Research On The Technology Of Magnesium Oxide Coating For Grain-Oriented Silicon Steel

This paper takes the first domestic grain-oriented silicon steel continuous annealing and coating experimental unit project which was developed by RAL for a steel mill as the researching background.The selection of Magnesium Oxide used for grain-oriented silicon steel coating was studied and analyzed,the MgO coating system for grain-oriented silicon steel was developed,and the coating technology based on this coating system was studied.The main content of this paper includes:1.The selection method of Magnesium Oxide used for grain-oriented silicon steel was presented according to the characteristics of MgO and the coating mechanism.In this paper,the test method of MgO used for grain-oriented silicon steel was presented by analyzing the action mechanism of MgO coating layer during the producing process of grain-oriented silicon steel.The selection basis of MgO used for grain-oriented silicon steel was presented according to the differences about the detection of the characteristics and the micro morphology of MgO.2.The grain-oriented silicon steel Magnesium Oxide coating system was developed.The influence factors about the MgO coating thickness were analyzed,and taking this as the design principle,the coating system which composes of coating machine,drying and curing oven and coiling machine was built,the prediction and control of the coating thickness based on the soft measurement method were established.3.The Magnesium Oxide coating technology of grain-oriented silicon steel was studied.The influence of the surface cleaning condition before annealing,and the formation of the oxide layer during annealing on the bottom layer were analyzed.By way of the experimental studies,the coating configuration,the selection of additives,the drying and curing temperature,the coiling tension distribution etc.were confirmed.4.The Magnesium Oxide coating technology for the grain-oriented silicon steel was applied and examined.The coating effects of the MgO coating layer and the magnesium silicate layer which was formed after high temperature annealing were examined respectively.The comparison of Mg2SiO4 layer formed under different coating amount was researched,and the research results show that using appropriate MgO coating amount can not only improve the surface condition of the grain-oriented silicon steel,but is also conducive to the improvement of magnetic sense and the reduction the iron loss of the final products.