Improved ferritic square steel roughing roll and preparation method thereof

Abstract

The invention discloses an improved ferritic square steel roughing roll and a preparation method thereof. Two rolls symmetrically distributed up and down are provided, the rolls are provided with rollmain bodies made of a ferrite alloy, a plurality of rectangular roughing circular grooves are uniformly formed in the roll main bodies along a length direction, the two ends of the roll main bodies are respectively provided with bearing installation parts made of the ferrite alloy, a connecting part made of the ferrite alloy is arranged outside the bearing installation part at one side, and a transmission part made of the ferrite alloy is arranged outside the bearing installation part at the other side; the roughing roll comprises, by weight, 3.2-3.4% of carbon, 2-2.1% of silicon, 0 .5%-0.7%of manganese, 0.2-0.4% of chromium, 0.3-0.5% of molybdenum, 1.4-1.6% of nickel, 0.1-0.3% of niobium and 0 .05-0.15% of vanadium. The tensile strength, wear resistance, thermal crack resistance, impacttoughness and uniform hardness of the roll prepared by the method are improved and enhanced.

Description

technical field [0001] The invention relates to the technical field of rolls, in particular to an improved ferritic square steel rough roll and a preparation method thereof. Background technique [0002] Due to the simple shape of the square steel, the shape of the pass does not change much during rolling, but because the dimensions of the four sides are the same, there are special requirements for the rolls used, especially the rough rolls used by the previous unit. The wear of the type must be basically the same to ensure that the specifications and sizes of the finished square steel meet the requirements. At present, some manufacturers use pearlitic nodular cast iron and alloy semi-steel for the rolls used in the rough rolling mills for rolling square steel. The former is often due to the problem of large hardness drop. After a certain amount of rolling, oblique directional wear indentations appear on the side wall of the pass and the bottom of the pass groove. As the in...

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Problems solved by technology

The former is often due to the problem of large hardness drop. After a certain amount of rolling, oblique directional wear indentations appear on the side wall of the pass and the bottom of the pass groove. As the indentation increases, it will directly affect the surface quality of the finished square steel. The main reason is that when the indentation reaches a certain depth, it will cause fine patchy scales in the subsequent rolling of the rolled piece, resulting in fine concave-convex spot grooves on the surface of the square steel after pickling, causing the surface of the square steel to be dull, and the alloy semi-steel Due to the existence of a small amount of irregular flake and network carbides in the roll, under the influence of factors such as hot extrusion of the high-temperature rolled piece and cooling water circulation during the rolling operation, the roll body hole After accelerated oxidation, fatigue thermal cracks are generated in the matrix structure of the type, and then extended, which promotes the premature failure of the hole type, thereby affecting the working efficiency

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