Convictions are expunged. Arrest records are forever. If you are willing to retain an attorney who is able to show that: 1) the record of your arrest and any charges against you is of insufficient probative value to law enforcement and other authorities in comparison to the prejudicial impact it is having upon your life, career, etc; and 2) that you are extremely unlikely to commit any similar or other illicit criminal act, then you might have a chance at having your arrest record sealed by a judge.
It is actually easier to expunge a felony. Of course the arrest records of all who are charged as minors in the US are supposedly "sealed". However, it has been my experience as an attorney that police, state and federal investigators are often able to access even records that have been sealed as well as, convictions that have been expunged.
Good luck.