A manufacturing method of graphite-containing high-speed steel combined nesting composite roll

Abstract

The invention discloses a manufacturing method for a graphite-containing high-speed steel composite inlaid composite roll, and belongs to the technical field of mechanical casting. Chemical elements of B and N are introduced into a conventional high-speed steel component; MC type and / or M2C type, dotted and / or massive high-hardness alloy carbide, nitride and boride with area total percentage being 20-35% are diffused and distributed in a matrix structure of a working layer; the carbide, the nitride and the boride are firstly deteriorated, and then, graphite inoculation and modification treatment is carried out, so that graphite is separated out in the original structure, the problem of a large friction coefficient of the original conventional high-speed steel roll is further solved while the high-speed steel roll keeps specific high temperature and wear resistance advantage of the conventional high-speed steel, wear resistance of the high-speed steel is sufficiently brought into play to achieve lubricating effect between the roll and a workpiece during rolling, and thus, occurrence of a steel sticking phenomenon is prevented; and moreover, by virtue of heat conduction and lubricating property of the graphite, the defects that the high-speed steel roll is sensitive to thermal stock and heat cracks, is liable to stick steel, and is liable to have surface roughening can be improved, so that especially while the roll is used on a finished product rack, surface brightness of rolled stock is remarkably improved.

Description

technical field [0001] The invention relates to a method for manufacturing a graphite-containing high-speed steel compound-inserted composite roll, which belongs to the technical field of mechanical casting. Background technique [0002] The alloy content of the outer layer (working layer) of the existing traditional high-speed steel roll is usually C 1.5-2.5, Si 0.2-0.8, Mn 0.4-0.8, P≤0.05, S≤0.02, Cr 4-6, Ni 0.6- 1.5, Mo 3-5, W 0-3, the metallographic structure of the outer layer does not contain graphite, and these alloy elements mainly exist in the form of carbides in the roll structure, and the proportion of carbides is usually 10-20% between. The proportion of granular alloy carbides is relatively low, and the proportion of matrix area is relatively large. Therefore, during the use of the roll, especially when it is used for the finish rolling product stand, the rolling temperature is low, and the rolling speed is high, the roll base is exposed to the rolling materia...

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Problems solved by technology

Therefore, during the use of the roll, especially when it is used for the finish rolling product stand, the rolling temperature is low, and the rolling speed is high, the roll base is exposed to the rolling material passing through at low temperature and high speed and the entrainment on the surface of the rolling material. Under the friction of oxide scales, the matrix is ​​preferentially worn and the fulcrum of high-hard carbide is exposed on the surface of the roll, which is specifically manifested in the increase of the surface friction coefficient of the roll (pass type), the decrease of brightness (the phenomenon of roughening), and in severe cases There is steel sticking on the pass surface, which affects the surface quality of rolled products

As a result, the unique anti-wear performance of high-speed steel and the ability to maintain roll shape cannot be effectively exerted, resulting in early roll change

[0003] In addition, when the existing traditional high-speed steel rolls are used in the process of preparing the finished round bar frame with large specifications and high surface quality requirements, due to the deep pass, the inner groove bottom and the groove side of the roll pass The linear velocity difference in different radial directions leads to the relative solid slip (rheology) of the rolled material at the same section, and the huge solid slip produces a file force on the surface of the roll pass, resulting in slippage between the bottom and the side wall of the roll pass. The wrinkle texture is shifted, and the wear of the bottom of the groove is intensified, which affects the precision and surface quality of the rolled material, and cannot fully exert the wear-resistant characteristics of high-speed steel, resulting in early roll change

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