.0% Cr, <=3.50% Mo, <=3.5% W, 0.50 to 0.30% V, 0.01 to 0.20% Nb, <=5.0% Co, 0.001 to 0.020% B, 0.005 to 0.040% N, 0.0005 to 0.0050% O and 0.00001 to 0.0002% H, in which the Cr equivalent is preferably regulated to <=10 and having the whole tempered martensite metallic structure.