Investigation On Mechanical Properties And Magnetic Properties Of 4.5wt.%Si Non-oriented Electrical Steel

Since the 18th CPC National Congress,President Xi has proposed:"Green water and green mountains are golden mountains and silver mountains",so that when we are satisfied with enriching material and cultural life,we should pay more attention to environmental protection issues.This year,NPC&CPPCC also proposed the concept of“carbon peaking”and“carbon neutral”,which aims to achieve sustainable development by controlling carbon emissions.As an important soft magnetic alloy,electrical steel has good magnetic properties and is mostly used in iron core rotor materials and engine materials for new energy electric cars.Compared with ordinary steel plates,the preparation process of non-oriented electrical steel is more complicated and the requirements are stricter.As far as the current technology for preparing non-oriented electrical steel sheets is concerned,in addition to the conventional applications in production,the twin-roll thin strip continuous casting and rolling technology has attracted more attention.The conventional process for manufacturing non-oriented electrical steel is mature,but the process is complicated;while the twin-roll thin strip continuous casting process has a short production cycle and is more environmentally friendly,but it will cause cracks on the surface of the steel plate during the production process.This paper uses two methods to prepare 4.5wt.%Si non-oriented electrical steel using traditional technology and double-roll thin strip continuous casting technology.For hot-rolled plates,warm-rolled plates prepared by traditional processes,and electrical steel prepared by double-roll thin strip continuous casting technology The thin strip is used for the detection and analysis of microstructure,texture,mechanical properties and magnetic properties.The main research contents of this paper are as follows:(1)The heat treatment process parameters of the 4.5wt.%Si non-oriented electrical steel manufactured by conventional processes were changed,and the changes in the mechanical properties of the 4.5wt.%Si non-oriented electrical steel at different annealing temperatures and times were studied.The fracture mode of hot-rolled 4.5wt.%Si non-oriented annealed steel sheet at room temperature is brittle fracture and has a low Vickers hardness.The hot-rolled steel sheet is annealed at 900^oC and recrystallized,and has the highest elongation of 8.7%.When the annealing temperature of the 4.5wt.%Si non-oriented electrical steel hot-rolled steel sheet manufactured by the traditional rolling process is 900^oC,there are{011}<211>,{012}<610>,{021}<501>,{110}<113>and other textures.When the annealing temperature was 1000^oC and 1100^oC,the overall texture is enhanced,and there is a{110}<001>texture that is unfavorable to the plastic strain ratio of the steel sheet.(2)The microstructure,room temperature mechanical properties and magnetic properties of warm-rolled steel sheets with different warm rolling temperatures and different annealing times were studied.The warm-rolled steel sheets all begin to return to recrystallization behavior within 21s.The steel plate that has been warm-rolled at 500^oC has the fastest recrystallization rate.The maximum tensile strength is 803.9MPa and the maximum elongation can reach 24.49%.The saturation magnetic induction intensity of the warm-rolled steel sheet decreases with the extension of the annealing time,and its maximum saturation magnetic induction intensity is 1.86T.(3)The microstructure changes of the twin-roll strip casting strips under the same annealing temperature and different annealing time were studied,and the mechanical properties of the annealed strip at room temperature and 100^oC-200^oC were tested and analyzed.The experimental results showed that the steel sheet recrystallizes during the annealing process.After 60s annealing,the uniform elongation and elongation at break reached the maximum at room temperature,which were 16.2%and 16.5%,respectively.The Vickers hardness of the steel sheet decreases first and then rises with the extension of the annealing time.At a stretching temperature of 100^oC-200^oC,the steel sheet exhibits a good elongation,but the strength is slightly reduced.When the annealing time is 12s and the stretching temperature is 100^oC,the steel plate has a maximum ultimate tensile strength of 526.7MPa.When the annealing time was 3min and the stretching temperature was200^oC,the elongation of the steel plate reached the maximum value of 19.2%.(4)The magnetic properties of twin-roll strip casting strips with annealing time of60s and 3min were studied.It was found that the magnetic properties of the steel sheet at an annealing time of 3min were better,and the magnetic properties were 1.689T(B₅₀),2.951W/kg(P_15/50),23.58W/kg(P_10/400),22.5W/kg(P_5/1000).