If aluminum, the car manufacturers use forged aluminum steering parts, probably for the grain flow and fatigue strength.
If "steel" parts are made of steel forgings, they can be heated and bent without too much strength reduction, but if heat treated cast iron (aduser-ferrous) or nodular iron is used, it is advised not to heat, bend, weld or alter the shape of the piece. For drag-racing anything is done, but the safety factor is challenged every time. Maybe you are "better safe than sorry".
Thanks.