Study On Structure And Capabilities Of Nickel-Base Deposit Alloy In Inverter Controlled Longitudinal Magnetic Field

Following the rapid development of technology and continued increasing of the degree of mechanization and automation, people pay more attention to hazard of parts wearing and corrosion. Thus, decreasing grinding abrasion and increasing mechanical wearing has great economic significance. This paper is about the effect of introduced longitudinal square wave magnetic, which is produced by inverter on plasma overlaying welding alloy, on improving the structure and capabilities of surfacing deposit. Electromagnetic applied to welding is a new welding technology, which has been widely used in many kinds of fields in recent years. The common exoteric magnetic field is longitudinal, which parallels with arc axial. The longitudinal magnetic field promotes arc to revolute, changes plasma jet of arc column and radial distribution of density of arc, effects the heating and melting of base metal and formation of weld. Experiments show that the introduced magnetic field can give a remarkable effective intervention to the transition of droplet, flowing of molten bath metal, crystalline and nucleation of molten bath and the process of crystalline growth. The magnetic field promotes the refining degree of primary crystallization structure, decreases the chemistry non-homogeneity, improves plasticity and toughness of surfacing deposit, and decreases the sensibility of crystal crack and gas cavity. Therefore it can improve quality of surfacing deposit.During the test, the surfacing deposit effects of magnetic field current and magnetic field frequency on hardness, wearing, and microstructure were studied and the properties of surfacing deposit of introduced magnetic field were compared with that without introduced magnetic field. The main results are as follows: (1)Magnetic current and weld criterion parameters must be matched properly, in order to obtain the optimal effect of grain refining by means of theoretical analysis. 2)The tests of hardness , wearing and microstructures show that the magnetic fieldprimary structure and secondary structure can be refined;The magnetic field current and magnetic field frequency stirring can effect nucleate ratio and refine structure effective.