Research On Microstructure And Properties Of High Chromiun Cast Iron Based On High Entropy Theory

High entropy alloy, a new type of alloy with a variety of elements as the main alloying elements, improves the entropy of the material and stabilizes the material system. It has broad prospects in application due to its simple structure and excellent performance. High chromium and wear resistant cast iron, a traditional wear-resistant material, has high strength and hardness, good wear resistance and corrosion resistance. However its poor impact toughness makes it can not meet the requirements of the actual production with the development of the modern industryIn this paper, the concept of new high entropy alloy was applied in the research of the traditional high chromium wear resistant cast iron. Based on the high entropy theory the chemical composition was designed. The highest content of Cr, B and Mn reached 45%, 2% and 4% respectively much higher than the content in the traditional high chromium cast iron. The effects of B and Mn on the microstructure and properties of high chromium cast iron were studied, and the optimum heat treatment parameters were investigated.The results were as follows:(1) With the increase of B content, the hardness of high chromium cast iron is enhanced. The B content increased from 0% to 2%, the hardness of Cr27C2.5increased from 530 HL to 665 HL, and the hardness of Cr45C4 increased from560 HL to 675 HL.(2) B element is not conducive to the improvement of impact toughness of high chromium cast iron. B content increased from 0% to 2%, the impact toughness of Cr27C2.5 decreased from 1.8J/cm2 to 1.5J/cm2, and the impact toughness of Cr45C4 was reduced from 1.9J/cm2 to 1.4J/cm2.(3) The Mn element could improve the impact toughness of the material.Mn content increased from 1% to 4%, the impact toughness of Cr27C2.5increased from 1.9 J/cm2 to 2.1 J/cm2, and the impact toughness of Cr45C4 increased from 1.5 J/cm2 to 1.7 J/cm2.(4) B is not conducive to the wear resistance of materials. The content of B increased from 0% to 2%, the wear weight loss of Cr27C2.5 increased from 0.4g to 0.5 g, the wear weight loss of Cr45C4 increased from 0.3 g to 0.4 g.(5) The effect of Mn element on the hardness and wear resistance of the material is not obvious.(6) The optimal heat treatment process of Cr27C2.5 and Cr45C4 was determined, and the influence of heat treatment parameters on the mechanical properties was analyzed.The experimental results showed that high chromium wear-resistant cast iron designed according to the high entropy alloy theory has not only high strong hardness, excellent wear resistance and impact toughness. Adding appropriate amount of B and Mn elements effectively improved the mechanical properties and optimized the organizational structure of the material. The reasonable heat treatment process further enhanced the comprehensive mechanical properties of high entropy and high chromium cast iron and improved its organizational structure.