Steel, product made out of the steel and the method of its manufacture

FIELD: ferrous industry; production of stainless steel of the martensitic-austenitic class.

SUBSTANCE: the invention is pertaining to the field of ferrous industry, to production of stainless steel of the martensitic-austenitic class intended for manufacture of the high-loaded components working on twisting and bending under a dynamic loading in corrosive acid mediums having a high content of salts of alkaline and alkaline-earth metals, salts of nitrogenous acid and sulfuric acid, ions of chlorine and hydrogen sulfide. The steel contains the following ingredients(in mass %): Carbon - 0.005 - 0.07; silicon - no more than 1.0; manganese - no more than 1.8; chrome - 12.5 - 17.0; nickel - 2.0 - 8.0; molybdenum + 3 · tungsten - 0.05 - 5-4.5; nitrogen - 0.005 - 0.15; boron - 0.0001 - 0.01; at least one the following ingredients: aluminum, titanium, niobium, vanadium - 0.01 - 5.0; iron and impurities - the rest. At that Thus (Mo+3·W)≤(kl-Cr·al), where kl=15.9, a1 = 0.87, and alsoNi=k2-a(Cr+Mo+W), wherek2 = 16.25 ± l.5, a2=0.7 ± 0.l. The method of manufacture of the product provides for ingots casting or blanks continuous casting, rolling and thermal treatment. The technical result of the invention is an increased steel plasticity, its corrosion resistance in hydrosulfuric mediums with a simultaneous increase of stability of the steel mechanical properties.

EFFECT: the invention ensures an increased steel plasticity, corrosion resistance in hydrosulfuric mediums, stability of the steel mechanical properties.

25 cl, 2 tbl, 1 ex

 

The invention relates to ferrous metallurgy, in particular, to methods for producing stainless steel products, stainless steel products, as well as stainless steel martensitic-austenitic, which is designed for the production of highly loaded parts operating in torsion and bending under dynamic loading and in aggressive acidic media with a high content of salts of alkaline and alkaline-earth metals, salts of nitric and sulphuric acids, ions of chlorine, hydrogen sulphide.

Known steel of the following composition, in wt.%:

carbon - 0,01-0,07

silicon - 0,4-0,8

manganese - 0,4-0,8

chrome - 15,0-17,0

Nickel - 2,5-4,5

copper - 1,6-3,0

niobium - 0,15-0,35

iron - rest (see EN No. 2215815 C1,10.11.2003,)

The prior art also know the product is made from high-strength corrosion-resistant steel, austenitic-martensitic class, hardening with nitrogen, intended for the production of highly loaded machine parts, in particular of aircraft operating at the temperature of minus 70°to 300°in any climatic conditions (see, for example, RU 2214474 C2, 20.10.2003, 7 With 22 38/48).

A disadvantage of the known steels, as well as products from them is insufficient plasticity, instability patterns of steel in aggressive acidic media, resulting in over time during operation of the mechanical properties of steel products could the t to deteriorate.

The problem solved by the invention is the creation of steel and articles thereof, having high ductility, optimum corrosion resistance, primarily in hydrogen sulfide environments, while enhancing the stability of the mechanical properties of steel during the operation.

The specified task in the part of the steel is solved in that the steel according to the invention contains carbon, silicon, manganese, chromium, Nickel, iron, nitrogen, molybdenum, tungsten, boron and at least one component from the group of: aluminum, titanium, niobium, vanadium in amounts of, in wt.%:

carbon0,005÷0,07
siliconnot more than 1.0
manganesenot more than 1.8
chrome12,5÷17,0
Nickel2,0÷8,0
molybdenum + 3·Wolfram0,05÷4,5
nitrogen0,005÷0,15
Bor0,0001÷0,01
at least one component of
group: aluminum, titanium, niobium, vanadium0,01÷5,0
iron and impuritiesrest

provided that the content of its components satisfies the ratio is the s (Mo+3· W)≤(k1-Cr·a1), where k1=15,9, a1=0,87, and Ni=k2-a2·(Cr+Mo+W), where k2=16,25±1,5, a2=0,7±0,1.

The steel may further contain copper (0,05÷5,0) wt.%.

The steel may contain at least one of the following additional components: calcium, cerium, barium, rare earth metals, zirconium, yttrium, magnesium, arsenic, tantalum, selenium.

Each additional component may be contained in the amount of (0,001÷0,1) wt.%.

The steel may further comprise lanthanum in number (0,005÷0,02) wt.%.

The steel may further contain cobalt in an amount of not more than 1.0 wt.%.

