Is the "burn" produced during grinding due to insufficient cooling?

The problems such as "burn" bluing in grinding are caused by local high temperature overheating.

The cooling effect of grinding fluid is to transfer the accumulated heat on the grinding wheel and 

workpiece in time through the heat transfer effect of solid and liquid two phases, 

so as to keep it at a lower temperature level, 

so as to ensure the dimensional accuracy of the workpiece and facilitate the disassembly operation.

The lower temperature level of the grinding wheel and the workpiece is of course effective in reducing the grinding zone temperature. 

But this cooling is indirect, the more direct way is to improve the lubrication conditions of the grinding area, 

reduce the heat generated by the friction point, 

which is more effective to reduce the instantaneous high temperature of the friction point.

Therefore, if the burn problem occurs, it should be solved mainly by improving the lubrication of grinding fluid. 

For example, change the water base to oil base or improve the extreme pressure activity of grinding fluid.