Well I’m a farmer and I’ve heated up plenty of **** to get something in or out and haven’t ever had a problem. And what do you know it workedRed hot, then oil-quenched? The knuckle, or (more likely) the control arm?
You've heat-treated the control arm. That control arm is now junk. Hardened...brittle.
DO NOT heat the control arm to press-in a ball joint.