The phrases mentioned in the question are not words that count as a vow (nadhr), either explicitly or implicitly.

No expiation is required for the oath that you do not mean; rather you say it as a matter of habit without intending it, because you are used to doing that and you do not intend to swear an oath as such. As for the oath that you intend and say deliberately, then expiation is required [if you break the oath], whether you meant to commit yourself to it or meant it as a threat.