Manufacturing method of double-metal composite chilled cast-iron roll

Abstract

The invention discloses a manufacturing method of a double-metal composite chilled cast-iron roll. The manufacturing method comprises the following procedures of: smelting an outer-layer chilled cast-iron wear-resistant material and an inner-layer support ash-iron material, centrifugally casting a mold for preparation, centrifugally casting, cooling and demolding for taking a product; a matrix organization structure of the outer-layer chilled cast-iron wear-resistant material is as follows: the content of carbide is 40-50%, the content of pearlite is 40-50%, and the content of ledeburite is 0-20%; and the cooling speed in centrifugal casting is as follows: the cooling speed at an interval with the temperature drop from 1350 DEG C to 1180 DEG C is controlled to be higher than 80 DEG C / min,the cooling speed at an interval with the temperature drop from 1180 DEG C to 720 DEG C is 20-25 DEG C / min, and the cooling speed at an interval with the temperature drop from 720 DEG C to normal temperature is controlled to be lower than 30 DEG C / min. The manufacturing method disclosed by the invention has the advantages that for the outer-layer material of the roll manufactured by utilizing themethod, the crystalline grain is thinner and uniform, the hardness change of a roll body is smaller along the radial direction and the axial direction; and the tensile strength is strong, the wear resistance is good and the service life is long.

Description

technical field [0001] The invention relates to the field of manufacturing methods of rolls in food machinery, in particular to a manufacturing method of bimetallic composite chilled cast iron rolls. Background technique [0002] In the field of food machinery processing, there is a bimetallic composite chilled cast iron roll, such as a flour roll, which is usually made of two layers of metal and is a long cylindrical shape, which requires the hardness of the roll surface along the radial direction and along the axial direction. Both are very high. [0003] The existing manufacturing method of the bimetallic composite chilled cast iron roll usually includes the steps of smelting the wear-resistant chilled cast iron material of the outer layer and the supporting gray cast iron material of the inner layer, preparation of the centrifugal casting mold, centrifugal casting, cooling, and demoulding and taking parts. Among them, the matrix structure requirements of the outer chill...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for manufacturing bimetallic composite chilled cast iron rolls, so as to overcome the problem that the hardness of the rolls fluctuates and varies greatly when manufacturing chilled cast iron rolls using the prior art manufacturing method mentioned in the background technology, thereby causing the roll Insufficient tensile strength, poor wear resistance and short service life

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