SU540937A1 - Cast iron - Google Patents

Description

The invention relates to the field of metallurgy, in particular, to the manufacture of cast iron for the manufacture of rolls, grinding media and other wear-resistant parts.

Known cast iron following chemical composition, weight. %:

3.0-3.6 Carbon 2.8-3.5 Silicon 0.6-2.0 Manganese Chrome

5.0-6.5

Aluminum 1.0-1.5 O Steel Iron

This cast iron is highly wear-resistant due to the fact that it has a hardness of .400-520 HB and in its structure 11) carbide phase: for is a chromium-isto-carbide type. At the same time, the strength strengths of this cast iron, especially for massive castings, for example in large rolling rolls, are insufficient. The flexural strength of specimens from the cheeks of large rolling rolls is 38-45 kgf / mm. This is due to the fact that in these castings large, inclusions of lamellar graphite are released.

Iron wear is 0.029 g (weight loss).

The closest to the described invention 1PO technical essence and the achieved result is cast iron of the following chemical composition, weight. %:

Carbon

1.8-3.6

Silicon

2.6-3.4

Manganese

0.4-5.0

5.0-6.5

Chromium

Copper

0.1-1.8

Aluminum

0.01-0.9

Cerium

0.01-0.3

0.01-0.3

Calcium

Molybdenum

0.01-1.2

Rest

Iron

After quenching, the air has the following properties:

Strength at

bending, kg / mm 44-47

Hardness HRC, kg / mm 56-58

IzNos (weight loss), g0,0293

The disadvantages of the known cast iron are their wear resistance and strength. The aim of the invention is to increase wear resistance and strength.

This goal is achieved by the fact that cast iron containing carbon, silicon, manganese, chromium, copper, aluminum, one or more elements from the group of cerium and calcium, and Lselezo, additionally contains magnesium, the following ratio of components, dog. %: Carbon2.5-3.2

Silicon2.0-2.9

Manganese 0.2-0.8

Chrome4.4-5.0

Copper0,1-2,0

Aluminum 0.2-2-1 One or more elements

FROM cerium group and

.calcium 0.005-0.05

Magai0.03-0.06

IronErest

Chugui may contain, instead of cerium and calcium, an element issued from a group containing yttrium and lanthanum.

Cast iron in impurities may contain phosphorus up to 0.15 (wt.%, Sulfur up to 0.02 wt.%.

The iron is smelted in an acid crucible induction furnace. All alloying elements are introduced into the crucible in a crucible furnace. Modifiers in the form of a silicon-mash alloy containing 5-6% magnesium and ferroceri containing 50-55% certs and lanthanum (in total) are placed on the bottom of the ladle in front of the metal into it. The cast iron at a temperature of 1490-1500 ° C is released from the furnace into the ladle, moves, and when the temperature reaches 1310-1330 ° C is poured into dry forms from sandy-clay mixture.

The chemical composition and mechanical properties of the proposed cast iron are given in the table.

Wear resistance is determined under the conditions of friction sliding of the proposed iron together with art. 3 when loading 75 kg. Test cycle of 5000 revolutions of the counter piece.

The use of the proposed cast iron for casting, for example, mill rolls, improves their strength and durability: bone, which provides an improvement in the quality of rolled products and an increase in the productivity of rolled steel.

mills

Claims (2)

Invention Formula Cast iron containing carbon, silicon, manganese, xpOiM, copper, aluminum, one or more elements from the group of cerium and calcium, and iron, characterized in that, in order to increase strength and durability, it additionally contains magnesium in the following component ratio, weight . %: Carbon2.5-3.2 Silicon2.0-2.9 Manganese 0.2-0.8 Chrome4.4-5.0 Copper0,1-2,0 40Aluminium0.2-1.0 One or more elements from the group of cerium and Calcium 0.005-0.05 Mapniy0.03-0.06 45 Iron Else 2. Chugzn according to claim 1, characterized in that it contains, instead of crystals and calcium, an element selected from the group comprising yttrium and lanthanum.