Mechanical Properties Of Iron Based Surfacing Alloys Applied DC Transverse Magnetic Field

With the rapid development of industry technology and continuous increase of the degree of mechanization and automation, people pay more attention to hazard of parts wearing. In all the abrasion types, the grinding abrasion takes the greatest percent. It has a great economic significance to decrease grinding abrasion and increase mechanical wearing.Electromagnetic is applied to welding as a new welding technology in recent years. The introduced magnetic field can give an 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, So it can strengthen hardness and wearing resistance of weld metal overlay and improve quality of surfacing deposit.The carbon rod is used as electrode bar to melt alloy powder in the building-up welding experiment with applied DC transverse magnetic field. The effect of surfacing processing parameter and magnetic field parameter on overlay's mechanical properties is studied through analyzing the average degree of hardness, the weightlessness of deposited metal and the microstructure. The mechanism for overlay during solidification and the shape and distribution of hard phase by applied longitudinal magnetic field has been discussed intentionally. The paper also makes theoretical analysis and preliminary discussion on the wear-resisting mechanism of the overlay.Following are the main results:1 The surfacing deposit with introduced transverse magnetic field has higher hardness and better wearing resistance. The optimum parameters can greatly influence grain structure refinement. 2 The hard phase in weld metal overlay is distributed randomly without magnetic field; it is fine and distributed "the hexagon" in optimum parameters, then hardness and wear extent in weld metal overlay are higher.3 The result indicated: the properties of surfacing deposit are optimal when surfacing current is 180A, surfacing speed is 12cm/min, magnetic field current is 3A, hardness in weld metal overlay is HRC54.4, wearing capacityâ–³G=0.0335g.