SU1315511A1 - Wear-reststant alloy - Google Patents

Abstract

The invention relates to the development of wear-resistant alloys for cast parts operating under conditions of intense impact-abrasive wear. The purpose of the invention is the development of impact and abrasion resistance, toughness and fluidity. The proposed cast iron contains components in the following ratio, wt.%: With 1.8-3.5; Si 0.5-1.5; MP 1.0-4.0; Cr 15-22.0; V 0.1-3.0; Mo 0.1-0.8; A1 0.03-1.0; REM 0.1-0.25; Ni 0.1-0.5; Ca 0.005-0.015; Ti 0.4-1.0 and Fe else. The addition of Ni, Ca, and Ti to the cast iron provides an increase in impact strength up to 0.9-1.2 kg M / cm and flowability up to 397-413 mm. 2 tab. SL with SP SL

Description

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The invention relates to metallurgy, in particular, to the development of wear-resistant iron-based alloys, used for the manufacture of cast etals of crushing and grinding equipment operating under conditions of intense impact abrasive wear, such as, for example, gutters; crusher lining and hammers, ichi of bead rashers, etc.

The aim of the invention is to increase the toughness, impact-abrasion resistance and fluidity of cast iron.

The choice of the boundary limits of the components in the compositions of cast iron due to the following. The carbon content in the iron 1.8-3.5 wt.%. With a carbon content above 3.5% by weight, and chromium above 22% by weight, the number of brittle hypereutectic carbides in the alloy increases, reducing the toughness and wear resistance.

Manganese introduced into the alloy in an amount of 1.0–4.0 wt.% Is necessary to reduce the rate of austenite decomposition and thereby ensure the greatest toughness of the alloy. A manganese content of less than 1.0 wt.% Does not increase the toughness of the alloy due to a slight decrease in the rate of austenite decomposition, with a manganese content of more than 4.0 wt.%, Austenite is stabilized, thereby reducing the wear resistance of the alloy.

Molybdenum introduced into the alloy, suppressing the diffusion of phosphorus atoms to the grain boundaries, prevents the formation of fragile phosphoric eutectics in these places. By improving the dislocation structure of the alloy and ensuring the hardening of the alloy matrix by doping it, molybdenum increases the impact strength of the alloy. With a molybdenum content of less than 0.1 wt.%, An increase in toughness is insignificant, a content greater than 0.8 wt.% Leads to matrix crossover and, consequently, to a decrease in toughness and wear resistance of the alloy. Vanadium and titanium are introduced into the alloy as strong carbide-forming elements that contribute to the formation of dispersed vanadium and titanium carbides of the MC type, which increase the wear resistance of the alloy, and the content of vanadium and titanium is limited accordingly

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3.0 and 1.0 wt.%, Since with their higher content in the alloy segregation of carbides of these elements is formed and grows, which leads to the embrittlement of the alloy. When the content of vanadium and titanium is below the lower limits (0.1 and 0, D wt.%, Respectively), the number of formed wear resistant MC carbides is small and they do not have a significant effect on the increase in wear resistance.

Nickel contained in the alloy (0.1-0.5 wt.%) Inhibits the diffusion of austenite, i.e. to its stabilization, and contributes to the formation of the austenite-martensitic structure of the alloy, increasing its impact strength. Moreover, the nickel content of more than 0.5 wt.% Leads to an increase in the stabilization of the austenitic structural component of the alloy and to a decrease due to its wear resistance, and less than 0.1 wt.%, The content does not contribute to an increase in impact strength, ,

Calcium introduced into the alloy within the specified limits (0.05-0.015 wt.%) Contributes to the desulfurization of the alloy and the purification of the grain boundaries from non-metallic inclusions, which increases the impact-abrasive wear resistance and fluidity of the alloy. Introduction

Calcium below the lower limit is not effective, since, due to its low content, it does not increase the fluidity and wear resistance of the alloy, and its higher content is undesirable because it violates the homogeneity of the structure — accumulations of carbides form at the grain boundaries, reducing the impact strength and wear resistance of the alloy.

The lower limit of the aluminum content in the alloy is due to its presence in the charge materials, and the upper limit is strongly influenced by the amount of residual austenite in the alloy.

The alloy is melted in a chipboard arc furnace with a base lining. As scrap materials use steel scrap, vanadium pshak, electrode combat and accommodated ferroalloys. Steel, ferro-chrome, vanadium slag, ferromanganese are fed into the filling. By melting the mixture, ferromolybdenum is introduced into the liquid bath, the electrode

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fight, ferrosilicon. Aluminum is supplied to the bottom of the ladle; after filling the ladle, one-third of silicocalcium and rare-earth metals are introduced. Filling temperature 1460-1380 ° С.

The chemical composition of wear-resistant alloys is presented in Table. one; physical and mechanical properties of the proposed alloy and known - in table 2,

The proposed wear-resistant alloy has a double impact strength, 1.5 times impact-abrasive resistance, and 1.1 times the fluidity compared to the known, which is due to the addition of Ni + Ca and Ti to the alloy.

Claims (1)

Formula inventions Wear-resistant alloy containing carbon, silicon, manganese, chromium. Solaa Si Mp Predlozhen- 1J, 740,340,8713,960,070,060,020,060,0030,070.31 21,800,501,0015,000,100,100,030,100,0050,100.40 32,621,132.4818,611,470,35.0,540,330,0100,170.73 43, 501,504,0022,003,100,801,000,500,0150,251.00 53,391,814,2322,963,240,891,210,610,020,291,12 Known 2.07 1.14 1.21 19.16 0.43 0.74 0.52 Vanadium - molybdenum, aluminum, rare earth elements and iron, characterized in that, in order to improve impact and abrasion resistance, impact strength and fluidity, it additionally contains nickel, calcium and titanium in the following ratio of components, wt.%: flaxes 1.8-3.5 0.5-1.5 1.0-4.0 15-22.0 0.1-3.0 0.1-0.8 0.03-1.0 0.1-0.25 0.1-0.5 0.005-0.015 0.4-1.0 Rest Table I The content of the components of us. Remaining "about" 0.13 0, 06 Table 2