Yan Qiangjun,Chen Gang,Ruan Hao,et al.Effect of Online and Offline Quenching on Microstructure and Properties of Q1300E Ultra-High Strength Structural Steel Plate[J].Special Steel,
Yan Qiangjun,Chen Gang,Ruan Hao,et al.Effect of Online and Offline Quenching on Microstructure and Properties of Q1300E Ultra-High Strength Structural Steel Plate[J].Special Steel,DOI:.
Effect of Online and Offline Quenching on Microstructure and Properties of Q1300E Ultra-High Strength Structural Steel Plate
Ultra-high strength structural steel is widely used in heavy equipment fields, and the synergistic matching of its strength and low-temperature toughness is a research focus. The conventional offline quenching and tempering (RQ-T) process has issues such as long processing cycles and microstructural coarsening. In this study, the direct quenching and tempering (DQ-T) process was adopted to synergistically improve strength and toughness through microstructural refinement. The microstructure and fine structure of Q1300E steel plates subjected to DQ-T and RQ-T processes were comparatively investigated by optical microscopy (OM), transmission electron microscopy (TEM), and electron backscatter diffraction (EBSD). Room-temperature tensile tests and Charpy impact tests at -40 °C were also conducted. The results show that the direct quenching and tempering at 190 °C process exhibits the best performance, with a yield strength reaching 1 435 MPa and an impact energy of 52.5 J at -40 °C. Compared with the RQ-T process, the DQ-T process refines the lath substructure, increases the dislocation density, enhances hardenability, and simultaneously obtains more retained austenite, which effectively improves low-temperature toughness, thereby synergistically enhancing both strength and impact energy at -40 °C.
关键词
Keywords
references
Duan X H , Cao X , Wang Y X , et al . Making low alloy ultrahigh strength steel tough by high-density NiAl clusters [J]. Materials Characterization , 2025 , 229 : 115480 .
Wang C H , Chen R , Wang C Y , et al . Strong and ductile low carbon low alloy steels with multiphase bimodal microstructure [J]. International Journal of Plasticity , 2024 , 181 : 104097 .
Geng H Y , Sun X Y , Zhao Y J , et al . Assessing the microstructure, mechanical properties, and deformation mechanism of high-strength low-alloy steel prepared via powder metallurgy [J]. Journal of Materials Research and Technology , 2025 , 35 : 3620 - 3633 .
Morito S , Yoshida H , Maki T , et al . Effect of block size on the strength of lath martensite in low carbon steels [J]. Materials Science and Engineering: A , 2006 , 438 : 237 - 240 .
Zeng Y P , Zhu P Y , Tong K . Effect of microstructure on the low temperature toughness of high strength pipeline steels [J]. International Journal of Minerals,Metallurgy,and Materials , 2015 , 22 ( 3 ): 254 - 261 .