Hi there!  Sure:

The riff is: one strum B5 then one strum D5. Next is another strum on D5 then 2 strums on E5.
Then it goes one strum G5 to one strum F#5 (faster strums) played a total of 3 times.
Now back to D5 for 2 strums and then E5 for 2 strums.

B5 is: 2nd fret of A string, 4th fret of D string.
D5 is: 5th fret of A string, 7th fret of D string.
E5 is: 7th fret of A string, 9th fret of D string.
G5 is: 10th fret of A string, 12th fret of D string.
F#5 is: 9th fret of A string, 11th fret of D string.

You could also do a google search : "iron man tab" and find the tab for it.

Hope this helps! Let me know how it goes!