HEAT-RESISTANT ALLOY CAPABLE OF DEPOSITING FINE TI-NB-CR CARBIDE OR TI-NB-ZR-CR CARBIDE

摘要

2 0 ABSTRACT HEAT RESISTANT ALLOY ADAPTED TO PRECIPITATE FINE TI-NB-CR CARBIDE OR TI-NB-ZR-CR CARBIDE A HEAT RESISTANT ALLOY COMPRISING, IN BY WEIGHT, OVER 5 0. 6TO NOT MORE THAN 0. 9OF C, UP TO 2. 5OF SI, UP TO 3. 0OF MN, 20 TO 2BOF CR, 8 TO 55OF NI, 0.01 TO 0.8OF TI AND 0.05 TO 1.5OF NB, THE BALANCE BEING FE AND INEVITABLE IMPURITIES, THE VALUE OF (TI + NB)/C BEING 0.12 TO 0.29 IN ATOMIC RATIO. WHEN THE ALLOY FURTHER CONTAINS UP TO 0.5OF ZR, THE VALUE OF (TI + NO + ZR) /C IS 0 . 12 TO 0. 2 9 IN ATOMIC RATIO. WHEN THE ALLOY IS HEATED AT A TEMPERATURE OF AT LEAST ABOUT 800 DEGREES C, A FINE TI-NB-CR CARBIDE OR TI-NB-ZR-CR CARBIDE PRECIPITATES WITHIN GRAINS TO THEREBY RETARD CREEP DEFORMATION AND GIVE AN IMPROVED CREEP RUPTURE STRENGTH. THE 15 ALLOY IS THEREFORE SUITABLE AS A MATERIAL FOR HYDROGEN PRODUCTION REFORMING TUBES. FIG. 2