Question about deleting scammed items policy.

Lets say there are trader name "A" who have "some item". But trader named "B" scammed that "some item" from trader "A". Then trader "B" added me and we made trade. Now I have that "some item". I heard steam deletes scammers items. So if steam do some action on trader "B", what will happen that "some item" which i have?

in short, you traded with a scammer for a scammed item. depends how you traded for it. if it was in steam items, that would end up on the scammer being deleted. if you traded for cash (PP, webmoney, w/e) then your item may get deleted.

Now what kind of item was this?

Its not happened. I do lot of trades daily. This is just instantly came to my mind, after i read something about those deleted scammed items. So I wondered what will happen if I buy scammed item. Steam will delete that item from my inventory? So I become victim?

if you buy it with money, steam cannot ascertain you aren't a alt of the scammer.