(57) Abstract:The invention relates to metallurgy, and in particular to compositions of steels for pipelines and gas pipelines. The proposed steel that contains components in the following ratio, wt. %: carbon 0.05 to 0.15, silicon 0,30-0,90, manganese 0.40 to-0,90, vanadium 0,05-0,20, niobium 0,01-0,08, aluminum 0,01-0,08, sulfur 0,001-0,020, phosphorus 0,005-0,02, Titan of 0.001 to 0.04, iron - rest. The technical result of the invention is to improve the corrosion resistance and toughness of steel. 3 table. The invention relates to metallurgy, and in particular to compositions of steels for pipelines and gas pipelines.The steel used in the manufacture of pipes for main pipelines, must combine high mechanical and corrosion properties. Technical agreement TC-105-21-98 regulates the following set of properties (table. 1).Known steel  , having the following chemical composition, wt. %:
Carbon - 0,06-0,10
Silicon - 0,17-0,37
Manganese - 1,0-1,6
Molybdenum - 0,3-0,5
Vanadium - 0,05-0,1
Aluminum - 0,02-0,05
Cerium - 0,0005-0,005
Calcium - 0,0005-0,005
Iron - Rest
The disadvantage of steel is the known structural steel of the following chemical composition, wt. %  :
Carbon - 0,15-0,35
Silicon - 0,15-1,0
Manganese - 0,4-1,5
Vanadium - 0,04-0,18
Niobium - 0,008-0,1
Aluminum - 0,02-0,15
REM - 0,002-0,2
Iron - Rest
Known structural steel for corrosion resistance and toughness does not meet the requirements of steels for pipelines and gas pipelines.Most similar in their chemical composition and properties to the proposed steel is steel  containing, by weight. %:
Carbon - 0,08-0,16
Silicon - 0,17-0,37
Manganese - 1,40-1,70
Vanadium - 0,06-0,12
Niobium - 0,06-0,12
Aluminum - 0,015-0.04
Sulfur - 0,015-0,035
Phosphorus - 0,010-0,030
Bor - 0,0008-0,004
Cerium - 0,005-0,01
Iron - Rest (prototype)
Known steel has a low corrosion resistance and toughness.The technical problem solved by the invention is to improve the corrosion resistance and toughness of steel.To solve this technical problem, the steel containing carbon, silicon, manganese, vanadium, niobium, aluminum, sulfur, phosphorus and iron, additionally contains titanium in the following ratio, wt. %:
Carbon - 0,05-0,15
Silicon ->/BR>Phosphorus - 0,005-0,02
Titanium is 0.001-0.04
Iron - Rest
Mapping of known composition became adopted as a prototype  , and proposed shows that the content of carbon, silicon, vanadium, niobium, aluminum, sulfur and phosphorus fully or partially overlapping. The proposed steel further comprises 0.001 to 0.04% of titanium and a smaller amount of manganese. Due to this enhanced corrosion resistance and impact toughness of the steel.The carbon steel of the proposed structure determines its strength. The lower carbon content of less than 0.05% causes a reduction in strength below acceptable levels. The increase of carbon content in excess of 0.15% deteriorates the ductility and toughness of steel.Silicon rascism and strengthens steel, improves its elastic properties. The deoxidation of steel silicon flows through the reaction:
2FeO + Si ---> 2Fe + SiO2.When the silicon content less than 0.3% strength become insufficient. The increase in silicon content higher than 0.9% leads to an increase in the number of silicate inclusions, abruptive steel, impairs its plasticity.Manganese entered for deoxidation and increase the strength of steel. Rascislau action is no place decrease of the strength and viscosity properties. The increase in the content of this element more than 0.90% deteriorates the ductility of the steel to5< 24% , which is unacceptable.Vanadium is carbidopa element in the steel. Crushing the grain, it improves weldability, strength and toughness of steel. When the vanadium content less than 0.05% of its positive effect is not manifested. The increase in the content of vanadium is more than 0.20% were found to be inappropriate, because it does not lead to the improvement of the properties of steel.Niobium is an effective caridovascular, grinding grain microstructure. When the content of niobium, less than 0.01% of the toughness of steel is below acceptable. The increase in the content of niobium more than 0.08% leads to its selection on the grain boundaries in the form of intermetallic compounds. This impairs the properties of the steel.Aluminum is rescission and the modifying element. In addition, it binds to nitrogen in the nitride. When the aluminum content less than 0.01% of its influence slowly, the steel has a low mechanical properties. Increasing the aluminum content more than 0.08% causes graphitization of steel, the loss of strength and deterioration of weldability.Sulfur present in the steel, forming sulfides of manganese. When the content of the series is riodic to increase the threshold jednoralski. The increase in the sulphur content of more than 0.02% affects viscosity, strength and plastic properties of steel below an acceptable level, especially in the