Effects of Quenching Process on the Microstructure and Mechanical Properties of Ultra-high Strength Offshore Engineering Steel FH790
The effects of different quenching processes on the microstructure and mechanical properties of ultra-high strength offshore engineering steel FH790 are studied and analyzed by means of scanning electron microscope,transmission electron microscope and mechanical testing equipment.The results show that for the test steel,as the quenching temperature increases,the grain size of the prior austenite increases,the microstructure coarsens significant-ly,the effective grain size becomes larger,the tensile strength presents the tendency of gradual increase,but the impact toughness deteriorates obviously.After water cooling at the quenching temperature of 850℃ and tempering with appro-priate process,the test steel obtains proper strength,good impact toughness and martensite.