There is a minimum time gap between quenching and tempering of steel.It differs from steel to steel. For eg. if it is a plain carbon steel, this thing may not call for urgent attention but if is an alloy steel, then this thing becomes a cause of concern as it can cause microcracks to grow and form macrocracks if the time interval b/w quenching and tempering is high. Are you guys having any data which states that what should be the minimum time interval for different steels.Any help will be appreciated.