SU975824A1 - Cast iron - Google Patents

Description

The invention relates to metallurgy, mainly to the production of cast iron used as a material in the manufacture of chill molds in foundry. The disadvantages of these cast irons are low durability (from 36 to 121 cycles) and low strength.

Cast iron of the following composition is also known.

leadership. wa, weight. %: 5 Carbon 3.1-3.4 Known cast iron [I] intended Silicon 1.5-1.7 for the manufacture of chill molds, molds, contents Niobium 0.2-0.3 living in its composition, weight. %: Manganese 0.3-0.4 Have carbohydrate 3.2-3.8 Chromium 0.15-0.25 Silicon 1.8-2.6 10 Titanium 0.08-0.12 Manganese 0.1-0.5 Copper 0.6-1.0 Chromium 0.1-0.6 Molybdenum 0.4-0.6 Molybdenum 0.1-0.6 Iron Rest Nickel 0.5-3.5 Properties of this cast iron: ultimate strength Iron Rest tensile 30.2—38.5 kgf / mm ² , limit fifteen strength at bend 51.5–61.5 kgf / mm ² , Known also cast iron [2], containing- growth resistance 0.06-0.15%, heat-resistant

weight %:

Carbon 3.0-3.5 Silicon 0.2-1.0 Manganese 0.3-0.8 Chromium 0.1-0.5 Nickel 0.1-0.4 Aluminum 0.8-2.0 Calcium 0.002-0.05 Iron Rest

bone 880-1260 cycles [3].

However, the mechanical strength and heat resistance of said cast iron do not provide ₂₀ for a long service life of the chill molds made from it.

The closest in technical essence and the achieved result is cast iron [4] of the following chemical composition, weight. %:

Carbon 2.9-3.4 Silicon 2.4-2.8 Manganese 0.4-0.8 Aluminum 3.2-3.9 Cerium 0.02-0.06

Chrome 0.8-1.6

Magnesium 0.08-0.14

Iron Else

The properties of cast iron in the cast state are presented in table. one.

Table 1

Additives magnesium the weight.% Dobki chrome, weight. % Hardness HB Bending strength, kg / mm ² Tensile strength, kg / mm ² Scale resistance, g / m h 0.08 0.8 237 66 32,5 0.01 0.11 1,2 248 69 34.0 0.01 0.14 16 262 70 35,2 0.01

The disadvantages of the known cast iron are low strength and heat resistance 20 (2640 cycles).

The aim of the invention is to increase the strength and heat resistance.

This goal is achieved by the fact that cast iron containing carbon, silicon, manganese, chromium, aluminum, cerium, magnesium and iron, additionally contains molybdenum

ι, the following%: ratio of components Carbon 3.3-3.7 Silicon 1.5-1.9 Manganese 0.1-0.2 Chromium 0.9-1.1 Aluminum 0.4-3.5 Magnesium 0.08-0.14 Cerium 0.02-0.06 Molybdenum 0.2-0.4 Iron Rest As impurities cast iron contains

sulfur (not more than 0.03 wt.%) and phosphorus (not more than 0.3 wt.%).

Combined alloying, desulfurization, and θ ₄ desorption and modification of cast iron with aluminum, magnesium, and cerium in the presence of chromium and molybdenum provide a stable metal mass (ferrite) and a film that prevents the penetration of the oxidizing gas phase, a sharp increase in the life of chill molds (their durability).

Magnesium is introduced in the form of an alloy with aluminum, and cerium is given into the bucket before pouring, which completes the modification process to obtain spherical graphite.

Cast iron was smelted in an induction furnace with an acid lining. As the charge was used cast iron and cast iron scrap as calculated. The desired chemical compositions were obtained by the addition of aluminum and magnesium in an alloy of AL 13, ferromolybdenum Mo 3, ferrochrome F.X 650 V and modified with ferrocerium. The alloy was overheated in an oven to 1450–1470 ° С; the alloy was cast at 1340–1360 ° С.

In the table. 2 shows the compositions of cast irons according to the invention, and in table. 3 - test data of mechanical properties and heat-resistant

Components The content of components, weight. ^2. , In cast iron one ! ² [.FROM. ± 2 .... ί ..? ... .-1 ... 2-. 2 „2. G one l 8 Carbon 3Λ5 evil 3.30 3.36 3.29 3.57 3,7 3.34 Silicon 1, 60 1,50 1, 67 1, 70 1.65 1.90 1.84 1.48 Manganese 0.13 0.15 0.12 0.18 0.10 0.20 0.14 0.11 Phosphorus 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 Sulfur 0,022 0,025 0,029 0,03 0.024 0.016 0,028 0.03 Chromium 1.10 1, 02 0.99 0.98 0.95 0.90 one hundred 1,07 Molybdenum 0.36 0.40 0.29 0.30 0.27 0.20 0.35 0.27 Aluminum 0.60 0.32 1, 98 2.68 3,50 3.21 2.44 3.90

Continuation of the table. 2

Content of components, weight 4, in cast iron

gchim! ιυ ms gui s 2 17 -u -.one four 6 8 5 Magnesium oh 0.12 0.13 0.09 0.08 0.09 0.14 0,07 Cerium 0,03 0.02 0.05 0.06 0,03 0.02 0,03 0.04 Iron Rest Rest Rest Rest

Table 3

Indicators Cast iron one 2 s 5 . [.. 7 ....! 8 Tensile Strength, kgf / mm ² 46.6 48.1 51.6 59.4 56.0 61,4 52.7 49.6 Bending strength, gf / mm ² 82.3 89.1 92.4 105,4 94.6 112.6 90.9 73.6 Growth resistance,% 0.15 0.12 0.10 0.04 0.02 0.01 0.08 0.11 Hardening, mg / m ² h 0.14 0.04 0.01 0.007 0.007 0.002 0.009 0.14 Heat resistance cycle 6450 6700 6980 7410 7200 7540 7150 5900

Improving the strength and more than 2 times the heat resistance of the castings of the proposed cast iron compared to s ₅ with the known is provided due to the presence of molybdenum, as well as the ratio of components.

Cast iron is supposed to be mastered at the Gomel Belemalpososda plant of the MMP BSSR as a material for the manufacture of large-sized ⁴⁰ large-sized chill molds 1000 X 900 X 350 mm weighing 900 kg.

The estimated economic effect of using the proposed cast iron at this enterprise will be 100 thousand rubles. _<5 per year.

Claims (1)

Cast iron containing carbon, silicon, ₅₀ manganese, chromium, aluminum, magnesium, cerium and iron, characterized in that, in order to increase strength and heat resistance, it additionally contains molybdenum at the following relation components. the weight. %: Carbon 3.3-3.7 Silicon 1.5-1.9 Manganese 0.1-0.2 Chromium 0.9-1.1 Aluminum 0.4-3.5 Magnesium 0.08-0.14 Cerium 0.02-0.06 Molybdenum 0.2-0.4 Iron Rest Information sources,