Effect of Controlled Rolling and Controlled Cooling Processes on Microstructure and Properties of Low Alloyed Ultra-high Strength Steel for Engineering Machinery

The microstructure and properties of the low alloyed ultra-high strength steel for engineering machinery under different controlled rolling and controlled cooling processes were investigated by the laboratory simulation rolling.The results show that: the ultra-high strength steel has the best strength and toughness by two stages of controlled rolling,direct quenching and low temperature tempering technology,and its tensile strength,yield strength,elongation and reduction of area are 1902MPa,1568MPa,10% and 43%,respectively;the impact energy of room temperature and-40℃ are 28J and 24J,respectively,and hardness value is 53HRC.