RU2557196C1 - Cast iron - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: cast iron contains in wt %: carbon 3.6-4.0; silicon 0.4-0.8; manganese 1.4-2.0; chromium 0.2-0.3; nickel 0.3-0.8; titanium 0.002-0.005; hafnium 3.0-4.0; niobium 0.2-0.3; molybdenum 3.0-4.0; iron - the rest.

EFFECT: increased cast iron resistance to torsion at high temperatures.

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Description

The invention relates to the field of ferrous metallurgy, in particular to compositions of cast iron, which can be used in mechanical engineering.

Known cast iron of the following composition, wt. %: carbon 3.6-3.9; silicon 0.35-0.85; manganese 1.4-1.9; chrome 0.05-0.3; nickel 0.3-0.8; titanium 0.01-0.05; phosphorus 0.2-0.4; copper 1.8-2.6; nitrogen 0.01-0.03; iron - the rest [1]. The torsion resistance of such cast iron at 800 ° C is 363-402 MPa.

The objective of the invention is to increase the torsion resistance of cast iron at elevated temperatures.

The technical result is achieved by the fact that cast iron containing carbon, silicon, manganese, chromium, nickel, titanium, iron, additionally contains hafnium, niobium and molybdenum, in the following ratio of components, wt. %: carbon 3.6-4.0; silicon 0.4-0.8; manganese 1.4-2.0; chrome 0.2-0.3; nickel 0.3-0.8; titanium 0.002-0.005; hafnium 3.0-4.0; niobium 0.2-0.3; molybdenum 3.0-4.0; iron is the rest.

The table shows the composition of cast iron.

Table Components Composition, wt.%: one 2 3 Carbon 3.6 3.8 4.0 Silicon 0.8 0.6 0.4 Manganese 2.0 1,6 1.4 Chromium 0.2 0.25 0.3 Nickel 0.3 0.5 0.8

Table continuation Components Composition, wt.%: one 2 3 Titanium 0.005 0.003 0.002 Hafnium 4.0 3,5 3.0 Niobium 0.3 0.25 0.2 Molybdenum 3.0 3,5 4.0 Iron rest rest rest

The torsion resistance of cast iron at 800 ° C will be ~ 450 MPa for all the compositions listed in the table.

In the composition of cast iron, the components manifest themselves as follows. Hafnium, chromium, molybdenum and niobium increase the strength characteristics of the alloy, increase torsion resistance at elevated temperatures. Chrome and boron stabilize carbides. Nickel prevents the formation and development of cracks in cast iron products. Titanium prevents the formation of shells in iron castings.

Cast iron is smelted in electric furnaces and cast into hot (400-500 ° C) metal molds coated with refractory clay. To relieve internal stresses, castings are annealed at a temperature of 600 ° C.

The source of information

1. SU 1636471, C22C 37/10, 1991.

Claims (1)

Cast iron containing carbon, silicon, manganese, chromium, nickel, titanium and iron, characterized in that it additionally contains hafnium, niobium and molybdenum, in the following ratio, wt.%: Carbon 3,6-4,0, silicon 0 , 4-0.8, manganese 1.4-2.0, chromium 0.2-0.3, nickel 0.3-0.8, titanium 0.002-0.005, hafnium 3.0-4.0, niobium 0 , 2-0.3, molybdenum 3.0-4.0, iron - the rest.