The specified task in terms of method of manufacture of steel products is solved by the fact that according to the invention the product obtained from the above-described steel, and the steel is poured into ingots or continuously cast billets, followed by car with obtaining blanks, mainly of cylindrical form, which is subjected to heat treatment in the following modes: heating and drying at a temperature of (300÷650)°C for 1÷17 hours with subsequent cooling in air or in an environment with high cooling capacity, for example water or oil.

Steel can be melted in the electric arc furnace.

The steel before casting may be subjected to vacuum in the ladle.

Car can be completed in two stages: the first stage on the blooming obtaining blanks, mainly, of square section, and then on the bar mill - on preparations, mainly cylindrical shape.

The side of the billet may be from 80 to 120 mm

The diameter of cylindrical workpieces may be predominantly from 12 mm to 45 mm

After receiving the workpieces, mainly cylindrical shape before heat treatment of the workpiece can be cut-to-length bars can then be landing head in cold or hot condition with subsequent preliminary heat treatment, and after applying thread method knurling or threading receive the product in the form of a bolt or screw.

Or after receiving the workpieces, mainly cylindrical shape before heat treatment of the workpiece can be cut-to-length bars with a preliminary heat treatment followed by the application thread by the method of rolling or cutting with getting the product in the form of studs.

The preliminary heat treatment may be performed in mode: heating up (900-1150)°S, shutter speed 1-100 minutes, cooling in air or in an environment with high cooling capacity, for example water or oil.

Can re-heat treatment with heating and well settled and products at the temperature of (300-650)° C for 2-15 hours with subsequent cooling in air or in an environment with high cooling capacity, for example water or oil.

The specified task is in part the product of the steel is solved due to the fact that the product according to the invention, made of the above-described steel.

The product can be manufactured, mainly in the form of a cylindrical rod shape with a diameter from 12 to 45 mm

The product can be manufactured in the form of a shaft, for example, a submersible pump or separator length up to 8.5 meters.

The roughness of its surface Ramay be not more than 2.5 μm on a reference length of 0.8 mm

The product may have a yield strength of not less than 90 kgf/mm2.

The product may have a deviation from straightness of not more than 0.2 mm in one meter of the product.

The hardness of the product may be 444÷285 HB when the diameter of the imprint 2,9÷3,6 mm

The product may be in the form of the fastening element, e.g., bolt, screw or stud size from M5 to M20.

The technical result is steel, the method of manufacturing steel products, as well as the product itself is made of steel having high ductility, optimum corrosion resistance and durability in aggressive, primarily in hydrogen sulfide environments, while enhancing the stability of the mechanical properties of steel during usage is due to the optimally balanced ratio of components of steel, as well as treatment.

So the molybdenum and tungsten are introduced into the steel within the specified limits with the aim of improving the corrosion resistance, especially to pitingolo corrosion. In this sense, the influence of molybdenum and tungsten equivalent. When the total content of molybdenum +3* tungsten less than 0.05%, the effect of these elements on corrosion resistance is not shown. The increase in the content of molybdenum +3* tungsten more than 4.5% to further improve the corrosion resistance of steel will not. Tungsten has a much higher atomic weight 183.85) compared with molybdenum (at 45.44). In paragraph 6 of the notes to the table 1 GOST 4543-71 the possibility of replacing the items from the calculation of the three weight parts of tungsten per weight part of molybdenum.

Tungsten, due to the larger size of the atom, introduces more distortion in the crystal lattice of iron compared to molybdenum. This can improve the strength properties of steel and from this point of view, the use of tungsten is preferable.

On the other hand, the tungsten and molybdenum expensive items, as well as when alloying with tungsten steel requires three times more than that of molybdenum, the use of tungsten for alloying can lead to a considerable rise in prices of steel.

Aluminum, titanium, niobium, vanadium participate in dispersion hardening steel during heat treatment due to the division of intermetallics of the type Ni 3Me. As these elements are considered equivalent, so when alloying steel can be used one of a group of items or all items.

When the content of these elements is less than 0.02% of additional hardening steel through precipitation hardening is missing.

With the increasing content of these elements of strength characteristics of the steel increases, but decreases the ductility and toughness of steel.

When the content of these elements more than 5%, the ductility of the steel and impact strength becomes low, which may lead to breakage of finished products in the process of operation.

Molybdenum, tungsten and chromium belong to territooriumil elements. While alloying steel Mo, W, Cr at the upper limit of their content of steel can go in the ferritic-austenitic class, instead of a martensitic-austenitic class.

The ratio of (Mo+3W)≤(k1-Cr/a1) restricts the upper limit of the content of Mo and W, depending on the number entered chromium. This excludes the transition began in ferritic-austenitic class.