direction across the direction of rolling of the strip.Phosphorus in the amount of 0.005-0.02% of the whole dissolves into-the gland that leads to hardening of the metal matrix, the improvement of corrosion resistance of steel. However, the increase in the content of phosphorus more than 0.02% causes embrittlement of steel and the decrease in toughness, which is unacceptable. Reducing the phosphorus content of less than 0,005%, first, impairs corrosion resistance of steel and, secondly, it is not economically feasible.Introduction in this steel titanium increased its corrosion resistance and toughness. When the titanium content less than 0.001% deteriorates corrosion resistance: the rate of General corrosion of steel Q > 0.8 mm/year, CLR > 4, CTP > 6. The increase in the titanium content in excess of 0.10% deteriorates the complex mechanical properties of steel leads to the formation of sub-cortical porosity at the surface of the ingot and the decline in the quality of hot-rolled strips.In table. 2 shows the chemical composition of steels with different alloying elements, and table. 3 - the results of the tests with the higher corrosion resistance and toughness steel suitable for the manufacture of pipes, pipelines and gas pipelines. In cases beyond the contents of the alloying elements (compositions No. 1 and No. 5) corrosion resistance and toughness are reduced. Lower corrosion resistance and toughness has steel-prototype (composition No. 6).Technical appraisal and economic benefits the proposed steel lies in the fact that the additional introduction in its composition of 0.001 to 0.04% titanium regulated when the content of the remaining elements ensures the formation of a favorable microstructure having high corrosion resistance and frictional properties at a regulated combination of strength and ductility. The proposed steel is also characterised by a good weldability. Therefore, it is suitable for the manufacture of oil and gas pipelines, term trouble-free operation of which will be increased.As the base object is selected steel prototype. The use of the proposed steel will increase the profitability of production of electric-welded pipes by 10-15%.Literature
1. The patent of Russian Federation N 2100470, IPC With 22 38/12, 19972. Auth. St. USSR N 753924, IPC With 22 38/12, 1980
vanadium, niobium, aluminum, sulfur, phosphorus and iron, characterized in that it additionally contains titanium in the following ratio, wt. %:
Carbon - 0,05 - 0,15
Silicon - 0,30 - 0,90
Manganese - 0,40 - 0,90
Vanadium - 0,05 - 0,20
Niobium - 0,01 - 0,08
Aluminum - 0,01 - 0,08
Sulfur is 0.001 - 0.020
Phosphorus - 0,005 - 0,02
Titanium is 0.001 - 0.04
Iron - Rest
FIELD: ferrous metallurgy.
SUBSTANCE: invention provides round-profiled iron smelted from alloyed steel composed of, wt %: carbon 0.06-0.11, manganese 0.30-0.9, silicon 0.001-0.15, boron 0.0005-0.0050, vanadium 0.005-0.08, aluminum 0.02-0.06, titanium 0.01-0.04, sulfur 0.005-0.020, nitrogen 0.005-0.015, calcium 0.001-0.010, iron and unavoidable impurities - the balance. When following relationships are fulfilled: Ti/48+Al/27-N/14 ≥ 0.6 x 10-3; Mn+5.0C ≥ 0.80; Ca/S ≥ 0.065, rolled iron has following characteristics: maximum degree of pollution with nonmetal inclusions, in particular sulfides, oxides, silicates, and nitrides, does not exceed 3 points for each type of inclusions; longitudinally uniform spheroidized structure composed of at least 60% grainy perlite; effective grain size 5-10 points; diameter 10-16 mm; carbon-free layer not exceeding 1.0% of diameter; cold setting value at least 1/3 height; throughout hardenability in circles up to 16 mm in diameter; point of maximum load not higher than 500 MPa; relative elongation at least 22%; and relative contraction at least 70%.
EFFECT: ensured optimal conditions for cold die forging of high-strength geometrically complex fastening members and simultaneously improved steel hardenability characteristics.
FIELD: ferrous metallurgy.
SUBSTANCE: invention provides round-profiled iron smelted from low-carbon steel composed of, wt %: carbon 0.17-0.25, manganese 0.30-0.65, silicon 0.01-0.17, sulfur 0.005-0.020, vanadium 0.005-0.07, niobium 0.005-0.02, calcium 0.001-0.010, iron and unavoidable impurities - the balance. When following relationships are fulfilled: 12/C-Mn/0.02 ≥ 27; 0.46 ≥ 6V+8Nb ≥ 0.22; Ca/S ≥ 0.065, rolled iron has following characteristics: maximum degree of pollution with nonmetal inclusions, in particular sulfides, oxides, silicates, and nitrides, does not exceed 3 points for each type of inclusions; longitudinally uniform spheroidized structure composed of at least 80% grainy perlite; effective grain size 5-10 points; diameter 10-25 mm; carbon-free layer not exceeding 1.5% of diameter; cold setting value at least 1/3 height; point of maximum load not higher than 550 MPa; relative elongation at least 20%; and relative contraction at least 60%.
