| 摘要 |
When contents of Ti, V, Zr, Nb, and C (mass %) are represented as [Ti], [V], [Zr], [Nb], and [C] respectively, a value of a parameter Q represented by“Q=([Ti]/48+[V]/51+[Zr]/91+[Nb]/93)/([C]/12)”is not less than 0.9 nor more than 1.1. A matrix of a metal structure is a ferrite phase, and the metal structure does not include a non-recrystallized structure. An average grain size of ferrite grains constituting the ferrite phase is not less than 10μm nor more than 200μm. A precipitate containing at least one selected from the group consisting of Ti, V, Zr, and Nb exists with a density of 10μm−3 or more in the ferrite grain. An average grain size of the precipitate is not less than 0.002μm nor more than 0.2μm. |
