who plays bad guy in iron man 2
Justin Hammer
Plot
Stark's rival, Justin Hammer, fakes Vanko's death while breaking him out of prison and asks him to build a line of armored suits to upstage Stark. 
UNANSWERABLE Russian scientist Ivan Vanko. UNANSWERABLE
Iron Man 2
Introduction
Meanwhile, Russian scientist Ivan Vanko uses his own version of the technology to pursue a vendetta against the Stark family.
wiki:6352043
Iron Man 2 [SEP] Plot
The Soviets sent Anton to the Gulag. Fury gives Stark some of his father's old material. Tony discovers a hidden message in the diorama of the 1974 Stark Expo; it proves to be a diagram of the atomic structure of a new element. With the aid of his A.I., J.A.R.V.I.S., Stark synthesizes it. When he learns that Vanko is still alive, he places the new element in his arc reactor and ends his palladium dependency.