The second formula Ni=k2-a2(Cr+Mo+W) establishes a relationship between austenitisation element Ni and territooriumil elements Cr, Mo, W. the conditions of the formula also allows obtaining of steel martensitic-austenitic class.

To the ratio k 2has the range of values of k2min=14,75 and k2max=17,75. If the value of the Nickel will be lower than calculated when k2minthe steel acquires a martensitic or martensitic-ferritic structure with reduced plastic properties.

When the Nickel content is more calculated when k2maxsteel turns austrina-martensitic structure containing austenite more than 30%. This results in reduced mechanical properties of steel.

Thus, the Nickel content in the steel depends on the number territooriumil elements and is defined by Ni=k2-a2(Cr+Mo+W), where a2- correction factor.

High strength steel can be provided and martensitic-ferritic steel structure, as, for example, in the steel according to the patent RU 2215815. In this case, when the same chromium content (territooriumil elements) required a lower Nickel content (austintoebosch elements).

At the same time, Nickel - flexible, corrosion-resistant element. Increasing the Nickel content in the steel, giving it great flexibility, which can be characterized by the following parameters: elongation, relative narrowing, toughness, resistance of steel to cyclic fatigue, etc. and also improve corrosion resistance, primarily in hydrogen sulfide environments

Of equal strength due to approximately equal content of martensite. In the first case, as the excess phase contains ferrite, the second austenite.

The carbon in the steel to form chromium carbides, which in the case of the carbon content of more than 0.07% significantly degrade the ductility of the steel and toughness. You must strive for the minimum carbon content. At the same time, obtaining carbon less than 0,005% fraught with technical difficulties and financial costs caused by the use of special methods of steel production and the use of particularly clean charge materials. At the same time, reducing the carbon content of less than 0,005% significantly improve the plastic properties of steel will not.

Silicon and manganese are technological additives used for deoxidation of steel. Their content in the steel to 1.0 wt.% and to 1.8 wt.% accordingly no effect on the service properties of the steel. Higher levels may cause deterioration of the plastic properties.

When the chromium content of less than 12.5% rapidly deteriorating corrosion resistance of steel. When the chromium content of more than 17% in the steel is the formation of additional phase - ferrite. This results in reduced mechanical properties of steel, deteriorating ductility.

The nitrogen in the steel is introduced with the purpose facilities the aqueous hardening steel first of all, due to the formation of nitrides of niobium, titanium, vanadium.

Fine particles of metal nitrides are evenly placed around the grain volume, advanced procrea steel. When the nitrogen content of less than 0,005% additional hardening due to the formation of nitrides will be insignificant. When the nitrogen content exceeding 0.15% along with a significant hardening of steel, will be reduced plastic properties.

The introduction of boron in the steel leads to improved plastic properties, primarily toughness. The selection of borides of metals on borders of grains prevents the release of harmful elements sulfur, phosphorus at the grain boundaries.

The boron doping is less than 0,0001 will not provide a noticeable improvement in the plastic properties. At the same time, when the boron doping in the amount of more than 0.01, the result of the formation of excessive amounts of borides of metals, starts to decrease plastic properties.

The required level of mechanical properties of steel products result of such treatment.

Properties of precipitation hardening steel are determined by the number and dispersion of released intermetallic particles. At a temperature of less than 300°processes are slow. Insufficient removed the source voltage of martensite. As a result, the steel does not acquire rebamol strength, but because notusing martensite in the future when operating products possible breakage.

At temperatures close to, but exceeding 300°With, due to slow processes require significant exposure to 17 hours to get noticeable hardening.

With increasing temperature the intensity of formation of intermetallic particles increases, the steel acquires greater strength. The maximum strength of the steel reaches at 450-500°C. At higher temperatures the intermetallic compounds are highlighted in larger sizes. When this is achieved the strength of the steel is reduced, and minimum required strength is achieved at a temperature not exceeding 650°C.

If the shutter speed is less than 1 hour, the number of intermetallic particles will be insufficient for appreciable hardening steel at all temperatures.

At a speed of more than 17 hours, the growth of spin-off intermetallic particles, resulting in a decrease in the strength of the steel.

Thus, the proposed steel product, and a method of manufacturing steel products provide greater flexibility while maintaining high strength, their stability during operation, as well as resistance to stress corrosion cracking under stress while working in hostile environments.

Example.

Steel was smelted in the main on is the creation of the furnace. Casting was carried out in the bars of 1.15 T. the Ingots were rolled on the blooming on the workpiece - 100 mm square Billets were rolled on the bar mill on the rods with a diameter of 20 mm and a length 5400 mm Heat treatment rods was double the leave on the following modes:

- heating and self-control rods at a temperature of 600°C for 4 hours followed by air cooling;

repeated heating and endurance bars at a temperature of 600°C for 4 hours followed by air cooling.

