摘要:
The present invention is directed to a steam turbine rotor which comprises an iron base alloy containing 0.05 to 0.2 wt % of carbon, 0.1 wt % or less of silicon, 0.05 to 1.5 wt % of manganese, more than 8.0 wt % to less than 13 wt % of chromium, less than 1.5 wt % of nickel, 0.1 to 0.3 wt % of vanadium, 0.01 to 0.1 wt % of niobium, 0.01 to 0.1 wt % of nitrogen, 0.02 wt % or less of aluminum, less than 0.50 wt % of molybdenum and 0.9 to 3.0 wt % of tungsten; contents of molybdenum Mo and tungsten W satisfying the following formulae0.75.ltoreq.1/2W+Mo and3.ltoreq.W/Mo;a .delta.-ferrite phase and a large grain boundry carbide being scarcely contained basically in the metallic structure; a matrix of martensite being formed therein.
摘要:
A titanium alloy having a high degree of internal friction and suitable for rotating blades of turbomachines is composed of 5.5 - 6.75% Al, 1 - 5% V, 1 - 5% Mo, V plus Mo being greater than or equal to 5%, and the balance Ti and usual impurities, all by weight. A method of heat-treating the alloy comprises maintaining the same at a temperature not lower than 125.degree. C below its .beta. transformation point for a predetermined period of time and then rapidly cooling the alloy.
摘要:
In a process for heat treating titanium alloys, and .alpha.+.beta. titanium alloy, heated and held in a temperature range above 500.degree. C. and below the .alpha.+.beta./.beta. transformation point, and then quenched, is further aged at a low temperature in the range between 50.degree. and 300.degree. C.