SB-08-2(034) Development of Precipitation Strengthened 15Cr Ferritic Creep Resistant Steel(Advanced Heat Resistant Steels)

概要

論文の詳細を見る
In order to develop new high strength ferritic creep resistant steel, effects of alloying elements of V, Nb, W and Co on a creep strength of full annealed 15Cr ferritic steel has been investigated. Increase in V and Nb contents does not improve the creep strength. On the other hand, increases in creep strength with increase in W content from 3 to 6mass% and addition of 3mass% of Co have been obviously observed. About 10 times and 30 times longer time to rupture than that of the base steel at 923K-100MPa have been obtained by increase in W content from 3 to 6mass% and addition of 3mass% of Co, respectively. Moreover, significant improvement of creep strength that is about two orders of magnitudes in time to rupture, has been obtained by the combination of increase in W content and addition of Co. Creep rupture strength of the steel strengthened by 6mass% of W and 3mass% of Co is almost the same as that of ASME T92 steel. Since Cr content of conventional ferritic creep resistant steels is less than 12%, oxidation resistance of the 15Cr ferritic steel is better than those of conventional one. It has been concluded that a full annealed 15Cr ferritic creep resistant steel should be one of the candidate materials for new Ultra Supercritical (USC) power plant in the 21st century.
社団法人日本機械学会の論文
2001-06-03