The finished bars were determined mechanical properties.

Testing of mechanical properties was carried out according to GOST 1497-43, toughness according to GOST 9454-78.

The resistance of steel to stress corrosion cracking under tension in hydrogen sulphide was performed according to the method of NACE standard TM 0177-96 (USA). The sample was placed in an aqueous solution of hydrogen sulfide and it was applied tensile stress, which created tension in the metal, equal to 70% of the steel yield strength. The resistance of steel to stress corrosion cracking under tension in hydrogen sulphide was determined as the time elapsed from the beginning of the test to the complete destruction of the sample. The chemical composition of the steel produced with different content components, the test results of mechanical properties and corrosion tests are given in the table is Zach 1, 2.

td align="center"> 1,2
Table 1

Chemical composition of steel
Option
Chem. composition123456
carbon0,0150,070,0050,0150,0150,015
silicon0,31,00,30,30,30,3
manganese0,40,41,00,40,40,4
chrome151515151517
Nickel*fact52,47,21,96,83
calculation2,1÷6,12,4÷5,44,2÷7,22,1÷6,12,1÷6,12,0÷5,0
molybdenum1,52,550,021,51,5
Wolfram0,10,10,010,10,10,1
molybdenum+3·tungsten*fact1,82,850,051,81,81,5
calculation≤2,85≤2,85≤2,85≤2,85≤2,85≤1,1
nitrogen0,050,150,0050,050,050,05
Bor0,0010,0050,010,0080,0010,0001
aluminum+titanium+niobium+vanadium30,025,0333
*) In table 1 for the specified components in addition to the actual

the contents of the components in the embodiments of the steel composition are estimated

required by the formula of their values.

Table 2

Mechanical and corrosion properties of steel
Option
Properties123456
Limit125120128125100115
fluidity,
kg/mm2
Temporary130127132130110120
resistance
gap
kg/mm2
Relative605860506055
narrowing,%
Relative201820122017
elongation,%
Shock12011012080120100
the viscosity
J/cm2
Corrosion800750800700800760
resistance
steel
voltage
hourȀ

Options 1, 2, 3 correspond to the invention. Option 1 - optimum. Options 4, 5 - does not meet present invention, as the Nickel content beyond the boundaries defined by the formula. In the option 4 has lower values of ductility and corrosion resistance, because the steel was purely martensitic, and option 5 has lower strength properties due to the excessive content of austenite.

Option 6 has a molybdenum content +3* tungsten over a certain formula. Steel has a high content of ferrite and residual austenite and, consequently, reduced strength and plastic characteristics.

1. Steel, characterized in that it contains carbon, silicon, manganese, chromium, Nickel, iron, nitrogen, molybdenum, tungsten, boron and at least one component from the group of: aluminum, titanium, niobium, vanadium in amount, wt.%:

Carbon0,005÷0,07
Siliconnot more than 1.0
Manganesenot more than 1.8
Chrome12,5÷17,0
Nickel2,0÷8,0
Molybdenum + 3·Wolfram0,05÷4,5
Nitrogen0,005÷015
Bor0,0001÷0,01
At least one component from the group of: aluminum, titanium, niobium, vanadium0,01÷5,0
Iron and impuritiesRest

provided that the content of its components satisfies the following relations: (Mo+3·W)≤(k1-Cr·a1), where k1=15,9, a1=0,87, and

Ni=k2-a2·(Cr+Mo+W), where k2=16,25±1,5 and2=0,7±0,1.

2. The steel according to claim 1, characterized in that it additionally contains copper (0,05÷5,0) wt.%.

3. The steel according to claim 1, characterized in that it contains at least one of the following additional components: calcium, cerium, barium, rare earth metals, zirconium, yttrium, magnesium, arsenic, tantalum, selenium.

4. The steel according to claim 3, characterized in that each additional component is contained in an amount of 0.001÷0.1 wt.%.

5. The steel according to claim 1, characterized in that it further comprises lanthanum in an amount of 0.005÷0.02 wt.%.

6. The steel according to claim 1, characterized in that it further contains cobalt in an amount of not more than 1.0 wt.%.

7. A method of manufacturing steel products, characterized in that the product is produced from a steel according to any one of claims 1 to 6, and the steel is poured into ingots or continuously cast billets, followed by Bicycle is in obtaining blanks predominantly cylindrical shape, which is subjected to heat treatment in the following modes: heating and drying at a temperature of 300÷650°for 1-17 hours with subsequent cooling in air or in an environment with high cooling capacity, for example water or oil.

