HIGH-STRENGTH AUSTENITIC HEAT-RESISTING STEEL WITH EXCELLENT WELDABILITY AND GOOD HIGH-TEMPERATURE CORROSION RESISTANCE

摘要

A high-strength austenitic heat-resisting steel that has excellent weldability and good high-temperature corrosion resistance and can exhibit excellent performance when used as the material of boilers to be used under the conditions becoming more and more severe. The steel comprises less than 0.02 % (by mass, the same will apply hereinbelow) of carbon, at most 1.5 % of silicon, 0.3-1.5 % of manganese, at most 0.02 % of phosphorus, at most 0.005 % of sulfur, 18-26 % of chromium, 20-40 % of nickel, 0.5-10.0 % of tungsten, 0.05-0.4 % of niobium, 0.01-0.2 % of titanium, 0.003-0.008 % of boron, 0.05-0.3 % of nitrogen, and if necessary at least one member of 0.5-2.0 % of molybdenum and/or 0.001-0.05 % of magnesium, 0.001-0.05 % of calcium and 0.001-0.15 % of rare earth element (REM), and the balance consisting of iron and inevitable impurities.