Cr-CONTAINING STEEL EXCELLENT IN THERMAL FATIGUE CHARACTERISTICS

摘要

The present invention provides Cr-containing steel superior in heat fatigue characteristics, that is, Cr-containing steel superior in heat fatigue characteristics, characterized by containing, by mass%, C: 0.01% or less, N: 0.015% or less, Si: 0.8 to 1.0%, Mn: 0.2 to 1.5%, P: 0.03% or less, S: 0.01% or less, Ni: 0.2% or less, Cu: 0.2% or less, Cr: 13 to 15%, Mo: 0.1% or less, Nb: 0.3 to 0.5%, Ti: 0.05 to 0.2%, V: 0.01 to 0.2%, Al: 0.015 to 1.0%, and B: 0.0002 to 0.0010%, satisfying (Nb+1.9×Ti)/(C+N)‰¤50, and having a balance of Fe and unavoidable impurities, wherein a 0.2% yield strength at 800°C after aging at 800°C for 100 hours or more is 20 MPa or more and a drawability value at 200°C is 35% or more and wherein a soluble Nb amount+soluble Ti amount after aging at 800°C for 100 hours or more is 0.08% or more.