Research On The Damage Of Electrical Steel Surface Insulation Coating During The Cutting Process

Electrical insulation coating on either side of the steel matrix and constitutes the three layers of structure of composite material,in the process of cutting and processing,electrical steel surface insulation coating on the edge of the incision of hard brittle damage broken dust formation,not only destroy the silicon steel sheet cut edge the integrity of the insulation layer,affect the electric insulation performance and electromagnetic performance of the steel,also cause pollution to the production environment.It is of great significance to deeply study the damage of surface insulation coating in the process of electrical steel cutting.Based on electrical steel oblique shear and disc cutting two kinds of cutting processing of disc shear experiment,combining with the three point bending test and tensile test results,through the DEFORM-2D finite element simulation,studied the electrical steel of different thickness and orientation in the process of shearing surface insulation coating damage morphology,breakage width and the law of the processing parameters,delamination failure behavior,damage mechanism and process control method.According to the experiment of the oblique cutting and cutting of 0.23 mm oriented silicon steel plate,it is found that the damaged area of electrical steel surface is divided into crack zone,flaking area and crushing zone.Shearing silicon steel surface insulation materials form clastic in the manufacturing process,it is mainly due to the peeling area insulation coating spalling and composite with T2 coating layer and C2,the size ranges from micron to over 100 microns.With the ratio of tool side gap and plate thickn ess increased,the width of the peeling area remained stable,but the width of the crack zone increased,and the width of crushing zone remained constant.The shear rate can reach a minimum of 100 microns in the range of 0.1~0.3m/s,and the width of the da mage area will increase with the increase of shear speed or decrease.By the DEFORM-2D finite element simulation and cutting processing,found that the shear process,the breakage of coating is closely related to the substrate material forced deformation,close to the cutting tool edge 10?m~20?m area of the material by the tensile deformation first,with the tool cutting into compression deformation.The material that is far from the cutting edge of the tool is stretched deformation,and the peeling of the coating is first produced in the vicinity of the cutting edge and about 50?m from the cutter,then it expands to both sides with the cutting of the tool.By the three-point bending test and tensile test,the formation,found that when plate under compressive stress,coating inside crack expanding along with the direction of the panel with a certain Angle,new crack parallel to the plate and coating and substrate interface have large cracks,when these cracks rendezvous disbonding;When under tensile stress,coating inside tiny cracks extend along the vertical direction of the plate to the coating and substrate interface,and then along the interface extension until after contact with the other crack,flake coating.When the tensile strain reached 11%,the surface of the electrical steel began to flake off.When the tensile strain reached 12%,the surface of the electrician steel appeared to flake off.Through the study of the disc of electrical steel plates of different thickness she ar slitting cutting processing,the results showed that the surface insulation coating was badly damaged after the shearing process of the thin grain-oriented silicon steel,the crack area and small spalling area were on the side of the collapse angle,and a large area of spalling appeared on the burr side.The insulation coating of the thick non-oriented silicon steel surface is less damaged,the cracks and flaking occur in the local area,and the burr side is damaged in about 50?m.The 0.3mm grain-oriented silicon steel insulating coating damage width of the collapse angle side and the burr side is decreased with the increase of the radial clearance of the disc knife.With the increase of the lateral clearance,the damage width of the insulation coating on the side surface of the c ollapse Angle gradually increases,and the damage of the insulation coating on the burr side surface gradually decreases.