| Grain-Oriented silicon steel is the major material of the iron-core of transformer. The Grain-Oriented silicon steel produced by traditional process of heating steel slab has many shortcomings. While using CSP process to produce high magnetic induction Grain-Oriented silicon steel (Hi-B steel) could reduce costs and improve product quality. This article simulates CSP process to produce Hi-B steel and uses optical microscope and transmission electron microscope to investigate the microstructures and precipitates of the samples under different conditions of hot-rolling, normalizing, cold-rolling, decarburizing annealing, nitriding treatment and high-temperature annealing, then analyses the evolution rules of the inhibitor during the procedure of producing Hi-B steel. Some conclusions have been drawn as follows:(1) There are organization gradient, texture gradient and inhibitor gradient along the thickness direction in hot-rolled slab. From the surface to the center, the amount of the inhibitor increases and the size of which decreases. The types of the inhibitor are mainly A1N and MnS. After normalization, the crystal grain grows up, the organization of which becomes more homogeneous, the gradient of inhibitor basically remains unchanged, the amount of A1N increases and MnS stays unchanged.(2) The amount and the size of inhibitor doesn’t change obviously after cold-rolling and decarburizing annealing, but the amount of A1N increases greatly after nitriding treatment.(3) During the procedure of high-temperature annealing, with the temprature increases, the size of crystal grain increases, the amount of inhibitor decreases and the size of which increases. At the end of high-temperature annealing, the inhibitor of smaller size dissolves and that of greater size grows up. The pinning force of the inhibitor weakens, which reduces the ability of hindering the crystal grain from growing up and some crystal grain grows up abnormally. |
PDF Full Text Request