Study on Quenching Process of 960 MPa Quenched and Tempered Steel Plates for Construction Machinery

To develop the Q960 high-strength quenched and tempered steel plates,the effects of quenching treating regime on the microstructure and mechanical properties of plate specimens were investigated.The results showed that the dissolution and distribution of alloying elements and the original austenite grain size are determined by quenching temperature and holding time and,finally,the overall mechanical properties are obviously affected by the quenching process parameters,and the excellent overall properties of specimens can be obtained when the quenching temperature is 900 ℃ with holding time 15~25 min,i.e.,the yield strength is 1 110 MPa,tensile strength 1 140 MPa and percentage elongation 14% with the Charpy impact energy 130 J at-40 ℃.All these indexes come up to the national standard GB/T16270—2009.