RU2303076C1 - Wear-resistant steel "ssil-600" - Google Patents

Abstract

FIELD: ferrous metallurgy.

SUBSTANCE: invention relates to cast steels and can be used to manufacture ladle teeth and excavator wheels operated in various climatic zones. Steel according to invention comprises, wt %: carbon 0.38-0.45, silicon 0.40-0.50, manganese 0,80-1,20, chromium 2.00-2.50, molybdenum 0.20-0.30, nickel 1.30-1.60, copper at most 0.30, vanadium 0,10-0,15, calcium 0.005-0.01, cerium 0.005-0.01, aluminum 0.03-0.06, and iron - the balance. Choice of elements for alloying steel is determined by required properties and cost.

EFFECT: increased wear resistance in operation of excavator in various rocks.

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Description

The invention relates to the field of metallurgy, and more particularly to cast steels used in excavation for the manufacture of teeth of buckets and wheels of excavators operating in different climatic zones.

Steel is known (see the catalog "Stahlschlüssel" 45NiCr6 1986, p. 193, No. 1.2710 ed. MVND-7142), trace. composition, wt.%:

Carbon 0.40-0.50 Silicon 0.15-0.35 Manganese 0.50-0.80 Sulfur no more than 0,35 Phosphorus no more than 0,35 Chromium 1.20-1.50 Nickel 1.50-1.80 Iron rest

The closest in composition adopted as a prototype is steel grade 40X2H2MA (GOST 4543-71), used in industry, of the following composition, wt.%:

Carbon 0.35-0.42 Silicon 0.17-0.37 Manganese 0.30-0.60 Sulfur no more than 0,025 Phosphorus no more than 0,025 Chromium 1.25-1.65 Molybdenum 0.20-0.30 Nickel 1.35-1.75 Copper no more than 0.30 Iron rest

This steel does not provide wear resistance in highly abrasive rocks.

The objective of the invention is to provide increased wear resistance in various rocks.

The solution to this problem is achieved by the fact that in the steel containing C, Si, Mn, Cr, Mo, Ni, Cu, V, Ca, Ce, Al are additionally introduced in the following ratio of components, wt.%:

Carbon 0.38-0.45 Silicon 0.40-0.50 Manganese 0.80-1.20 Chromium 2.0-2.50 Molybdenum 0.20-0.30 Nickel 1.30-1.60 Copper no more than 0.30 Vanadium 0.10-0.15 Calcium 0.005-0.01 Cerium 0.005-0.01 Aluminum 0.03-0.06 Iron rest

The choice of elements for alloying the selected steel grade was determined by the required properties and cost.

Carbon in steel in an amount of C = 0.38-0.45% was selected in order to ensure high wear resistance, high ductility, and reduce brittleness.

Manganese in steel in an amount of Mn = 0.80-1.20% is selected from the condition of ensuring full deoxidation of the steel, increasing hardenability and lowering the temperature of the cold brittleness threshold.

Nickel in steel in the amount of Ni = 1.30-1.60% provides an increase in ductility, toughness, cold resistance and corrosion resistance.

Silicon in steel in the amount of Si = 0.40-0.50% is an active deoxidizer of steel and reduces the sensitivity to overheating.

Aluminum in steel in an amount of Al = 0.03-0.06% provides complete deoxidation of the steel and contributes to obtaining a fine-grained structure.

Copper in an amount of not more than 0.30% is selected to increase corrosion resistance in a humid atmosphere.

Example.

Known and proposed compositions of steels were smelted in induction furnaces IST-16 and cast into molds of 50 kg. The heat treatment consisted of quenching 30-50 ° C above AC ₃ and tempering at a temperature of 180 ° C. The heat treatment mode and tempering temperature of the steel should be selected depending on the strength of the rock and the specific ambient temperature.

Table 1 shows the chemical compositions of the proposed and known steels.

Table 1 steel grade Chemical composition, wt.% FROM Mn Ni Si Mo Xie Al Cr V Sa Cu S R Famous 0.36 0.40 1.40 0.30 0.30 - - 1,58 - - 0.24 0.015 0.016 Suggested 1 0.36 0.74 1,02 0.34 0.19 0.002 0.28 1.74 0,07 0.004 0.11 0.015 0.018 Suggested 2 0.38 0.81 1.32 0.40 0.23 0.006 0,035 2.11 0.11 0.007 0.13 0.014 0.017 Suggested 3 0.42 0.87 1.45 0.47 0.23 0.006 0,040 2,34 0.12 0.007 0.12 0.016 0.018 Offered 4 0.45 1.18 1.55 0.49 0.28 0.008 0,055 2.44 0.14 0.008 0.09 0.010 0.015 Offered 5 0.46 1.25 1.90 0.60 0.53 0.015 0,066 3.33 0.15 0.016 0.11 0.016 0.019

The mechanical properties of the considered steel grades and tests for abrasive wear were carried out under the conditions of Izhora Plants OJSC (St. Petersburg, Russia) and Siegen University (Germany). Depreciation was determined on cylindrical samples by friction against rocks of various hardness. The tests were carried out at initial temperatures of + 20 ° C and -80 ° C.

The test results after quenching and tempering at a temperature of 200 ° C are given in table 2.

table 2 No. of swimming trunks σ _in , MPa HB Quartz wear resistance, m / g Test temperature + 20 ° С -40 ° C + 20 ° С + 20 ° С -80 ° C Known 0 1650 1662 550 104 98 Suggested 1 1770 1780 590 110 105 Suggested 2 1780 1794 596 114 107 Suggested 3 1802 1817 600 118 112 Offered 4 1797 1810 600 129 120 Offered 5 1785 1794 595 126 115

The data presented show that the introduction of new components into the steel composition together with components of known composition can increase the wear resistance of the material.

Claims (1)

Wear-resistant steel containing carbon, silicon, manganese, chromium, molybdenum, nickel, copper and iron, characterized in that it additionally contains vanadium, calcium, cerium, aluminum in the following ratio, wt.%: Carbon 0.38 - 0.45 Silicon 0.40 - 0.50 Manganese 0.80 - 1.20 Chromium 2.0 - 2.50 Molybdenum 0.20 - 0.30 Nickel 1.30 - 1.60 Copper no more than 0.30 Vanadium 0.10 - 0.15 Calcium 0.005 - 0.01 Cerium 0.005 - 0.01 Aluminum 0.03 - 0.06 Iron rest