| 摘要 |
PURPOSE:To obtain a distance piece for gas turbine having high creep rupture strength at 400-450 deg.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 deg.C V notch Charpy impact value are respectively specified. CONSTITUTION:The distance piece for gas turbine is composed of the martensitic steel in which 100,000hr creep rupture strength at 450 deg.C is >=45kg/mm<2> and 20 deg.C V notch Charpy impact value is >=5kg-m/mm<2>. In order to obtain the above high creep rupture strength, it is necessary to regulate the components of the martensitic alloy steel to the following compositional ranges, respectively: 0.05-0.15% C, 0.1-0.3% V, <=1% Si, 0.02-0.2% Nb, <=1.5% Mn, 0.02-0.1% N, 1-2.5% Ni, and the balance Fe with impurities. The distance piece of this invention has above-mentioned characteristics, so that it has a marked effect of high reliability against high-temp. fracture.
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