Steel, the Indestructible Man #01-05
When he arrives back to the States, he finds that Germany has invaded Poland and he leaves Princeton to join the United States Marines. His girlfriend Gloria Giles is against his decision and leaves him for that decision, but it is soon after entering the war that that he is blown up trying to stop some saboteurs.
This is when Gloria decides to come back and Steel is rebuilt to comeback from his injuries as well. This turns him into a super-powered being, but because of the injury he will have to stay stateside at a desk job. This does not sit well so he makes his costume and becomes the Superhero Steel. As Steel he fight several saboteurs for months trying to find the head man Baron Death.