8. The method according to claim 7, characterized in that the steel smelted in electric arc furnace.

9. The method according to claim 7, characterized in that the steel before casting is subjected to vacuum in the ladle.

10. The method according to claim 7, characterized in that the steel is poured into ingots with a mass of 0.7-2.5 tons or continuously cast billets of square or round cross-section with sides of the square or in diameter from 80 to 220 mm

11. The method according to claim 7, characterized in that the rolling is carried out in two stages: the first stage on the blooming obtaining billets mainly of square section, and then on the bar mill - on billet predominantly cylindrical shape.

12. The method according to claim 11, characterized in that the side of the billet is from 80 to 120 mm

13. The method according to claim 11, characterized in that the diameter of cylindrical workpieces is mainly from 12 to 45 mm

14. The method according to claim 7, characterized in that after receiving blanks predominantly cylindrical billets are cut-to-length bars, followed by landing a head cold or hot state from the settlement of etousa preliminary heat treatment, moreover, after applying thread method knurling or threading receive the product in the form of a bolt or screw.

15. The method according to claim 7, characterized in that after receiving blanks predominantly cylindrical billets are cut-to-length bars, then measuring rods are subjected to a preliminary heat treatment followed by the application thread by the method of rolling or cutting with getting the product in the form of studs.

16. The method according to any of PP and 15, characterized in that the preliminary heat treatment is carried out in the following manner: heating to 900-1150°S, shutter speed 1-100 min, cooling in air or in an environment with high cooling capacity, for example water or oil.

17. The method according to claim 7, characterized in that re-produce heat treatment with heating and drying at a temperature of 300-650°during 2-17 h with subsequent cooling in air or in an environment with high cooling capacity, for example water or oil.

18. The product is made of steel, characterized in that it is made of steel according to any one of claims 1 to 6.

19. Product by p, characterized in that it is made mostly in the form of a cylindrical rod shape with a diameter from 12 to 45 mm

20. Product by p, characterized in that it is made in the form of a shaft, such as a submersible pump or separator length up to 8.5 meters

21. Product by p, ex is different, however, the roughness of its surface Ranot more than 2.5 μm on a reference length of 0.8 mm

22. Product by p, characterized in that it has a yield strength of not less than 90 kgf/mm2.

23. Product by p, characterized in that it is the deviation from straightness of not more than 0.2 mm in one meter of the product.

24. Product by p, characterized in that its hardness is 444-285 HB when the diameter of the imprint 2,9÷3,6 mm

25. Product by p, characterized in that it is made in the form of a fastener such as a bolt, screw or stud size from M5 to M20.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: stainless steel comprises, in mass %, 0.01-0.07 of C, 0.3-1.8 of Mn, up to 1.0 of Si, 14-18 of Cr, 2.0-5.0 of Ni, 1.0-4.0 of Cu, 0.01-1.0 of Nb, 0.01-0.12 of N, 0.01-2 of AL+Ti, Fe, and accompanying admixtures the remainder. At least one of the components (aluminum or titanium) forms intermetallic compounds with nickel.

EFFECT: enhanced strength and resistance to corrosion.

9 cl, 1 dwg, 1 tbl

FIELD: powder metallurgy; die-casting.

SUBSTANCE: the invention is pertaining to the field of powder metallurgy, in particular, to a powder mass for die-casting and may be used for production of hardware products for construction. The powder mass for die-casting contains a metallic powder and a thermoplastic binding agent. In the capacity of the metallic powder it contains an austenitic steel with the low contents of nickel or a preproduct of the steel, free of nitrogen or with the low contents of nitrogen, or a mixture of components of the steel or its preproduct. The steel contains (in mass %): carbon - 0.11-0.7; silicon - no more than 2; manganese - no more than 17; chrome - 21-26; nickel - 0-2; molybdenum - no more than 1.5; tungsten - no more than 2; copper - no more than 4, in particular, - no more than 2.5; nitrogen - 0.7-1.7; iron and the imminent impurities - the rest. The technical result is increased corrosion resistance and strength.

EFFECT: the invention ensures increased corrosion resistance and strength of produced hardware products for construction.

3 cl, 1 dwg, 3 ex

FIELD: iron and steel industry; production of structural steels for nuclear-power engineering.