EFFECT: ensured optimal conditions for cold die forging of high-strength geometrically complex fastening members and simultaneously ensured improved characteristics of in-process plasticity and low level of stray hardening.
FIELD: metallurgy; high-titanium-bearing foundry alloy production.
SUBSTANCE: the invention is dealt with the field of metallurgy, in particular, with production of the foundry alloy containing mainly titanium and also a small amount of other useful metals reduced from oxides of a charge together with the basic components of a foundry alloy. The method includes the following stages: after melting-down of the first portion of the charge representing an ilmenite concentrate formed on the rotating melt of the high-titanium-bearing foundry alloy and reduction by titanium and silicon of a part of oxides from the melted portion of ilmenite they use aluminum to reduce all oxides in a cinder melt. The obtained slag is added with the first portion of calcium oxide in the amount ensuring fluidity of the cinder. The second portion of the charge is introduced in the melt in the amount corresponding to the possibility of to reduce oxides by titanium. The produced titanium oxide is merged with the earlier produced cinder. A determined part of the produced melt in conditions of its rotation is poured out through a side tap hole. Using aluminum reduce titanium oxide from the merged cinder and the reduced titanium merge with the rest metal melt. In the formed final cinder enter the second portion of calcium oxide. A part of the produced foundry alloy is poured out through a side tap hole. Then a final cinder is also poured out and they feed a new portion of ilmenite onto the residue of the foundry alloy. The invention allows to reduce at least twice the power input used for reprocessing of the ilmenite concentrate, as in the process of reduction of the metals from oxides there are no endothermic reactions but exothermic reactions; to use ilmenite concentrates with a share of titanium oxide up to 45% and a strong metal reductant - aluminum, and also to realize a progressive technology of the liquid-phase reduction of metals from oxides in conditions of rotation of the melt by an electromagnetic field.
EFFECT: the invention allows to reduce at least twice the power input used for reprocessing of the ilmenite concentrate, to use ilmenite concentrates with a share of titanium oxide up to 45% and a strong metal reductant - aluminum, to realize a progressive technology of the liquid-phase reduction of metals from oxides.
5 cl, 1 ex, 1 dwg
FIELD: metallurgy; production of important rolled stock for oil-well tubing of increased service life.
SUBSTANCE: proposed method includes making steel of definite chemical composition in electric furnace, tapping metal from furnace into ladle, treatment of metal in ladle and teeming steel into ingot molds. Alloying with molybdenum is performed by introducing molybdenum-containing materials into furnace in making steel. After teeming, ingots are rolled, cooled and heated for rolling in preset temperature range and are subjected to preliminary and final deformation; process is completed by final cooling of rolled blanks to surrounding temperature.
EFFECT: improved strength characteristics and cold resistance of metal; enhanced reliability of metal products.
FIELD: metallurgy, in particular structural steel composition.
SUBSTANCE: claimed steel contains (mass %): carbon 0.42-0.54p; silicium 0.15-0.50; manganese 0.90-1.50; niobium 0.01-0.08; molybdenum 0.06-0.20; aluminum 0.005-0.060; titanium 0.019-0.045; sulfur 0.001-0.045; phosphorus 0.001-0.045; nitrogen less than 0.012; chromium, nickel and copper each not more than 0.30, and balance: iron. Steel of present invention is useful in production of pipelines for oil industry operating at temperature from 50°C to -10°C.
EFFECT: steel with optimum combination of strength and viscous properties.
2 tbl, 1 ex
FIELD: metalwork operating in cold climates at static loads.
SUBSTANCE: proposed iron-based cold-resistant alloy includes the following components, mass-%: titanium, 1-2; carbon, 0.009 max; silicon, 0.1 max; aluminum, 0.003 max; copper, 0.03 max; nickel, 0.2 max; the remainder being iron. Proposed alloy possesses high strength at retained ductility; embrittlement of this alloy at cooling to temperature below minus 78°C is excluded; content of carbon is considerably reduced due to increased content of titanium, thus enhancing resistance to cold.
EFFECT: enhanced efficiency; enhanced cold resistance.
1 dwg, 1 tbl
FIELD: ferrous metallurgy; motor-car industry; production of steels intended for manufacture of items of a complex configuration with the help of cold sheet stamping.
