Numerical Simulation Of Induction Cladding Coating On 27SiMn Steel For Hydraulic Support Column

Mine hydraulic support column plays a supporting role in the mine.Due to the bad underground environment,the surface of the hydraulic support column is easy to wear,corrosion,scratch,etc.leading to the sealing failure and leakage of the surface of the column,so that the whole hydraulic support failure.Induction cladding coating refers to the use of induction heating to melt the coating,so that the coating and the substrate metallurgical bonding,has the advantages of high efficiency,fast to obtain a large area of cladding coating.However,it is difficult to control the properties of coatings in practical application,and the distribution of temperature field and stress field of coatings is not well understood.In order to grasp the distribution of temperature field and stress field in time and space in the process of induction cladding,according to the principle of induction heating,Maxwell and ANSYS Workbench software were used to simulate the magneto-thermal coupling field of work piece in the process of induction heating,and the temperature field distribution of coating and substrate was obtained.On this basis,with temperature as the applied load,the thermal stress coupling simulation was carried out by using ANSYS Workbench to study the distribution of stress field after melting and cooling.In this paper,the 27 Si Mn steel commonly used in hydraulic support column is used as the matrix,and the iron-based self-melting alloy powder is used as the coating.Three kinds of current intensifies of 500 A,600A and 700 A and three kinds of current frequencies of 100 kHz,150 kHz and 200 kHz are used for simulation calculation.The optimal cladding parameters are obtained through orthogonal experiment design.The main conclusions are as follows:Simulation results of electromagnetic field show that the current density in the magnetic field is proportional to the current intensity and current frequency.When the current intensity is 700 A and the current frequency is 200 kHz,the current density on the coating surface reaches 250A/mm2,which is nearly twice that of 500 A and100kHz.Skin depth is inversely proportional to frequency,high current frequency and high current intensity increase the current density on the surface of the coating,and make its surface temperature higher.On the contrary,the lower the frequency,the smaller the current intensity,the smaller the current density,the larger the distribution range,the lower the surface current density,the lower the heating efficiency,the longer the heating time,and the greater the impact on the matrix.The results of electromagnetic-thermal coupling simulation show that,under the same current intensity,the higher the frequency,the greater the current density on the coating surface,the higher the coating surface temperature,and the closer the high temperature distribution to the coating region.At the same frequency,the higher the current intensity,the greater the current density,the faster the coating heating rate,and the smaller the impact on the substrate heat.By comparing the simulation results,the best cladding process parameters were selected: current intensity of 600 A,frequency of 200 kHz,heating time of about 2s.The results of thermal-stress coupling simulation show that slow cooling in asbestos ash can produce lower residual stress than air cooling,which makes the molten coating effect better and superior.