Research On Hot-Warm-Cold-rolling Process Model Of Cast-rolling High Silicon Steel Strip

Silicon steel is an important soft magnetic material.It is widely applied in electric power and electronic communication industry.Compared with ordinary silicon steel,high silicon steel has excellent soft magnetic properties and high frequency characteristics,such as high permeability,high resistivity,near zero magnetostriction coefficient and low iron loss,which is very beneficial to reduce transformer noise,achieve ultra miniaturization of electric appliance and less energy consumption.However,low temperature can result in the solid solution strengthening and the internal formation of an orderly structure of high silicon steel,which cause the increases of deformation resistance.It is difficult to make production by conventional rolling process.State Key Laboratory of Rolling and Automation of Northeastern University had made a lot of research on the production of 6.5wt%Si high silicon steel using thin strip casting and rolling technology,and had a series of achievements.Based on the above research on high silicon steel,State Key Laboratory of Rolling and Automation of Northeastern University has built a production line of casting strip-hot rolling-warm rolling-cold rolling to explore the rolling process of high silicon steel.This paper focus on the research of rolling process model of hot rolling-warm rolling-cold rolling process of casting high silicon steel strip.The main contents of this paper are as follows:(1)The strip rolling process of high silicon steel was explored through hot rolling,warm rolling and cold rolling test,and the strip of 6.5wt%Si steel was rolled to less than 0.2mm successfully.The reasonable rolling process is as follow:the levelling rolling temperature is 1160℃,which reduction rate is 5%-10%every pass;hot rolling temperature is 850℃,which reduction rate is 10%every pass and multi-pass target thickness is 1mm;warm rolling temperature is 750℃,which reduction rate is 4%every pass and multi-pass target thickness is 0.5mm.And during cold rolling,the warm roll and reversing rolling with same roll gap,the reduction rate of every pass is about 2%.(2)Based on the basic theory of rolling process model,the deformation resistance model of hot rolling,warm rolling and cold rolling were obtained by inverse calculation with measured data;the friction coefficient of warm rolling and cold rolling is researched;finally,the rolling process model is used to calculate the predicted rolling force which is compared with the measured value to check and correct the accuracy of the model.(3)The calculation program for hot rolling,warm rolling and cold rolling process of casting high silicon steel strip was developed with VS2008,the program can achieve the functions of inverse calculation of deformation resistance,calculation of friction coefficient and calculation of rolling force.(4)The calculation results of the program were analyzed.The model of the deformation resistance obtained from the measured data is fit well with the inverse value,and the error between predicted rolling force calculated by the 6.5wt%Si steel strip rolling process model established in this paper and measured value is within ±5%,and the precision is good.