High-temperature seamless ferritic alloyed steel and production method thereof

Abstract

The invention relates to high-temperature seamless ferritic alloyed steel and a production method thereof. The steel is characterized by consisting of the following chemical components in percentage by mass: 0.05 to 0.09 percent of C, 0.20 to 0.50 percent of Si, 0.10 to 0.60 percent of Mn, 1.95 to 2.55 percent of Cr, 1.50 to 1.75 percent of W, 0.001 to 0.005 percent of B, 0.005 to 0.06 percent of Ti, 0.05 to 0.30 percent of Mo, 0.02 to 0.08 percent of Nb, 0.20 to 0.30 percent of V, less than or equal to 0.015 percent of N, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.015 percent of total Al, less than or equal to 0.003 percent of O, and the balance of Fe and inevitable impurities. The ratio of Ti to N is more than or equal to 3.5. A normalizing and tempering technology is adopted in heat treatment, the normalizing temperature is 1,040 to 1,080 DEG C, the heat preservation time is not less than 1.5 minutes per 1 milliliter of wall thickness and is not less than 30 minutes, and cooling is performed at an austenitizing speed by accelerating air; and the tempering temperature is 730 to 800 DEG C, the heat preservation time is not less than 1 hour, and cooling is performed in still air. The method is high in production efficiency, high in economic benefits and suitable for large-scale production, and has high popularization value.

Description

technical field [0001] The invention relates to a high-temperature seamless ferritic alloy steel and a production method thereof, belonging to the field of metallurgical materials. Background technique [0002] With the development of the electric power industry and the increasing global concern for environmental issues, saving primary energy, strengthening environmental protection, reducing harmful exhaust emissions, and reducing the global warming effect have attracted great attention at home and abroad. From the design and actual operation of power plant boilers, people have gradually reached a consensus that only by increasing steam parameters (pressure and temperature) can the thermal efficiency of the unit be effectively improved, coal consumption reduced, harmful gas emissions reduced, and environmental protection and energy conservation met. Require. Therefore, power plant boilers all over the world are developing in the direction of large capacity and high paramete...

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