| Abstract Scope |
Effects of the morphology, size and distribution of precipitated phase and microstructure on the mechanical properties of 1000MPa ultra-high strength steel was investigated by the transmission electron microscopy (TEM) through the heat treatment process of quenching and tempering. The design idea of adding copper and reducing carbon was significantly used to improve the strength and toughness matching and welding performance of 1000MPa ultra-high strength steel. Its strength and toughness mechanism were that a large number of nano ε-Cu were formed in steel to play the role of precipitation strengthening after the aging treatment of copper-bearing steel, in order to compensate for the strength loss caused by carbon reduction, so as to greatly improve the strength and weldability of steel. The reversed austenite was formed in 1000 MPa ultra-high strength steel which were strengthened by dislocation substructure and precipitated phase after tempering at high temperature, it was distributed at large Angle grain boundary, this was one of the important reasons for improving the low temperature impact toughness of the sample. |