Microstructure and Property Uniformity of 07MnNiMoDR Low Carbon Bainitic Steel Plate

Impact toughness stability has always been an important issue in the production of low carbon bainitic steelLow carbon bainitic steel plate. In this paper, the microstructureMicrostructure uniformity of 07MnNiMoDR low carbon bainitic steelLow carbon bainitic steel plate in the width and thickness directions was studied. The results show that the grain size near the surface in the thickness direction of the steel plate is smaller and the hardness is lower; the grain size at the center thickness is larger, and the hardness is higher due to the segregationSegregation of carbon. In addition to the structure and hardness, there are also large fluctuations in the chemical composition along the width direction. The segregationSegregation elements at 1/2 of the thickness of the tempered steel plate are mainly carbon, sulfur, manganese, niobium, etc. They exist in the form of MnS and NbC compounds, which significantly increases the probability of intergranular fracture during the impact process.