Heat treatment of modern, stabdardized alloys is a scirnce. Doing so with complex formed parts is still a bitch so. Especially big parts. Personally, I think in

Heat treatment of modern, stabdardized alloys is a scirnce. Doing so with complex formed parts is still a bitch so. Especially big parts. Personally, I think induction hardening might work. Well, welded structural parts, even produced in high vilumes, are a rather well understood problem so.