Steel for steam-temperature ultra-supercritical thermal power unit and preparation method thereof

Abstract

The invention relates to steel for a steam-temperature ultra-supercritical thermal power unit and a preparation method thereof, belonging to the technical field of heat resistant steel. The steel comprises the following chemical compositions by weight percentage: 0.06-0.10 percent of carbon, 0.1-0.5 percent of silicon, 0.2-0.8 percent of manganese, not more than 0.004 percent of phosphorous, not more than 0.002 percent of sulfur, 8.0-9.5 percent of chromium, 2.5-3.5 percent of tungsten, 2.5-3.5 percent of cobalt, 0.03-0.07 percent of niobium, 0.10-0.30 percent of vanadium, 0.80-1.20 percent of copper, 0.006-0.010 percent of nitrogen, 0.010-0.016 percent of boron, 0.01-0.04 percent of rare-earth cerium, not more than 0.01 percent of nickel, not more than 0.005 percent of aluminum, not more than 0.01 percent of titanium, not more than 0.01 percent of zirconium and the balance of ferrum and inevitable impurity elements. The steel has the advantages that the steel can be used for preparing G115 steel of 650 DEG C of steam-parameter ultra-supercritical thermal power unit and a large-diameter boiler tube thereof, and the room-temperature mechanical property, the impact property, the high-temperature mechanical property and the permanence property of the steel are much higher than those of P92 steel in the Gb5310 and ASME standard.

Description

technical field [0001] The invention belongs to the technical field of heat-resistant steel, and in particular provides a steel for steam temperature ultra-supercritical thermal power units and a preparation method thereof, which can be used for the preparation of G115 steel and large-diameter boiler tubes for ultra-supercritical thermal power units with steam parameters of 650°C. Background technique [0002] With the rapid development of my country's economy, the shortage of resources and energy has become a bottleneck problem. In recent years, the country’s large demand for electricity and the rapid growth rate have greatly exceeded the country’s original electricity development plan, so that the forecast for electricity demand in 2020 had to be revised several times, and the planned total installed capacity has been adjusted from 960 million kWh to 1.6 billion kWh. For a long period of time in the future, thermal power generation with coal-fired generating units as the ...

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Problems solved by technology

[0005] The U.S. patent US20090007991A1 filed by Japan’s Takashi Sato et al. introduced a 9% Cr ferritic heat-resistant steel 9Cr0.5Mo1.8WNbVN based on P9

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