High-temperature-resistant stainless steel

Abstract

The invention relates to high-temperature-resistant stainless steel, which is prepared from the components in percentage by mass: 0.01 to 0.05 percent of C, 0.10 to 0.3 percent of Si, 2.10 to 2.50 percent of Mn, less than or equal to 0.0020 percent of S, less than or equal to 0.002 percent of P, 0.01 to 0.02 percent of Al, 19.0 to 22.0 percent of Ni, 22.0 to 23.50 percent of Cr, 0.01 to 0.02 percent of Nb, 0.050 to 0.60 percent of Ta, 0.001 to 0.20 percent of Nd, 0.0002 to 0.00050 percent of B, 0.03 to 0.05 percent of N, 0.02 to 0.05 percent of rare earth Ce, and the balance iron and inevitable impurities, wherein a value obtained by dividing the content of the Nb to the content of the Ta is 4.2 to 5.5, and Ta plus 0.5Nd is equal to 0.050 to 0.70 percent. The austenite grain size is 20 to25 micrometers.

Description

technical field [0001] The invention relates to high-temperature resistant stainless steel, in particular to high-temperature resistant stainless steel used in high-temperature and strong oxidizing environments such as boiler tubes for coal power generation. Background technique [0002] Among various energy resources in my country, coal resources are the most abundant. Coal-fired thermal power generation units account for more than 75% of the total capacity of generating units, occupying a dominant position. In recent years, with the rapid development of my country's national economy, the demand for electricity has also increased significantly. The development of high-parameter, large-capacity ultra-supercritical power generation technology has become the only way for my country's thermal power units to improve energy utilization and reduce pollutant emissions. However, increasing the parameters and capacity of thermal power units puts forward very high requirements on the...

AI Technical Summary

Problems solved by technology

Existing high-temperature-resistant stainless steel grades and their steel pipes do not meet the above requirements, such as 1Cr18Ni9 used in subcritical units and 1Cr19Ni11Nb stainless steel and steel pipes widely used in supercritical units. Due to their low high-temperature strength, the finished steel pipes have coarse grains (Generally 4-7 grades), poor high temperature steam corrosion resistance and other shortcomings, can not meet the requirements of ultra-supercritical boilers for the use of materials

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