Martensite heat-resistant steel material and preparation method thereof

Abstract

The invention relates to a martensite heat-resistant steel material. The material comprises, by weight, 0.07%-0.12% of carbon, 8.5%-9.5% of chromium, 2.0%-2.5% of tungsten, 0.2%-0.5% of molybdenum, 2.8%-3.2% of cobalt, 0.03%-0.10% of niobium, 0.16%-0.25% of vanadium, 0.5%-1.0% of copper, 0.010%-0.020% of nitrogen, 0.006%-0.015% of boron, less than or equal to 0.02% of phosphorus, less than or equal to 0.01% of sulfur, less than or equal to 0.5% of silicon, 0.3%-0.7% of manganese, less than or equal to 0.12% of nickel and the balance iron and inevitable impurity elements. According to the process, 95% of coking waste water can be recycled and used as new water. According to martensite heat-resistant steel material, the martensite heat-resistant steel suitable for long-term service at the temperature of 620 DEG C-650 DEG C is provided on the basis of 9Cr series ferrite heat-resistant steel in combination with actual conditions such as industrial mass production. According to the martensite heat-resistant steel material, rare earth elements are not added, the content of W and the ratio of W to Mo elements are optimized, and the content of B is optimized; and compared with existing 9Cr series heat-resistant steel, the impact toughness of the steel material is greatly improved, the cold and hot working performance and the welding performance are obviously improved, and the production cost is obviously reduced.

Description

technical field [0001] The invention relates to the technical field of heat-resistant steel, and provides a novel martensitic heat-resistant steel and a preparation method, which are suitable for manufacturing large-diameter boiler tubes and forgings of ultra-supercritical thermal power units with steam parameters above 630°C. Background technique [0002] Coal-fired power generation is the most important part of my country's power structure both now and in the future. At present, the steam parameters of major ultra-supercritical thermal power units in the world are 600°C, and my country has become the country with the largest installed capacity and total capacity of 600°C ultra-supercritical power plants in operation in the world. In order to further reduce coal consumption, improve thermal efficiency and reduce emissions, coal-fired power transformation and upgrading, ultra-supercritical power plants with high steam parameters are the development direction of new and renov...

AI Technical Summary

Problems solved by technology

[0004] However, the 9Cr series heat-resistant steel in the prior art has deficiencies in impact toughness, hot and cold workability and welding performance.

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