Modifying Effect of a New Boron-Barium Ferroalloy on the Wear Resistance of Low-Chromium Cast Iron

Abstract

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.

Influence of boron- and barium-containing modifiers on the structure of low-chromium cast iron

“…It is manifested by increasing precipitation of carbides mainly inside the grains, and not along their boundaries, since boron significantly lowers the surface tension of the grain boundaries, and most of the “active” boron in the solid solution concentrating along the grain boundaries, fills the existing vacancies. This in turn prevents diffusion and reduces carbon segregation along the grain boundaries [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Thus, boron atoms in cast iron, being adsorbed on the surface of the solid phase, deactivate graphite nuclei during crystallization and have a stabilizing (deinoculating) effect on the structure.…”

“…The types of modifiers used, their composition and doses, as well as the methods of the processes of iron smelting, modification and sample preparation are described in detail in this article [ 35 ].…”

“…An earlier study [ 35 ] describes the results of studies of the structure and mechanical properties of low-chromium cast iron modified with boron- and barium-containing modifiers. In this case, the emphasis was placed on the study of the properties of the alloy—resistance to abrasion and cyclic shock-dynamic effects.…”

Establishing the influence of structure parameters of steel on their abrasive wear resistance

“…Materials were tested for abrasive wear using a PV-7 device, which destroys the sample surface as a result of friction [8,9]. Metallographic analysis was performed using a MIM-8M microscope with ×100 and ×1000 magnifications [10].…”

Study of refractory raw materials of the Republic of Kazakhstan

“…It should also be considered that the expansion of the use of secondary raw materials, including carbon-containing ones, is an important factor in the efficiency of the entire industry of the Republic of Kazakhstan [ [4], [5]]. On the other hand, JSC "Kazakhstan Electrolysis Plant" (KEP), which is part of ENRC (Eurasian Natural Resources Corporation) (Pavlodar), annually generates up to 1,500 tons of waste carbon refractory lining and up to 25,000 tons of cinders of baked anodes [ [6], [7]]. with a minimum carbon content of 85 wt.…”