Steel and its variants

 

(57) Abstract:

The invention relates to metallurgy, in particular to the composition of steel for pump rods, made from a rod of 0.16-40 mm, heat-treated while cooling directly with the temperature of the hot rolling. We offer steel provides high strength in the blanks, heat-treated while cooling with temperatures rolling heat without cracking voltage. The steel composition contains in the following ratio, wt. %: carbon 0.08 to 0.14, manganese 0,9-1,6, chrome 2,0-3,2, vanadium 0.05 to 0.3, the nitrogen 0,006-0,10, iron - rest; the ratio of carbon content to the content of vanadium should be in the range of 0.4 to 2.4. Option steel containing components in the following ratio, wt.%: carbon 0.08 to 0.14, manganese 0,9-1,6, chrome 2,0-3,2, vanadium 0,05-0,30, niobium, not more than 0.02, nitrogen 0,006-0,10, iron - rest; the ratio of carbon content to the content of vanadium should be in the range of 0.4 to 2.4; and the content of vanadium and niobium must satisfy the condition: 10 niobium+vanadium = 0,05-0,30. 2 S. p. f-crystals, 2 tab.

The invention relates to metallurgy, in particular to the development of the composition of steel for pump rods, made from a rod with a diameter of 16-40 m is known steel (ed. St. N 206113) of the following composition, C 0,15-0,22; Mn of 1.2-1.6; Cr 2,5-3,2; V 0.15 to 0.3; Fe rest. This steel will not provide hardening (heat strengthening) rod cooling air directly from the rolling temperatures.

Also known steel (R j N 11, 1985) of the following composition, C 0,15-0,4; Mn 0.5 to 1.5; Cr 1,0-3,0; V 0.05 to 0.15; N 0,006-a 0.02; Fe rest.

Steel of such composition, when the content of carbon and alloying on the lower limit is not quenched by cooling in air, and when the content of carbon and alloying at the upper limit of the tempering air with rolling heating leads to the formation of the rods or tension cracks.

Closest to the proposed steel on the principle alloying and purpose is steel MOI (patent N 58197), C 0,06-0,17; Mn 1,3-3,0; Cr 2,0-4,0; Al 0,01-0,1; Mo 0.2 to 0.5; Fe rest.

The practice of using this steel for the manufacture of rods shows that the rental of steel with carbon content and alloying elements on the lower limit is not quenched by cooling in air from the rolling heat: formed structure of martensite to ferrite, which does not provide the required mechanical properties. Steel with alloying elements and carbon on the upper limit provides high prokalivaem the receiving 16-40 mm speed air cooling too high and leads to the formation of tension cracks.

The development task was the creation of low-alloy steel, which would provide hardenability air bars section 16-60 mm and eliminated the cracking stress.

This technical result is achieved in two ways:

1. Steel containing carbon, manganese, chromium, iron, characterized in that it further comprises vanadium and nitrogen in the following ratio, wt.

Carbon 0.08 to 0.14

Manganese 0,9-1,6

Chrome 2,0-3,2

Vanadium 0,05-0,3

Nitrogen 0,006-0,10

Iron Rest

in this respect, the carbon content of vanadium should be in the range of 0.4 to 2.4;

2. Steel containing carbon, manganese, chromium, iron, characterized in that it further comprises vanadium, nitrogen, niobium in the following ratio, wt.

Carbon 0.08 to 0.14

Manganese 0,9-1,6

Chrome 2,0-3,0

Vanadium 0,05-0,3

Nitrogen 0,006-0,10

Niobium, Not more than 0.02

Iron Rest

thus the ratio of carbon to vanadium is in the range of 0.4 to 2.4: the content of vanadium and niobium satises: 10Nb+V 0,05-0,30.

The basic principle alloying of steel in both cases is the same: a joint introduction to descopera and niobium (2nd option) increases the stability of austenite in the region of normal gamma-alpha transformation and increases the temperature of martensitic transformation in low carbon alloyed austenite. In the air cooling provides in the blanks of these steels education structure of martensite with the strength BV 900-1000 MPa, i.e. steel thermoprocess air cooling directly with temperature rolling heat. Restriction limits the relationship of the content of the carbon content of vanadium defines becoming ensuring hardenability and the absence of cracks in the cooling of the billet cross-section up to 60 mm Condition limiting the total content 10Nb(% )+V(% ) 0,05-0,30 steel 2nd composition option saves expensive alloying elements while providing the optimal sequestration of carbon in austenite and fineness.

The limitation in comparison with the prototype, the carbon content of 0.08 to 0.14% in the proposed steels specified in connection with the need to ensure hardening of the car in the air and the introduction of steel carbidopa elements vanadium and niobium linking of the carbon.

The reduction in the content of manganese and chromium, in comparison with the prototype, due to the need of the economy while ensuring hardenability blanks section 16-60 mm and exceptions tension cracks in the process of martensitic transformation: more alloyed martensite "ptx2">

Chromium and manganese in excess of 3.2% and 1.6% respectively, contributing in the event of liquidation of carbon cracking voltage, because alloyed austenite has a higher coefficient of volume expansion during martensitic transformation.

The exception scarce Mo of the composition of steel reduces the cost of steel vanadium (1st option) and vanadium and niobium (2nd option) associate of the carbon and provide low carbon doped austenite, tempered in the air with the formation of martensite.