SUBSTANCE: the invention is pertaining to the field of production of structural steels for nuclear-power engineering used at production of container equipment for storing and transportation of the waste nuclear fuel and the radioactive waste. The offered cold-resistant steel for load-bearing elements of the metal-concrete containers contains (in mass %): carbon - 0.03-0.10; silicon - 0.3-0.7; manganese - 1.0-1.7; chromium - 0.1-0.25; nickel - 0.1-0.25; copper - 0.1-025; molybdenum - 0.05-0.2; titanium - 0.01-0.1; nitrogen - 0.01-0.05; cerium - 0.01-0.08; sulfur - 0.005-0.015; phosphorus - 0.005-0.015; iron - the rest At that. Thus the total share of carbon and nitrogen does not exceed 0.12 mass %, and sulfur and phosphorus - no more than 0.020 mass %. The technical result is an increased operational reliability and environmental safety of the container assemblies at transportation and a prolonged storage up to 100 years of the waste nuclear materials and the radioactive waste.

EFFECT: the invention ensures an increased operational reliability and environmental safety of the container assemblies at transportation and a prolonged storage up to 100 years of the waste nuclear materials and the radioactive waste.

2 tbl

Rail steel // 2259418

FIELD: ferrous metallurgy; production of rail steel.

SUBSTANCE: the invention is pertaining to the field of ferrous metallurgy, in particular, to production of steel for manufacture of railway rails. The offered rail steel contains its components in the following ratio (in mass %): carbon - 0.32-0.45; silicon - 0.95-1.20; manganese - 1.25-1.5; chromium - 0.8-1.0; vanadium - 0.09-0.15; aluminum - no more than 0.005; nitrogen - 0.012-0.02; calcium - 0.0005-0.049; molybdenum - 0.2-0.5; niobium - 0.003-0.02; nickel - 0.05-0.3; iron - the rest. At that in capacity of the impurities the steel may contain (in mass %): sulfur - no more than 0,015; phosphorus no more than 0,02; copper no more than 0.2. The technical result of the invention is an increased complex of the rail steel mechanical properties and firmness of the rails, and also increased their operational durability.

EFFECT: the invention ensures an increased complex of the rail steel mechanical properties and firmness of the rails as well as an increase of their operational durability.

2 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

Rail steel // 2256000

FIELD: ferrous metallurgy; production of steel of railway rails.

SUBSTANCE: proposed steel contains the following components, mass-%: carbon, 0.30-0.35; silicon,1.15-1.25; manganese, 1.50-2.60; chromium, 0.6-1.3; vanadium, 0.08-0.15; aluminum, 0.005-0.010; nitrogen, 0.012-0.020; calcium, 0.001-0.020; molybdenum, 0.10-0.40; strontium, 0.001-0.020; nickel, 0.001-0.30; the remainder being iron. Proposed steel contains limited amount of admixtures, mass-%: sulfur, no more than 0.020; phosphorus, no more than 0.020; copper, no more than 0.20.

EFFECT: improved mechanical properties and hardness of steel; increased service resistance of rails.

2 cl, 2 tbl

Low-alloy steel // 2255999

FIELD: metallurgy; structural welding steels used for manufacture of side members for heavy-duty automobiles working in Extreme North.

SUBSTANCE: proposed low-alloy steel contains the following components, mass-%: carbon, 0.08-0.15; silicon, 0.1-0.6; manganese, 1.0-1.8; chromium, 0.3-0.9; copper 0.1-0.5; vanadium, 0.02-0.1;maluminum, 0.01-0.06; nickel, 0.7-1.5; nitrogen, 0.002-0.015; calcium, 0.002-0/030; niobium, 0.01-0.05; titanium, 0.004-0.035; sulfur, no more than 0.010; phosphorus, no more than 0.020; the remainder being iron.

EFFECT: increase of impact viscosity to 44 J/cm2 at temperature of 70°C at retained weldability.

3 tbl

FIELD: metallurgy; rolling process; manufacture of electrically welded pipes for erection of oil and gas lines in northern latitudes.

SUBSTANCE: proposed method includes heating the slabs to temperature of 1160-1190°C and performing finish rolling at total relative reduction of no less than 70% at temperature of end of rolling not above 820°C. Besides that, skelps are heated to temperature of 900-950°C after rolling and are subjected to water hardening; then skelps are tempered at temperature of 600-730°C. Skelps are rolled from low-alloyed steel having the following composition, mass-%: C, 0.07-0.12; Mn, 1.4-1.7; Si, 015-0.50; V, 0.06-0.12; Nb,0.03-0.05; Ti, 0.010-0.030; Al, 0.02-0.05; Cr, no more than 0.3; Ni, no more than 0.3; Cu, no more than 0.3; S, no more than 0.005; P, no more than 0.015; N, no more than 0.010; the remainder being Fe.

