HOT-ROLLED STEEL SHEET

摘要

A hot-rolled steel sheet including predetermined components, in which the amounts of Cr and Al added satisfy Expression (1) below, a metallographic structure has, by % by volume, a ferrite fraction of more than 90% and 98% or less, a martensite fraction of 2% to less than 10%, and, a fraction of a residual structure made of one or more of pearlite, bainite, and residual austenite being less than 1%, the ferrite has an average circle-equivalent diameter of 4 µm or more and a maximum circle-equivalent diameter of 30 µm or less, and the martensite has an average circle-equivalent diameter of 10 µm or less and a maximum circle-equivalent diameter of 20 µm or less. $\left[\mathrm{Cr}\right]\times 5+\left[\mathrm{Al}\right]\ge 0.50\mathop{\mathrm{image}}$;Here, in Expression (1), [Cr] represents an amount of Cr (mass%), and [Al] represents an amount of Al (mass%).