To see fine grain, many of us will heat treat a "coupon", or piece of steel, heat treat it, and break it. That tells a whole lot. It should look silky, unable to really see any "grain". If you see grain like sand, it's either a bad HT, steel, or both.

It was interesting to see the O1 rating as it's one of the steels used in razors, along with 1095.