SUBSTANCE: the invention is pertaining to the field of ferrous metallurgy and motor-car industry, in particular, to methods of production of steels intended for manufacture by cold sheet stamping of items of a complex configuration, predominantly details for motor cars. The technical problem is to boost steel stamping, to improve the quality of a surface of a steel strip and hence to improve adhesion of a protective cover. The method includes a steel smelting, casting, hot rolling, strips reeling in rolls, a cold rolling, a recrystallization annealing and a temper rolling. The steel contains components in the following ratio (in mass %): Carbon - 0.002 - 0.008, silicon - 0.005-0.025, manganese - 0.05-0,20, phosphorus - 0.005-0.025, sulfur - 0.003-0.012, aluminum - 0.02-0.07, titanium - 0.02-0.05, niobium - 0.001 0.080, iron and imminent impurities - the rest. The hot rolling is completed at the temperature determined from the ratio: Tf.r≥ 7300 / (3.0-Ig [Nb] [C]) - 253, where Tf.r - temperature of the end of the rolling, °C; [Nb] and [C] - the shares of niobium and carbon in the steel accordingly in mass %, and the recrystallization annealing is carried out in a pusher-type furnace at the temperature assigned depending on the contents of niobium in steel according to the equation: Tan= (750+ 1850 [Nb]) ± 20, where Tan - a temperature of the thermal treatment, °C; [Nb] - the contents of niobium in the steel, in mass %.
EFFECT: the invention allows to boost the steel stamping, to improve the quality of the steel strip surface and adhesion of a protective cover.
4 ex, 1 tbl
FIELD: steel making.
SUBSTANCE: invention relates to such type of steel that is employed in welded structures such as gas conduits, petroleum pipelines, as well as in high-pressure vessels. Steel according to invention contains, wt %: C 0.02-0.10, Si up to 0.6, Mn 1.5-2.5, P up to 0.015, S up to 0.003, Ni 0.01-2.0, Mo 0.2-0.6, Nb below 0.010, Ti up to 0.030, Al up to 0.070, N up to 0.0060, Fe and unavoidable impurities - the rest, provided that parameter P = 2.7C+0.4Si+Mn+0.8Cr+0.45(Ni+Cu)+2V+Mo-0.5 is within a range of 1.9 to 3.5. Microstructure of steel is mainly composed of martensite and bainite. Steel sheet is manufactured by heating casting to at least Ac3, subjecting it to hot rolling, and cooling sheet at a rate 1°C/sec to temperature not exceeding 550°C. Sheet is further used to manufacture a tube. When laying multilayer welding joint, energy absorbed in the Charpy impact test at -40°C is at least 200 J.
EFFECT: achieved elongation strength at least 800 MPa.
21 cl, 1 dwg, 9 tbl, 5 ex
FIELD: metallurgy; production of low-alloyed cold-resistant steel for underwater sea gas lines at working pressure up to 19 Mpa working at low temperatures.
SUBSTANCE: proposed method includes production of steel blank, heating it to temperature above As3, deformation in controllable mode at specific reduction processes and at total reduction of 50-60% followed by controllable cooling; proposed steel has the following composition, mass-%: carbon, 0.05-0.9; manganese, 1.25-1.6; silicon, 0.15-0.30; chromium, 0.01-0.1; nickel, 0.3-0.6; molybdenum, 0.10-0.25; vanadium, 0.03-0.10; aluminum, 0.02-0.05; niobium, 0.01-0.06; copper, 0.2-0.4; calcium, 0.001-0.005; sulfur, 0.0005-0.005; phosphorus, 0.005-0.015; the remainder being iron; preliminary deformation of blanks is performed at temperature of 950-850°C at total reduction of 50-60%; then, blank is cooled down to temperature of 820-760°C at rate of cooling of 15°C/s on controllable cooling unit and final deformation is performed additionally at temperature of 770-740°C to required thickness of skelp at total reduction of 60-76%; further cooling is performed at higher rate of 35-55°C/s to temperature of 530-350°C, after which skelp is cooled in jacket to temperature of 150±20°C and then in the air. New stage of the proposed method makes it possible to manufacture tubes of 1067-1420 mm in diameter at thickness of walls of 24-40 mm which are used for sea gas pipe lines working at pressure of up to 19 Mpa.
EFFECT: enhanced strength, ductility and cold resistance; enhanced operational reliability; increased service life.
2 tbl, 1 ex
FIELD: metallurgy, namely cold resistant steels.
SUBSTANCE: cold resistant steel for machines and apparatuses, namely in gas- and oil production industry operating in condition of cold climate. Such steel contains, mass %: carbon, 0.15 - 0.22; manganese, 0.3 - 0.6; silicon, 0.15 - 0.40; vanadium, 0.08 -0.12; titanium, 0.001 - 0.040; niobium, 0.001 - 0.040; aluminum, 0.03 - 0.06; sulfur, 0.010 - 0.020; phosphorus, 0.010 - 0.020; cerium, 0.005 - 0.05; calcium, 0.001 - 0.01; barium, 0.001 - 0.01; iron, the balance.
EFFECT: improved strength and cold resistance of steel.