This paper presents the results of a study and analysis of the effect of modifying low-chromium hypoeutectic cast iron with a new boron–barium ferroalloy on its properties—wear resistance and impact resistance—in comparison with traditional boron- and barium-containing additives. The uniqueness and novelty of the work lies in the study of the nature of changes in the structure and wear-resistant properties of low-chromium cast iron as a result of its modifying treatment with a new boron–barium ferroalloy. In a laboratory electric resistance furnace, low-chromium cast iron was melted, and four batches of prototypes were cast. Samples of the first batch, for subsequent comparison, were made without modification. When casting the remaining three batches of samples, the cast iron was modified with three different additives: ferroboron FeB12, ferrosilicobarium FeSi60Ba20, and a new complex boron–barium modifier. In order to compare the degree of effectiveness of the applied modifiers, a metallographic analysis of the structure was performed, hardness measurements were performed on the surface of the samples, and they were subjected to abrasion and cyclic shock-dynamic impact tests. In all cases, when modifying cast iron, there was an increase in hardness, a noticeable grinding of the microstructure, and a redistribution of structural components towards an increase in the proportion of perlite and finely dispersed ledeburite. A comparative analysis of the results of testing samples for dry friction and shock showed a higher surface resistance of cast samples made of modified cast iron compared to unmodified low-chromium cast iron of the same composition. A comparative study of the parameters of wear tracks and craters on damaged surfaces established that the most optimal combination of wear-resistant qualities of low-chromium cast iron occurs when it is treated with a complex boron–barium modifier, which is also evidenced by obtaining a more favorable microstructure.

No abstract

MATHEMATICAL DESCRIPTION OF STATE DIAGRAMSAnnotation. A mathematical model of the state diagram of the Fe -Fe3C system has been created. It is based on the mathematical description of the equilibrium lines of the diagram. According to the obtained algorithm, a computer program was developed. When setting the carbon content in the metal under study and the temperature from the remote control, the computer finds the required area, calculates and displays the phase composition in mass percent on a monitor or print. No obstacles are foreseen for the creation of mathematical models for other binary systems.

The paper presents the results of industrial testing parts made of experimental wear-resistant alloys. Cast iron was smelted with a high content of nickel and vanadium and steel with alloying elements, which vary widely over from 15% to thousandths. The prototypes wear resistance was increased by about 30-34%. The work was performed at Karaganda State Technical University. These studies were carried out as a part of the grant of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan BR05236295 “Designing, Developing and Implementing Technologies of Producing and Machining New Generation Wear-Resistant Materials for Obtaining Parts of Metallurgical Units”.

No abstract