Patent ID: 11060157

Abstract:
Provided are coated steel sheets, production methods therefor, and so forth, the coated steel sheets having a tensile strength of 440 MPa or more, good formability, and good aging resistance. A steel sheet of the present invention includes a specific component composition and a steel microstructure having an area fraction of a ferrite phase of 80% or more and 95% or less, an area fraction of pearlite of 5% or more and 20% or less, and an average ferrite grain size of 5 μm or more and 20 μm or less, in which in a ferrite grain size histogram, the average grain size of the largest 20% of ferrite grains in terms of grain size is 10 μm or more, and the pearlite has an average lamellar spacing of 200 nm or less, the area fraction, the average ferrite grain size, and the lamellar spacing being determined by microstructure observation.