A Method to Simultaneously Improve the Hardness and Toughness of (cr,fe)7c3

Abstract

The invention belongs to the field of mixture of metal powder and nonmetal powder and particularly relates to a method for simultaneously improving hardness and toughness of (Cr,Fe)7C3. The method comprises the following steps that (1) scrap steel, pig iron, high-carbon ferro-chrome, low-carbon ferro-chrome and ferrotungsten are adopted as raw materials, and the components comprise, by weight, 4.2%-4.8% of C, 11.5%-12.3% of Cr, 0.08%-0.13% of Ti, 1%-1.6% of Si, 0-3.5% of W, and the balance Fe; (2) all the raw materials in the step (1) are smelted, after the temperature of molten metal reaches 1450-1500 DEG C, deoxygenation is conducted through aluminum wires, then the molten metal is cast into a sand mold through a casting ladle, and natural cooling is conducted; (3) a casting made in the step (2) is cleaned up and then subjected to quenching treatment, and then air cooling is conducted; and (4) the quenched casting in the step (3) is subjected to tempering treatment, heat preservation is conducted for a certain period of time, and then air cooling is conducted. Through the method, the mechanical property of (Cr,Fe)7C3 carbide in high-chromium cast iron can be improved significantly, the process is simple and easy to conduct, the defect that in the prior art, the shape and distribution of primary carbides are improved only through modification treatment is overcome, and the method is suitable for batch production.

Description

technical field [0001] The invention belongs to the field of mixtures of metal powder and non-metal powder, in particular to a method for simultaneously improving the hardness and toughness of (Cr, Fe)7C3. Background technique [0002] For a long time, due to its excellent wear resistance, relatively low price and simple preparation process, high chromium cast iron has been widely used in anti-wear environments. The excellent anti-wear performance is mainly derived from the high volume fraction of wear-resistant M 7 C 3 Type (HV~1300-1800) The existence of hard phase, and also related to the toughness of the matrix. According to the ratio of carbon and chromium, high chromium cast iron can be divided into hypoeutectic, eutectic and hypereutectic, among which hypereutectic high chromium cast iron has the highest volume fraction of wear-resistant M 7 C 3 type hard phase. Therefore, in order to better develop and apply hypereutectic high-chromium cast iron, the primary car...

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Problems solved by technology

[0006] Chinese invention patent CN1769508 discloses a low-cost, high-wear-resistant hypereutectic high-chromium cast iron and its manufacturing method. The method of secondary inoculation and modification is used to refine primary carbides. The effect of using an inoculant is to greatly accelerate the alloying process. Solidification, so that the primary carbides do not have time to grow up, so as to achieve the purpose of refining the primary carbides, but it does not change the mechanical properties of the primary carbides such as hardness and toughness

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