All-or-nothin' burn

摘要

Dear Doc: I use water-based coolants when creep-feed grinding hardened steel. I get burn, but it doesn't appear gradually or come and go. I get no burn and then-wham!-the workpiece is burned to death, along with all subsequent workpieces until I dress the wheel again. Why is the burn not gradual? The Doc Replies: It sounds like you're getting what's called "burn-out," or "film boiling."