SU1114705A1 - Cast iron - Google Patents

Abstract

CAST IRON, containing z-carbon, silicon, manganese, lanthanum and iron, which is different in teM (which, in order to increase the durability of the strength, it additionally contains samarium in the following ratio of components: tone, wt.%: Hydrode 3.0-3.5 , 8-1.5 Manganese0.4-0.6 Lanthanum 0.05-0.10 Samarium 0.10-0.25 IronEstal

Description

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: l The invention relates to metallurgy, but to them the search for thermally wear-resistant and highly durable white cast irons for mill rolls. Cast iron 1 is known for the following chemical composition, wt.%: Carbon 2.80-3.30 Silicon0.35-0.70 Manganese 0.50- 0.80 Phosphorus Up to 0.26 Sulfur to 0.02 Rare Earth. Metals 0.08-0.12 Magnesium 0.05-0.015 Iron Other The disadvantage of the known iron is low wear resistance. The closest in technical essence and the achieved result to the proposed is cast iron 2 of the following chemical composition, wt.%: Carbon 2.5-3.2 Silicon 0.1–0.5 Manganese 0.2–0.4 Lanthan 0.005-0.15 Iron Else The disadvantages of the famous iron are (Yrack wear resistance and strength. The purpose of the invention is to increase wear resistance. Bones and strength. The goal is achieved by the fact that cast iron containing carbon, silicon, manganese, lanthanum and iron, additionally contains self sary at the following ratio of components %: Carbon 3.0-3.5 Silicon 0.8-1.5 Manganese 0.4–0.6 Lanthanum 0.05–0.10 Samarium 0.10–0.25 Iron Else When determining the required ratio of components, the following were taken into account: Carbon: as its concentration increases to over 3.5 wt.%, The amount of carbide increases in the structure. phase, which provides penetration of hardness, but reduces viscosity, leading to cracking and chipping of the working layer. When the carbon content is below 3.0 wt.%, the amount of the carbide phase sharply decreases, which leads to a decrease in nosostoykost. Silicon within the specified limits is intended to provide the required degree of graphite of cast iron. Increasing its content of 1.5 wt.% Leads to the formation of graphite, which reduces the wear resistance of the iron. O contents below 0.8 wt.% Silicon dramatically deteriorates the casting properties of cast iron. Manganese in the range of 0.4-0.6 wt.% Contributes to the desulfurization and deoxidation of cast iron, allows you to adjust the structure of the metal matrix). With an increase in its content above 0.6 wt.%, The grain enlarges, transcrystallinity appears in the cast iron macrostructure. Reducing the manganese content below 0.4 wt.% C} shzhizha physicomechanical and special properties. Lanthanum within the specified limits helps to increase the dispersion of the matrix, reducing the nominal size of carbides, which entails an increase in wear resistance. With an increase in the content of lanthanum above 0.1 wt.% In the iron, a large amount of sulfides and oxides of lanthanum are formed, which reduce the special properties (wear resistance) of the iron. When the content of lanthanum is below 0.05 wt.%, Lanthanum is consumed in melt refining. Samarium within the specified limits leads to the complete suppression of ledeburite crystallization, increases the dispersion of ausgenite decomposition products, which leads to an increase in wear resistance and strength of white roll iron. An increase in samarium above 0.25 wt.% Leads to the formation of a large amount of nemet; schic inclusions, which contaminate hot cast iron and reduce its durability, and, with contents of less than 0.1 wt. Ledeburitna. Example. Base metal cast iron is melted in an .GGPZ-67M type induction furnace with acidizing. When the temperature reaches 15 00 + 5 ° С, a portion of the cast iron is released into the heated ladle, into which the calculated amount of lanthanum metal is preloaded. Upon reaching 1320C, cast iron is poured into a chill mold. The sample has a height of 200 mm, diameter 50 mm. In the remaining metal in the furnace, the silicon content is adjusted with an additive of ferrosilicon to 0.8-1.5 wt.% And at the same temperature parameters, cast iron is released into the ladle with calculated amounts of lanthanum and samarium, and then poured into chill forms. Samples are cut out of the cylindrical castings obtained in accordance with GOST to determine flexural and tensile strengths, as well as samples for determining wear resistance and metallographic studies. Chemical compositions and test results are given in the table. As a result of research, it was found that the wear resistance of cast iron of the proposed composition in comparison with the known increases by 7- 60, the tensile strength at bending - by 13-33

311147054

and ultimate tensile strength — by 11 — increase their operational durability by 20-27% .30%. The economic effect of the introduction

Use for casting rolled shaft-iron of the proposed composition can reach

for the cast iron of the proposed composition will allow 719.7 thousand rubles.

Claims (1)

CAST IRON containing carbon, silicon, manganese, lanthanum and iron, distinguishing with the fact that, in order to increase wear resistance and strength, it additionally contains' samarium in the following ratio of components. : commodity, wt.%: Carbon 3.0-3.5 Silicon 0.8-1.5 Manganese 0.4-0.6 Lanthanum 0.05-0.10 Samarium • 0.10-0.25 Iron Rest >