Design Of The Organism Of The Super-hardness Piled Metal For Better Toughness

Based on repairing the cold working roll in the field of metallurgy, this article is to develop a kind of material with super hardness and better toughness. Due to the strict demand for the super hardness over 60 HRC and crack resistance for the cold mill working roll ,the piled material must be provided with not only super hardness but also crack resistance and better toughness .Based on the formerly research about the optimization for the piled material ,this article will discuss how to increase the toughness of the piled metal on the condition of having super hardness through electromagnetism stirring and .modification.On the welding technology aspect, in order to increase the toughness , the article discuses the effect of the Lorentz force which will stir the weld molten pool. This kind of electromagnetism-stirring can refine the crystal grain and make the carbide net broken, decrease the size of the trapped oxide and improve the homogeneous of the chemical component; so that the toughness will be increased, the toughness has been increased 27.7%. On the weld metallurgy aspect, after the optimization of the basic alloy system including C, Cr, Mo, W, V, some modificators such as Ti,Nb,Ta are added into the welding wire. Through modification the size of the grain will decrease ;the shape and distribution of the carbide will be changed; so that the toughness can be improved .