EFFECT: improved mechanical properties, weldability; increased yield of good skelps.

3 cl, 3 tbl, 1 ex

FIELD: metallurgy, in particular chromium-nickel-manganese-copper austenite stainless steel.

SUBSTANCE: claimed steel contains (mass %) (a) C 0.03-0.12; (b) Si 0.2-1.0; (c) Mn 7.5-10.5; (d) Cr 14.0-16.0; (e) Ni 1.0-5.0; (f) N 0.04-0.25; (g) Cu 1.0-3.5; (h) Mo as trace element; and balance: Fe and inevitable impurities. Austenite stainless steel contains less, than 8.5 vol.% of δ-ferrite, determined as δ-ferrite = 6.77[(d)+(h)+1.5(b)]-4.85[(e)+30(a)+30(f)+0.5(c)+0.3(g)]-52.75.

EFFECT: austenite stainless steel of improved mechanical strength, high corrosion resistance, in particular in salt mist, and high phase stability during hot and cold treatment.

4 cl, 1 dwg, 4 tbl, 22 ex

FIELD: material for glass industry, in particular forming material for machinery pressurized glasses.

SUBSTANCE: claimed material contains (wt. %) carbon 0.01-0.25; silicium 0.35-2.5; manganese 0.4-4.3; chromium 16.0-28.0; nickel 15.0-36.0; nitrogen 0/01-0/29; molybdenum at most 1; oxygen not more than 0.05; phosphorus not more than 0.03; sulfur not more than 0.03; and balance: iron, provided that Ni >= Cr+1.5xSi-0.12xMn-18xN-30xC-6. Material of the present invention has hardness 230-300 HB and high oxidation resistance up to 7500C.

EFFECT: material of high reactionlessness.

11 cl, 2 dwg

FIELD: metallurgy.

SUBSTANCE: stainless steel comprises, in mass %, 0.01-0.07 of C, 0.3-1.8 of Mn, up to 1.0 of Si, 14-18 of Cr, 2.0-5.0 of Ni, 1.0-4.0 of Cu, 0.01-1.0 of Nb, 0.01-0.12 of N, 0.01-2 of AL+Ti, Fe, and accompanying admixtures the remainder. At least one of the components (aluminum or titanium) forms intermetallic compounds with nickel.

EFFECT: enhanced strength and resistance to corrosion.

9 cl, 1 dwg, 1 tbl

FIELD: steel making.

SUBSTANCE: invention relates to steels for pipe-welding industry, whose produce is appropriate in food-processing industry, chemical industry, agriculture, and motor car construction, for example in manufacture of teet cup cartridges and automotive muffler parts. Steel contains following components, wt %: carbon 0.01-0.05, silicon 0.01-0.8. manganese 0.1-0.8. chromium 13.0-18.0, titanium 0.05-0.5, aluminum 0.01-0.1, calcium 0.001-0.02, zirconium 0.005-0.035, nitrogen 0.001-0.025, boron 0.0003-0.005, barium 0.001-0.1, magnesium 0.001-0.02, rare-earth metals 0.001-0.05, nickel 0.1-0.95, vanadium 0.01-0.35, molybdenum 0.01-0.5, tungsten 0.01-0.3, and iron - the balance.

EFFECT: increased plasticity and yield limit thereby contributing to increased pipe-welding productivity.

2 tbl

FIELD: ferrous metallurgy.

SUBSTANCE: invention provides round-profiled iron smelted from alloyed steel composed of, wt %: carbon 0.28-0.35, manganese 0.90-1.40, silicon 0.001-0.37, sulfur 0.005-0.020, chromium 0.001-0.35, vanadium 0.001-0.07, molybdenum 0.001-0.10, nickel 0.001-0.10, niobium 0.005-0.02, titanium 0.01-0.04, boron 0.0005-0.0050, aluminum 0.02-0.06, nitrogen 0.005-0.015, iron and unavoidable impurities - the balance. When following relationships are fulfilled: 12/C-Mn/0.055 ≤ 2.0; 500(Ti/24-N/7)+0.2 ≥ 0; 40 ≥ C/0.01+B/0.001 ≥ 0.33, 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% perlite; effective grain size 5-10 points; diameter of wire 10-25 mm; carbon-free layer not exceeding 1.5% diameter; cold setting value at least 1/3 height; throughout hardenability in circles up to 23 mm in diameter; point of maximum load not higher than 640 MPa; relative elongation at least 18%; and relative contraction at least 55%.

