Manufacturing method for multi-component alloying steel with high strength and high wear-resistance and hot rolled plate thereof

Abstract

This invention provides a manufacturing method of a multi-component alloying steel with high strength and high wear-resistance and a hot rolled plate thereof. The weight percentages of the chemical composition of the wear-resistant steel above is as follows: C: 1.0-1.2%, Si: 0.6-1.0%, Mn: 8.0-10.0%, P<0.02%, S<0.02%, Cr: 1.5-2.5%, Mo: 0.2-0.5%, V: 0.6-1.0%, Nb: 0.02-0.06%, Ti: 0.01-0.1%, Al: 0.03-0.08%, and the rest are Fe and unavoidable impurities. The manufacturing process of the hot rolled plate of the wear-resistant steel includes the steel making, continuous casting, heating, hot rolling and heat treatment.

Description

BACKGROUND1. Field of the Invention[0001]This invention is related to a technical field of high strength and high wear resistant hot-rolled steel. In particular, this invention is related to a manufacturing method of multi-component alloying steel with high strength and high wear resistant and a hot rolled plate thereof.2. Description of Related Art[0002]At present, the widely used wear resistant steel in the coal-mining field is the medium and low alloy wear-resistant steels. The representative steels include the HARDOX series of Sweden (abbreviated as HD series below), EH series of JFE in Japan, NM series of Wuhan Iron and Steel Group Corp. and B-HARD series of Baosteel. The medium and low alloy wear-resistant steel is a type of low-carbon steel with the martensite or martensite-bainite complex microstructure after quenching and tempering. The wear resistance of this kind of wear resistant steel, especially the thick plate, is obviously attenuated from the surface to the heart, wh...

AI Technical Summary

Benefits of technology

The invention is about a hot rolled medium manganese wear-resistant steel with high strength and high wear resistance. By optimizing the composition and content of alloying elements and rationally adjusting the ratio of C and Mn elements, and adding Ti, V, Nb and other micro-alloying elements in steel, the crystal grains can be refined and alloy carbides can be formed with C element. After solid solution treatment, these carbides disperse in crystal grains and obtain a second phase strengthening effect, which increases the strength, hardness and wear resistance of steel.

Problems solved by technology

The wear resistance of this kind of wear resistant steel, especially the thick plate, is obviously attenuated from the surface to the heart, which is the main disadvantage of the martensite-bainite wear resistant steel.

In addition, it is found that the applied effect of medium and low alloy martensite-bainite wear resistant steel is not ideal under the impact and fatigue working conditions in production practice.

Although the medium and low alloy wear resistant steel has relatively good impact toughness, the fatigue stress cracking is easy to occur in this wear resistant steel during long-term service under the impacting wear condition, which will affect the service life.

At this time, the performance of low alloy wear resistant steel has been unable to meet the complex working conditions of coal mining.

However, in practical application, it is found that the impact energy provided in the coal mining process is not enough to fully exert deformation hardening ability of the high manganese steel.

The hardening coefficient of high manganese wear resistant steel is low, and the degree of deformation hardening does not reach the ideal value.

Therefore, the strengthening effect and wear resistance are not satisfactory in some typical application fields, such as the lining plate of ore crusher, material transport pipeline, bucket teeth of excavator and crawler board of middle trough of scraper conveyor.

When the coal mining machine is running in underground mine, the middle trough of scraper conveyer bears the violent friction of coal, scraper and chain, and is subjected to the effect of friction wear, such as abrasive wear, impacting wear and so on.

In addition, the middle trough is also subjected to the action of the operating load of coal mining machine, lateral and longitudinal force of hydraulic support, extrusion and impact forces of large coal and rock blocks stuck in the middle trough.

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