Method of evaluating central segregation in steel

A method of evaluating central segregation in steel, the method comprising:

• taking a sample from a steel, the sample having a cross section including a central segregation area;
• measuring an area ratio of an inclusion containing a segregation metal element in a region to be measured including the central segregation area in the cross section;
• and
• evaluating HIC susceptibility of the steel by evaluating central segregation in the steel based on the area ratio measured,
• where letting Mnx1Sy1 be the inclusion and Agx2Sy2 be a compound with a smaller solubility product than Mnx1Sy1, the method further comprising:
• treating the region to be measured in the sample with a solution containing Ag ions to replace Mn located on a surface of the inclusion exposed in the region to be measured with Ag;
• then, measuring an area ratio of Ag in the region to be measured;
• and
• using the area ratio of Ag measured as the area ratio of the inclusion,
• where
• x1 and y1 each denote a numerical value representing a composition ratio of the inclusion, and
• x2 and y2 each denote a numerical value representing a composition ratio of the compound.