They are very nice but I can't see or feel any porcelain on it.

Your cooking grids have a matte finish and look like they do not have a coating. The rough texture is a result of there being no enamel in the porcelain. The porcelain is able to adhere to the surface of the cast iron better, thus making it harder to chip. We recommend you not using a stainless steel brush to clean your new cooking grids. Stainless steel is too abrasive and will scratch any coated grids. Scratches become cracks and that is where your rust comes from.