Just make sure you are careful when cleaning them. A wire brush is fine but don't scrape them. A metal scraper will cut into the porcelain (I know from experience with my porcelain coated cast iron). I imagine that is why there are wood scrapers but don't know for sure since I've never used one.
Thanks for the suggestions. I think my grate is probably just porcelain covered steel. I don't think its cast iron.
It does clean very easy...just a little spay of cleaner and some Hot water with a little brushing and its good to go.