SU800226A1 - Steel - Google Patents

Description

(54) STEEL

t

The invention relates to metallurgy, namely, structural steel, used in pipelines, for example, in the manufacture of gas and oil pipelines of large diameter when operating them in conditions of the North.

Known steel f 1), containing, wt.%:

CarbonO8-O, 25

Manganese 0.7-2.0

Silicon0,4-1,0

Nitrogen, OO8-0,05

VanadiyO, 01-O, 25

Niobium, OO5-O, 10

Serado O, O35

Fosfordo O, O35

CeriOO, OO5-O, 2O

Iron Else.

Closest to the proposed technical essence and the achieved effect is steel 2, containing

.

Carbon0, O5-O, 3

Manganese 0.4-3.0

Silicon

0.2-1.5

Vanadium 0.001-0.3

Niobium 0.001-0.2

Nitrogen 0,00 3-0,05

Aluminum 0.001-0.12

Calcium 0,0005-0,005

Magnesium 0.0005-0.005

Iron Else

The disadvantage of this steel is the low values of toughness, on the x) Charpy bits (with a sharp notch), which determines the possibility of using it in conditions of the North.

The purpose of the invention is to increase the toughness of steel with negative

S temperatures down to minus C.

The goal is achieved by the fact that the proposed steel additionally contains molybdenum in the following ratio of components, wt.%;

Carbon 0.14-0.2

Manganese1,2-1,6

Silicon0,3-O, 7

Vanadium0, O5-0,2O

Nitrogen

0.014-0.030

Niobium 0,005-O, O5

Aluminum 0.005-0.04

Calcium 0.005-0.050

Molybdenum 0.01-0.10

Iron Else

The proposed steel has the following

mechanical properties in the state after

normalization;

Z

Tensile strength

64 kg / mm. Yield strength

48 kg / mm Relative elongation 25% 1 0.14 1.6 0.7, 0.20 0.003 0.10 2O, 16 1.3 O, 5 O, O5 0, O2O 0, O5 30.20 1.2 0, 3О, 12 О, 04О О, 01 According to standard methods, the values of strength, strength, strength, strength and toughness are determined.

Proposed

Shock viscosity

four

at 20 C

9 kgm / cm

Sharpie

- -6 kgm / cm

—BJAS4 kgm / cm 2

Under laboratory conditions in an induction furnace, three versions of steel of reduced chemical composition were smelted. Casting and rolling did not require any special technology.

In tab. 1 given the compositions of the proposed steel.

Claims (2)

Table 0, O50 0.027 0.02 0.025 O, OO5 0.025 O, O20 0.02 0.025 0.023 O, O05 0, O15 0.02 O, 025 O, O50 Tab. Figure 2 shows the mechanical properties offered in steel. Table 2 From the comparison of the MexaHH fecKRx properties of the proposed and known steel, it is apparent that the internal viscosity, measured at room temperature and negative temperatures of the present steel, is 3-4 kgm / cm higher than that of the known steel. From this it follows that the proposed steel, in terms of impact strength, meets the requirements that are imposed on it for operation in conditions of the North. The pipes of the proposed steel are welded quite reliably, since it has a low carbon equivalent (O, 46%). The economic effect from the introduction of the proposed steel is 25 thousand rubles. Formula Invention Steel containing carbon, manganese, silicon, vanadium, nitrogen, niobium, aluminum800226 or 5 m to IS M JJ 4 AND, calcium and iron, is different in that with the aim of increasing the aryan viscosity at Negative temperatures, it additionally contains libden in the following ratio of components, wt.%: 0.14-0.20 Carbon 1.2-1.6 Manganese 0.3-0.7 Silicon 0.05-0.20 Vanadium Nitrogen 0 , O14-0, OZO Niobium 0.005-0.05 Aluminum 0.005-0.04 Calcium 0.005-0.050 Molkboen 0.01-0.10 Iron Else Sources of information taken into account when 9xpert ae 1. The author's certificate of the USSR 336367, cl. C 22 C 38/12, 1972. 2. Authors certificate of the USSR 522264. cl. C 22 C 38/12, 1976.