It's about rust on my spatter guard for frying pan?

I suspect it has used up its useful life. It is common for companies to take cheap screens and coat them with a layer of stainless steele. The obvious problem is after several years of use the coating is gone and yes you are probably right its rust showing its ugly head. I would dump your spatter guard and try to find a more quality one. There are good companies out there you just need to find one. Keep in mind stainless steel is about 3 times the cost so factor that in your research. good call though rust in the food does not promote iron and is not good for the human body. I typed in splatter guard in the websearch box you can research splatter guards right from your computer and order one online. there seemed to be some in the 20 dollar range that would more than likely last for many years if thats what you want.

Sounds like burnt on oil,you can get industrial cleaner and give it a good scrub,stainless steel will still stain it's stain- less bit misleading.

It might be for the food and drink category but you put it in "Cars & Transportation"