During the quarantine I have not been driving a lot. I take my car out of the parking lot maybe once every 7-10 days, I park on the roof and as I drive down (many right turn rights) I have scrapping (like metal grinding noise). This happens if I apply the brakes or even if I do not as I turn right or left. No noise when I drive straight. The noise eventually goes away after like 10 min of of driving. My car has about 26,000 miles (purchased new) I would say about 8000 are from long road trips. I do live in NYC only drive on average 50 miles a week. I did have the rear breaks serviced in December of 2019. The noise is coming from the front. Could it just be rusty rotters (that clean up after a bit of driving)?
It sounds like some rust on the rotors from sitting. Nothing to worry about.
While it is the most common issue is rust there is other components at play like pads, brake grease that is used on the back of pad and caliper pins, and the caliper itself, if it is a floating caliper instead of a fixed caliper.
A floating calipers works by pressing one side into the caliper and then pulling the other side to match. If the caliper is sticking after from sitting it could free it up to float more easily after it is used. If the caliper is sticking from sitting causing to pads pressings against the rusty rotor which could the grinding noise.
I wouldn’t dismiss other possible causes. I would take it to a trusted mechanic to make sure. As obviously brakes are very important.
I am sure others will chime in and so take my advice with a grain of salt as I am usually wrong and others will correct me.