SU1388453A1 - Grey cast iron - Google Patents

Description

00 00 00. 4 SP

with

The invention relates to metallurgy, in particular, to finding gray wear-resistant cast irons for work under conditions of high loads and intensive wear under friction with insufficient lubrication,

The purpose of the invention is to increase frost resistance.

The proposed cast iron contains components, masd:

Carbon. 3.3-4.3 Silicon1.6-2.4

Manganese 0.8-1.5

Copper. 0.18-0.65 Zirconium 0.15-0.35

Titan0.12-0.28

Calcium0.02-0.06

Rare earth

metals0.003-0.05

Barium carbide 0.12-0.5 Zinc 0.002-0.1

. Nitrides of one metal from the group,

containing chromium and

vanadium 0.02-0.3

IronErest

The introduction of nitrides of one metal from the group containing chromium and vanadium contributes to the refinement of graphite inclusions and to the improvement of durability and mechanical properties. The lower limits of concentrations, nitrides are taken. - from the values from which their effect on the wear resistance and size of graphite in castings begins to have an effect. As chromium nitride or vanadium concentrations increase by more than 0.3%, a decrease in impact strength, .-. fracture toughness and stability of friction growth back under friction conditions of insufficient lubrication and dry friction

i.

 Supplementary carbide insertion

barium in the amount of 0.12-0.5 wt.% micro-alloying and hardening the metal base, crushing the structure, reducing its embrittlement, blocking defects in the crystalline structure, reducing segregation, increasing the microhardness, matrix and stability of the structure and mechanical properties, which ensures increase in resistance to wear and durability, strength and other mechanical and service properties in mercury; Bari carbide carbide concentration up to 0.12 wt.% micro-alloying effect is weak, significant strengthening of the metal base

it does not achieve endurance, wear resistance, etc., the service properties in castings are low. When the concentration of barium carbides is more,. The plutonic properties, the stability of the structure and the mechanical properties of cast iron in castings are reduced by 0.5 wt.%, Chilling and liquation increase, the stability of the properties and resistance to corrosion are reduced.

The introduction of zinc in an amount of 0.002-0.01 wt.% Increases the hardness, crushes the structure, increases the crack resistance and durability of the matrix, the microhardness of the matrix, its stability in castings, which reduces wear and improves durability, stability of mechanical properties. The zinc content is based on a concentration (0.002 wt,%), which shows an increase in hardness, durability, and wear resistance in castings, and is limited to a concentration of 0.01 wt.%, Whose Bbmie is chilled, a decrease in the dynamic strength and stability of the structure, durability. and others, the properties of cast iron.

The content of the main components. (Carbon 3.3-4.3 wt.%, Silicon 1.6- 2.4 wt.%, And manganese 0.8-1.5 wt.%)

determined by the practice of production of gray wear-resistant cast iron for wear-resistant cast parts. With a decrease in carbon content of less than wt,% and silicon below 1.6 m / s and an increase in manganese concentration of more than 1.5 wt.%, Casting properties decrease, crack resistance, liquation increases, and drought resistance and stability of structure and properties decrease, and at carbon concentrations it is 4 , 3 May,%, silicon more than 2.4 May, and manganese less than 0.8 May,% structure in castings becomes coarse, hardness of carbides and matrix, resistance to wear, wear resistance and stability of mechanical properties in castings decrease.

The alloying of cast iron with copper, zirconium, and titanium provides a substantial increase in the microhardness, solidity of the matrix, and the magnitude of the load causing the α-score. With an increase in their concentration above the upper limits, the stability of the structure decreases, the segregation increases, the dynamic strength decreases, and

resistance and mechanical properties in castings.

REM and calcium are effective modifying additives, retaining the hardness and hardness of pig iron, crushing the structure and increasing the microhardness of cast iron, mechanical properties, wear resistance. When their concentration is less than the lower limits, the modifying effect appears weakly, and when the concentration of REM and calcium is more than 0.05% and 0.06% by weight, respectively, they do not completely dissolve in the matrix, the concentration of non-metallic inclusions increases, their graphitizing effect and heterogeneity structure, which leads to a reduction in jagging, wear resistance, crack resistance and mechanical properties of cast iron in castings

PRI me R, OPB1tnye melting of cast iron held in an induction furnace with a capacity of 200 kg using cast iron pig. In the brand LK-1, LK-2, pig iron M2 and PL-1, cast iron 17 A, silico-manganese SMISTAL scrap, nitrides chromium, briquettes, nitrides of vanadium, titanium, copper, ferrosilicon, silicocalcium, zirconium master alloy and other ferroalloys. The cast iron was superheated to 1480 and released into casting buckets with zirconium ligature, briquettes of vanadium nitride, chromium, barium carbides, zinc and modifying additives. Briquettes of nitrides were crushed to a fraction of 0.2-2 mm. Cylindrical specimens with a diameter of 30 mm, technological step samples with a maximum thickness of 20 mm and castings of wear-resistant parts were cast from cast iron. The absorption of zirconium was 78-85%; chromium nitrides 88-93%; vanadium nitrides 90-96%; zinc 67-73%, barium carbides 72-76%.

Table 1 shows the chemical compositions of the cast irons of the experimental heats.

Samples and castings were tested in a cast state.

0

five

five

0

0

five

0

Table 2 presents data on zadrostoykost, wear resistance, mechanical and performance properties.

The relative wear resistance was determined according to GOST 23.213-82 on wear-resistant castings with a wall thickness of 30-40 mm. On the same blanks with a wall thickness of 30-40 mm, the resistance to air resistance was checked.

As can be seen from Table 2, the proposed cast iron has a higher shear resistance compared to the base iron. High operational durability under conditions of intense wear is achieved by producing a finely dispersed metal base, increasing its microhardness, resistance to wear and durability.

Claims (1)

Invention Formula Gray cast iron containing carbon, silicon, manganese, titanium, zirconium, copper, calcium, rare earth metals and iron, characterized by the fact that, in order to improve its resistivity, it additionally contains zinc, barium carbides and nitrides of one metal from the group containing chromium and vanadium, in the following ratio, wt.%: Carbon five 0 Silicon Manganese Titanium Zirconium Copper Calcium Rare earth metals zinc Barium carbides Nitrides of one metal from the group containing chromium and vanadium Iron 3.3-4.3 1.6-2.4 0.8-1.5 0.12-0.28 0.15-0.35 0.18-0.65 0.02-0.06 0.003-0.05 0.002-0.01 0.12-0.5 0.02-0.3 Rest. Table Strength limit at rass-. t, MPa 250 412 442 484 415 448 486 278 392 279398 Shock viscosity MCG / M 0.75 0.92 0.98 0.95 0.94 0.98 0.96 0.78 0.86 0.79 0.88 Wear at semi-dry friction, µm / h 0.850.23 0.18 0.14 0.22 0.17 0.13 0.83 0.27 0.83 0.25 Time to education bully h12.4 41.7 52.2 58.6 42.6 54.5 59.8 13.2 36.6 13.6 38.3 Operation. tatsionna resistance 100,142,174,186,148,180,130,131,113,133 Relative I9NOSO- 1.85 4.24 4.84 5.26 4.28 4.95 5.32 2.08 2.96 2.12 3.26 persistence in. castings with a wall thickness of 30-40. Ml, ZadirostovKocTk at. semi-dry friction, MPa m / s - 960 2380 2412 2460 2392 2418 2480 1020 1610 10 51870