HIGH-STRENGTH COLD-ROLLED STEEL SHEET, HIGH-STRENGTH PLATED STEEL SHEET, AND PRODUCTION METHODS THEREFOR

The present invention addresses the problem of: obtaining a high-strength cold-rolled steel sheet and a high-strength plated steel sheet having a tensile strength (TS) of 780 MPa or higher and excelling in ductility, stretch-flangeability, and in-plane stability of stretch-flangeability; and providing effective production methods for same. This high-strength cold-rolled steel sheet has a steel structure containing a specific component composition, ferrite at an area ratio of 50-80%, martensite having an average grain size of 2.5 [mu]m or less at an area ratio of 8% or less, retained austeniteat an area ratio of 6-15%, and tempered martensite at an area ratio of 3-40%, and where the value of the ratio fM/fM+TM of the area ratio fM of the martensite and the total area ratio fM+TM of the martensite and the tempered martensite is 50% or less and the standard deviation of crystal grain sizes of the martensite is 0.7 [mu]m or less across a total of five sites, namely, a width-center part located at the center in th