PURPOSE: To obtain the titled compressor blade having high creep rupture strength at 400W450°C and also having high toughness at room temp. by composing it of a martensitic alloy steel in which creep rupture strength at prescribed temp. and 20°C V notch Charpy impact value are specified, respectively.
CONSTITUTION: The compressor blade for gas turbine is composed of the martensitic alloy steel in which 100,000hr creep rupture strength at 450°C is ≥45kg/mm 2 and 20°C V notch Charpy impact value is ≥5kg-m/cm 2 . In order to obtain above-mentioned rupture strength, it is necessary to regulate the components of the above alloy steel to a composition consisting of 0.05W0.15% C, 0.1W0.3% V, ≤1% Si, 0.02W0.2% Nb, ≤1.5% Mn, 0.02W0.1% N, 1W2.5% Ni, and the balance Fe with impurities. The above compressor blade of this invention is remarkably excellent in creep rupture strength as mentioned above and has a marked effect of high reliability against high-temp. fracture.