Transformation Behavior of Austenite of EH36 Ship Plate Steel during Continuous Cooling

Using Gleeble 2000 thermal-mechanical simulator, the phase transformation behavior of EH36 ship steels was studied after cooling with constant, increasing and decreasing rate, respectively.Results show that the ultimate microstructure is mainly bainite when the cooling rate is 4-16 ℃/s and the temperature is located in the range of 400-650 ℃ during continuous cooling,the proportion of bainite is increasing along with increment of cooling rate;After cooling to 600 ℃ with 1 ℃/s or higher constant rate at first stage and then with the rate of half the initial value,the final microstructure is similar to that achieved after cooling with the second stage rate constantly.Furthermore,if the cooling rate at the second stage is double the initial rate,the microstructure also accord with that achieved after cooling just with the second stage rate.