Hmm. No.
If that smacks of Vision to you (i.e. "I'm so above society that its rules don't apply to me"), I'm hesitant to see what your idea of Law even means.Lawful good (LG) creatures can be counted on to do the right thing as expected by society.
Do you _really_ think that describes Tony Stark? Post- Iron Man 3, I can _kinda_ see that, but I think he still fits better with...Neutral good (NG) folk do the best they can to help others according to their needs.
This one is a little more interesting because, yes, Cap does act as his conscience directs. To say that it's "with little regard for what others expect" is pushing it, though, especially because he is often expected to do evil actions, or at least "not good". As such, he does the right thing as expected by _the people_ and society at large, not necessarily the people running it.Chaotic good (CG) creatures act as their conscience directs, with little regard for what others expect.
To reCap (ha! pun), Vision is not Lawful Good, Iron Man is likely Chaotic Good, and Cap is probably not Chaotic Good.