We report on an order-reversed quenching phenomenon in manganese nitrides under flash melting,which prevents the thermodynamically favorable phase transformations from occurring at high temperatures by providing a narrow window of time.The Mn-N kept un-decomposed at high temperatures generated by current up to 339 MA/m2 within 60 ms.After flash melting,the Mn-N shows a significantly enhanced coercivity and a decreased crystalline size.The Mn-N samples decompose rapidly at temperatures above 1100K with time.The order reversed quenching technique is potentially useful in processing and preventing phase transformations of meta stable materials at high temperatures.