Nodular cast iron and centrifugal composite casting roller

Abstract

The invention relates to nodular cast iron and a centrifugal composite casting roller. The nodular cast iron comprises, by weight, 3.0-3.4% of C, 2.2-2.4% of Si, Mn being less than 0.4, P being less than 0.05, S being less than 0.015, 0.85-0.95% of Ni, 0.3-0.5% of Cu, 0.2-0.3% of Mo, 0.015-0.020% of Sb, 0.01-0.03% of RE, 0.03-0.06% of Mg, and the balance being Fe and impurity elements. Concrete steps comprise: firstly melting base iron, using a cerium-based light RE-Mg nodulizer and an Mg-Ni alloy nodulizer for spheroidising by pouring process; using a long-acting inoculant containing barium and calcium elements for stream inoculation during the casting process while the casting temperature of nodular cast iron is 1430-1450 DEG C, and realizing metallurgy melting with centrifugal casting high chromium cast steel to form a roll core part and a roll neck. According to the obtained roll neck, the nodular cast iron tensile strength is greater than or equal to 550MPa, graphite nodularity reaches 2-3 level, hardness number is HSD35-45, and there is no macroscopic grey spots and bright spots. In addition, the invention also provides the high chromium cast steel centrifugal composite casting roller with the above nodular cast iron as the core part.

Description

technical field [0001] The present invention is an improvement on thick and large-section ductile iron, and is different from the low-temperature spheroidizing treatment and low-temperature casting required by the traditional thick and large-section ductile iron manufacturing technology. High-temperature spheroidizing treatment, high-temperature casting, through alloying, treatment with two spheroidizing agents, adding trace elements to prevent graphite distortion and other technical measures, make ductile iron suitable for manufacturing high-chromium cast steel centrifugal composite casting roll core and roll neck , to meet the technical requirements for the strength and hardness of the rolls in the roughing stand of the hot tandem mill. Background technique [0002] The rough rolling stand of the hot continuous rolling mill is generally composed of two stands, in which high-chromium cast steel centrifugal composite casting rolls are used as work rolls. The temperature is ...

AI Technical Summary

Problems solved by technology

[0008] The main purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, to provide a kind of nodular cast iron that can fully meet the technical requirements of modern hot continuous rolling mills for rough rolling work rolls: roll neck tensile strength ≥ 400MPa, hardness value HSD35-45, and Solve the defects of poor spheroidization, carbide content > 10%, bright spots and gray spots that are common in high-chromium cast steel centrifugal composite casting rolls

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