SU863707A1 - Steel - Google Patents

Description

(54) STEEL

one

This invention relates to metallurgy, in particular to low alloy steels for pipelines.

Known steel 1, containing, wt.%:

Carbon0.10-0.25

Manganese 0.5-0.20

Silicon0.2 -0.6

Copper0.2 -2.0

Nickel 0.6

Vanadium 0.1 -0.4

Aluminum 0.06

Chrome 0.3

IronErest

This steel can be used for pipelines, but in the state after rolling it has an insufficient level of mechanical properties for the manufacture of large diameter gas and oil pipelines.

Known steel 2, containing, wt.%:

Carbon 0.01-0.10

Silicon0.05-1.0

Manganese 0.2 -2.5

as well as one or more components from the group:

to

After hot impregnation, this steel does not allow a sufficient level of mechanical properties and toughness.

ts

Closest to the proposed technical essence and the achieved result is steel (31, containing, wt.%:, Carbon 0.05 - 0.12

Manganese 1,2 - 2,0

20

Silicon0.15 - 0.60

Vanadium 0.04 - 0.12

Niobium 0.01 - 0.08

Molybdenum 0.005 0.13

Aluminum0.01 - 0.06

Nickel0.02 - 0.50

Chrome0.02 - 0.50

Nitrogen0,008 - 0,025

Calcium 0.001 - 0.030

Cerium0.002 - 0.040

IronErest

The disadvantage of this steel is low toughness and cold resistance in the state after controlled rolling.

The purpose of the invention is to increase the toughness and cold resistance of steel in a hot rolled state.

To achieve this goal, steel containing carbon, manganese, silicon, vanadium, niobium, nitrogen, nickel, chromium, aluminum, rare earth metals and iron, additionally contains titanium and copper in the following ratio of components, wt.%:

Carbon0.05-0.15

Manganese 1.2 -2.0

Silicon0.15-0.60

Vanadium 0.03-0.15

Niobium0,005-0,10

0.002-0.015 0.01-0.30 0.01-0.30

0,006-0,06

ny

0.002-0.050 0,, 10 0.01-0.30 Else

As impurities, steel may contain less than 0.01% sulfur and less than 0.02% phosphorus.

In the induction furnace, the following variants of the proposed steel were molded and tested under industrial conditions (Table 1). Casting is carried out according to the usual technology, rolling with the use of controlled rolling modes. The values of toughness, yield strength, temporal resistance, relative elongation and proportion of viscous component in the fractures of specimens are determined by standard methods. The test results are shown in Table. 2

As can be seen from the data presented, the steel proposed has a higher impact strength and cold resistance than is known, in combination with high strength and ductility. Pipes of the proposed steel are welded reliably, because it meets the requirements for welding and has a low carbon equivalent (up to 0.40%).

61

62 64 63

Claims (3)

1. US patent N ° 3788874, cl. 75-124, 1973. 2. Forward Germany No. 2320185, cl. C 22 C 38/04, 38/50, 1977. 3. USSR author's certificate number 625235, cl. C 22 C 38/48, 1979.