Blade for thermodynamic turbines - contains matrix of ferritic iron alloy hardened by dispersion of yttrium oxide and/or titanium di:oxide

摘要

Blade for thermodynamic turbines consists of a ferritic, magneto-elastic matrix (I) contg. a hardening addn. (II) which is a dispersed metal oxide. Matrix (I) is pref. a 12-14% chromium steel; or an iron alloy contg. 18-22% Cr, esp. an alloy contg. 18-22% Cr, 4-5% Al, 0.3-0.7% Ti, rest Fe, with an addn. (I) of 0.4-2%, esp. 0.4-0.6% dispersed yttrium oxide. an alternative pref. blade contains a matrix (I) with compsn. 12-14% Cr, 3-5% Ti, 1.1-1.8% Mo, and balance Fe, with an addn. (II) of 0.3-2% dispersed Y2O3 and/or TiO2. This new material fills the gap existing between ferritic and austenitic blade materials, and combines high creep strength, high corrosion resistance, and high damping capacity.