RU2230819C1 - Atmospheric corrosion-resistant low-alloyed steel - Google Patents

Abstract

FIELD: STEELMAKING.

SUBSTANCE: steel that can be employed in manufacture of undyed units of contact system of electrified railway contains, wt %: carbon 0.06-0.18, silicon 0.15-0.6, manganese 0.5-1.2, chromium 0.6-1.3, nickel 0.4-0.8, copper 0.3-0.7, aluminum 0.005-0.05, titanium 0.005-0.04, vanadium 0.01-0.05, phosphorus 0.01-0.04, and iron - the balance.

EFFECT: increased resistance against general and pitting corrosion in industrial and urban atmospheres and also increased impact elasticity at negative temperatures.

2 cl, 2 tbl

Description

The invention relates to metallurgy, to iron-based alloys, namely to atmospheric corrosion resistant low alloy steels, and can be used in the electrification of railways for the manufacture of unpainted load-bearing structures of the contact network.

Known atmospheric corrosion-resistant low alloy steels, the level of corrosion and mechanical properties of which are close to the claimed (see, for example, Japanese patent No. 59-227942, MKI C 22 C 38/50, 1986 and the USSR AS No. 998572, class C 22 C 38/50, 1981).

Known steels contain carbon up to 0.14%, silicon up to 0.75%, manganese up to 1.6%, chromium up to 1.5%, phosphorus up to 0.15%, nickel up to 1%, copper up to 0.6%, one or more elements from the group of niobium, vanadium, titanium up to 0.2%.

These steels are characterized by sufficiently high mechanical properties - yield strength up to 490 N / mm, temporary resistance up to 650 N / mm ² .

During long-term operation, low alloy steels are used in painted form, for example, for the manufacture of bridge spans. Unpainted structures made of ordinary low-alloy steel, operated in a slightly to medium aggressive atmosphere, exhibit an increased tendency to general and pitting corrosion.

The closest in technical essence and the achieved result is low alloy steel of the following chemical composition (wt.%):

This steel has the following properties:

The disadvantage of steel is the reduced resistance to general and pitting corrosion during prolonged use of unpainted structures in slightly and medium aggressive atmospheres, as well as the relatively low cold resistance, insufficient for using steel in the northern regions of the country.

The technical result of the invention is to increase the resistance against general and pitting corrosion in slightly and medium aggressive atmospheres, as well as increase the impact strength at low temperatures.

The technical result of the invention is achieved in that the steel, including carbon, silicon, manganese, chromium, nickel, copper, aluminum, titanium, additionally contains vanadium and phosphorus in the following ratio of components (wt.%):

In addition, steel may additionally contain cerium in an amount of 0.001-0.005% (as USSR AS No. 1065497, class C 22 C 38/50, 1984).

It was experimentally established that after heat treatment, steel has the following mechanical and corrosion properties (not less):

An example of the method of steelmaking

In 50 kg of induction furnace six melts of steel of the following chemical composition (wt.%) Were smelted: tab. No. 1.

In the state of supply of steel they have the following properties (not less): tab. No. 2.

Claims (2)

1. Atmospheric corrosion-resistant low alloy steel, including carbon, silicon, manganese, chromium, nickel, copper, aluminum, titanium and iron, characterized in that it additionally contains vanadium and phosphorus in the following ratio, wt.%: Carbon 0.06-0.18 Silicon 0.15-0.6 Manganese 0.5-1.2 Chrome 0.6-1.3 Nickel 0.4-0.8 Copper 0.3-0.7 Vanadium 0.01-0.05 Phosphorus 0.01-0.04 Aluminum 0.005-0.05 Titanium 0.005-0.04 Iron Else 2. Steel according to claim 1, characterized in that it further comprises cerium in an amount of 0.001-0.005%.