The short of it is mainly no. But yes as long as you can prove you are the author where you originally posted it. Like going to the OP and editing it to say I have republished this on steemit.com and throw in the link. And also make a note on here that you are republishing it here and link it, That way they are crossed linked and no one can say you stole the material.
If the said article is on here mainly no, unless you have a series going where it may end or start the same way. But it isn't 100% copied. For instance, @papa-pepper has a couple of different series he does, and pretty much some of the info is the same for the series. I do contest and giveaways and my rules are nearly always the same. Hope that helps clear it up.