Hot dip galvannealed steel sheet

A hot dip galvannealed steel sheet, comprising a base steel sheet and a plating layer, wherein

• the base steel sheet has a chemical composition containing, by mass %,
• C:
• 0.0005 to 0.0100%,
• Si:
• 0.01 to 0.50%,
• Mn:
• 0.01 to 2.00%,
• P:
• 0.100% or less,
• S:
• 0.0100% or less,
• N:
• 0.0200% or less,
• Ti:
• 0.040 to 0.180%,
• Nb:
• 0 to 0.100%,
• B:
• 0.0005 to 0.0100%,
• Al:
• 0 to 1.000%,
• Cu:
• 0 to 1.000%,
• Cr:
• 0 to 2.000%,
• Ni:
• 0 to 0.500%,
• Mo:
• 0 to 3.000%,
• W:
• 0 to 0.100%,
• V:
• 0 to 1.000%,
• O:
• 0 to 0.020%,
• Ta:
• 0 to 0.100%,
• Co:
• 0 to 3.000%,
• Sn:
• 0 to 1.000%,
• Sb:
• 0 to 0.500%,
• As:
• 0 to 0.050%,
• Mg:
• 0 to 0.050%,
• Zr:
• 0 to 0.050%,
• Ca:
• 0 to 0.0500%,
• REM:
• 0 to 0.0500% and
• a balance of Fe and impurities,
• a standard deviation SD found under the following Condition 1 is 0.40 or less, and
• an interval I found under the following Condition 2 being 50 μm or less:
• Condition 1:
• An electron probe microanalyzer (EPMA) is utilized to divide a 2 mm square region at a surface of the base steel sheet into a 400×400 plurality of areas for elemental mapping and identify the Mn intensities at the individual areas;
• the standard deviation SD is found from the distribution of the number of detection points of the Mn intensities at the square region;
• Condition 2:
• An electron probe microanalyzer (EPMA) is utilized to divide a 2 mm square region at a surface of the base steel sheet into a 400×400 plurality of areas for elemental mapping and identify the Mn intensities at the individual areas;
• the average value MIave of the Mn intensities at the square region is identified;
• the square region is divided into 400 regions in the direction perpendicular to the rolling direction to obtain 400 divided regions;
• among these divided regions, those with 50% or more areas exhibiting Mn intensities 34% or more higher than the average value MIave are defined as “first regions”;
• among these divided regions, those with 50% or more areas exhibiting Mn intensities 34% or more lower than the average value MIave are defined as “second regions”;
• the interval I of first regions adjoining each other across second regions in the square region is found.