To provide a high strength and low yield ratio cold rolled steel sheet
having high elongation property and high flange drawing property, or a
plated steel sheet made by plating the same. The high strength and low
yield ratio cold rolled steel sheet or the plated steel sheet made by
plating the same has such a constitution as 0.10 to 0.25% of C, 1.0 to
2.0% of Si and 1.5 to 3.0% of Mn, are contained in terms of weight
percentage, while other elements are controlled such as Al within 0.2%, P
within 0.15% and S within 0.02%, with residual austenite occupying at
least 5%, bainitic ferrite occupying at least 60% (preferably 80% or
more), and polygonal ferrite within 20% (containing 0%), so that a
tensile strength is 980 MPa or higher, while an elongation (El in %), a
flange drawing property (.lamda.in %), a tensile strength (TS in MPa) and
a yield strength (YP in MPa) satisfy the following inequality (1): [(El
.times..lamda..times.TS)/YP].gtoreq.645.