Rotor steel for super clean turbine with excellent manganese-containing thermostability resistance and manufacturing method thereof

摘要

More particularly, the present invention relates to a rotor steel for super clean turbine having excellent resistance to manganese-containing embrittlement resistance and a method for producing the rotor steel. (P), 0.002% or less of sulfur (S), 1.60 to 2.00% of chromium (Cr), 0.35% or less of molybdenum (Mo), 3.5 to 4.00% of nickel (Al), 0.005% or less of arsenic (As), 0.005% or less of tin (Sn), or 0.002% or less of antimony (Sb) (H) of not more than 1.5 ppm, oxygen (O) of not more than 35 ppm and nitrogen (N) of not more than 80 ppm, and the balance of iron (Fe) (3.5% NiCrMoV) steel which is a material for a low-pressure rotor shaft for a steam turbine specified in ASTM A470 Class 7 which has been used conventionally. Resistance to temper embrittlement can be improved and the present invention steel can be used even at a temperature of 350C or higher to improve the thermal efficiency of the existing power plant. Further, according to the extension of the life of the material, It is possible to use it as a low-pressure turbine rotor without changing the material in a supercritical pressure power plant, which is a next generation power plant, and to use it as a gas turbine compression rotor shaft material.