Either you tire is rubbing or if its a front wheel drive it could be you "CV" axle's... Other than that i don't know i hope that helps?
if its a front wheel drive vehicle then it could be the axels
A few things could be causing a grinding sound when turning. It could be a cv axle, ball joint, tie rod end, or bracket pin steering.
Bad wheel bearings usually cause a grinding noise, and are known to only cause it when turning.
Have your brakes checked, rust or wear on brakes can cause grinding when turning.
possibly your wheel bearing is on its way out
The bearings on the alternator could be going bad. Remove the belt from the alternator then spin the alternator by hand to listen for grinding.
not sure sound like it comes from front suspension
A bad transmission. The sound is from metal grinding on eachother.
Check out the bearings in the steering column and the knuckles in the steering shaft
A bad wheel bearing also when turning it sounds worst or straight driving
scraping sweeking grinding clicking sounds like something is grinding will be most apparent when turning
If you vehicle is front-wheel drive, more than likely, that grinding crunching sound when you turn is coming from the CV joints.