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 steel containing carbon and alloying elements, having specified parameters of metallurgical quality, structure, mechanical properties, hardenability, and in-process plasticity and characterized by being composed of, wt %: carbon 0.17-0.25, manganese 0.90-1.40, silicon 0.01-0.17, sulfur 0.005-0.020, chromium 0.001-0.35, vanadium 0.001-0.07, nickel 0.001-0.10, copper 0.001-0.10, molybdenum 0.001-0.10, titanium 0.01-0.04, boron 0.0005-0.0050, calcium 0.001-0.010, iron and unavoidable impurities - the balance. When following relationships are fulfilled: 22 ≤ 12/C-Mn/0.055 ≤ 47Ni/10Ti+Al ≤ 0.039; 10B-0.01C/N ≥ 1.80, 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% perlite; effective grain size 5-10 points; diameter of wire 10-25 mm; carbon-free layer not exceeding 1.5% diameter; cold setting value at least 1/3 height; throughout (90%) hardenability in circles up to 19 mm in diameter; point of maximum load not higher than 580 MPa; relative elongation at least 18%; and relative contraction at least 60%.

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 steel containing, wt %: carbon 0.10-0.15, manganese 0.90-1.40, silicon 0.001-0.37, sulfur 0.005-0.020, chromium 0.001-0.35, nickel 0.005-0.10, niobium 0,005-0.02, titanium 0.01-0.04, boron 0.0005-0.0050, aluminum 0.02-0.06, nitrogen 0.005-0.015, iron and unavoidable impurities - the balance. When following relationships are fulfilled: 500(Ti/24-N/7)+0.2 ≥ 0; 40 ≥ C/0.01+B/0.0001 ≥ 3.0, 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% perlite; effective grain size 5-10 points; diameter of wire 10-23 mm; carbon-free layer not exceeding 2.5% diameter; cold setting value at least 1/3 height; throughout hardenability in circles up to 15 mm in diameter; point of maximum load not higher than 520 MPa; relative elongation at least 20%; and relative contraction at least 65%.

EFFECT: ensured optimal conditions for cold die forging of high-strength geometrically complex fastening members and simultaneously improved steel hardenability characteristics.

FIELD: metallurgy, in particular composition of dispersion-hardening martensite stainless steel for air-spaceships.

SUBSTANCE: claimed steel contains (mass %) carbon ≤0.030; manganese ≤0.050; silicium ≤1/00; phosphorus ≤ 0.030; sulfur 0.007-0.015; chromium 14.00-15.50; nickel 3.50-5.50; molybdenum ≤1.00; copper 2.50-4.50; niobium + tantalum = (carbon content)x5-0.25; aluminum ≤0.05; boron ≤0.010; nitrogen ≤0.030; and balance: iron and inevitable impurities.

EFFECT: steel excellent in workability.

21 cl, 14 tbl, 2 ex

Steel // 2243288
The invention relates to metallurgy, in particular to low-alloy plate welded structural steels intended for the manufacture of platforms, heavy-duty trucks operating in the Far North

Steel // 2243287
The invention relates to metallurgy, and in particular to compositions of steels used in the production of cold rolled strips, tapes and sheets intended for the manufacture of articles by deep drawing

Rail steel // 2241779
The invention relates to ferrous metallurgy, in particular to the production of steel for rails

The invention relates to nuclear engineering, in particular to designs of fuel elements for fast reactors with liquid metal coolant

FIELD: ferrous metallurgy; production of the corrosion-resistant steel and products made out of it.

SUBSTANCE: the invention is pertaining to the field of ferrous metallurgy, in particular, to production of the corrosion-resistant stainless steel of the martensitic- austenitic class intended for manufacture of the high-loaded component parts working on torsion and bending under a dynamic loading in corrosive acidic mediums with the high content of salts of alkaline and earth metals, salts of nitrogenous and sulfuric acids, ions of chlorine, hydrogen sulfide. The corrosion-resistant steel contains ingredients in the following ratio (in mass %): Carbon - no more than 0.07; chrome - 12.5-17.0; nickel - 2.0-8.0; molybdenum +3 x tungsten - 0.05-4.5; iron and impurities - the rest. At that (Mo+3·W)≤(k1- Cr·a1), where k1=15.9, a1=0.87, and also Ni=k2-a2 (Cr+Mo+W), wherek2=16.25±l.5, a2=0.7±0.1. The technical result of the invention is an increase of pliability, optimal corrosion resistance and strength in the hydrosulfuric mediums with a simultaneous increase of stability of the steel mechanical properties.

EFFECT: the invention ensures an increase of pliability, optimal corrosion resistance and strength in the hydrosulfuric mediums with a simultaneous increase of stability of the steel mechanical properties.

25 cl, 2 tbl, 1 ex

Up!