Introduction to steel together with the nitrogen nitride and carbidopa elements: vanadium and chrome allows you to have a fine grain steel with high-temperature heating to 1100oC, which increases the impact strength and otpuskarskite in the precipitation hardening.

This ensures the workability of steel at the hot pressure treatment. The ability to obtain fine grains during high-temperature heating and high procedimenti allows you to combine the operations of hot forming and quenching in air, the result can be obtained heat-treated car for the manufacture of rods.

When the content in the Sri nitrogen 0.10% decreases the ductility and toughness of steel.

Thus, given the composition of the steels will provide training on the air billet cross-section 16-60 mm without tension cracks and tensile strength in1000-800 MPa in the absence of deficient molybdenum.

Introduction niobium in the 2nd version of the proposed composition of steel to save expensive vanadium, because the effectiveness of niobium in the interaction with carbon higher than that of vanadium.

Comparison of essential features of the compositions of the steel prototype and proposed structures shows that the proposed formulations have novelty by the following features:

in the prototype, a wide range of carbon content of 0.11% in the proposed formulations interval carbon content is limited to 0.06% taking into account the binding part of the carbon in the austenite in spectrobid vanadium and niobium and produce quenching in air low carbon martensite with strengthin1000-800 MPa;

the limit values of carbon content to the vanadium content of 0.4 to 2.4 provides obtaining the necessary properties as a result of hardening in the air without tension cracks;

the limit of the total content of niobium and vanadium in the steel 2nd option saves you the expensive alloying elements when obesite contains scarce molybdenum, in the proposed composition of molybdenum no: 1 t offer steels cheaper steel prototype at 980-1000 thousand rubles (price alloying molybdenum).

Relevance of the proposed solutions to the criterion: an inventive step is confirmed by the absence of information in the scientific, technical and patent information information about low-alloy steel, which when quenched in air in the blanks section 16-60 mm strengthin1000-800 MPa in the absence of tension cracks.

Example. Steel is known and proposed compositions were melted in an induction furnace, poured into ingots weighing 50 kg, forged in the bars section 100x100 mm and rolled in the bars section 30x30 mm Temperature under hot pressure treatment 1100-1220 C. After the hot forming of the workpiece was cooled in air. Hardenability was evaluated on the billet cross-section 100x100 mm to change the hardness of the section and the emergence of the ferrite in the structure.

Mechanical properties were determined on the rods section 30x30 mm after quenching in air.

Chemical composition and hardenability known and offer steels are given in table. 1, the mechanical properties in table. 2.

Given that the influence of nitrogen and SRO is Ergani other alloying elements. Heat 1 (1st version) had a composition with a minimum content of chromium, manganese and carbon, and the ratio of carbon content to the content of vanadium C/V below specified in the proposed structure. Fusion 13 (1st version) had a ratio of carbon content to the content of vanadium over stated. Fusion 7 (2nd version) had the composition with maximum concentrations of chromium, manganese and carbon; the ratio of carbon content to the content of vanadium C/V is set slightly higher than the proposed structure. Fusion 15 (2nd version) had a total content of niobium and vanadium higher offer, and the ratio of carbon content to the content of vanadium is lower offer. Melt 3 and 4 (2nd option) differed significantly only carbon content.

The results are shown in table. 1 and 2 show that the proposed steel composition under the conditions shown in the formula, provides hardenability air billets with a diameter of less than 60 mm and the desired mechanical properties in the absence of cracks. The cost offered are lower than known.

1. Steel containing carbon, manganese, chromium, iron, characterized in that it further comprises vanadium and nitrogen when the following zootoxin 0,006 0,10

Iron Rest

the ratio of carbon content to the content of vanadium should be in the range of 0.4 to 2.4.

2. Steel containing carbon, manganese, chromium, iron, characterized in that it further comprises vanadium, nitrogen, niobium in the following ratio, wt.

Carbon 0,08 0,14

Manganese 0,9 1,6

Chrome 2,0 3,2

Vanadium 0,05 0,30

Niobium, Not more than 0.02

Nitrogen 0,006 0,1

Iron Rest

the ratio of carbon content to the content of vanadium should be in the range of 0.4 to 2.4, and the content of vanadium and niobium must satisfy the condition 10 niobium + vanadium of 0.05 to 0.3.

 

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Rail steel // 2259416

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 - 0.83-0.5; manganese - 0.6-1.1; silicon - 0.3-0.7; vanadium - 0.08-0.15; aluminum - no more than 0.005; nitrogen - 0.012-0.02; calcium -0.0005-0.005; chromium - 0.05-0.5; one of the devices sampled from a group including zirconium and REM, namely, zirconium -0.0005-0.005; REM - 0.0005-0.005; molybdenum - 0.11-0.3; nickel - 0.05-0.3, iron and impurities - the rest. The technical result of the invention is an increased complex of mechanical properties, firmness of steel and its resistance to brittle fracture, which improves operational stability of the rails. Out of the steel of a stated composition it is possible to manufacture the rails hardened both in oil and in a compressed air with a troostite structure.

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2 tbl

Low-alloyed steel // 2283362

FIELD: metallurgy; making of low-alloy steels for manufacture of articles operating in aggressive media containing hydrogen sulfide and carbon dioxide.

SUBSTANCE: proposed low-alloyed steel contains the following components, mass-%: carbon, 0.05-0.15; manganese, 0.40-0.65; chromium, 0.50-0.80; silicon, 0.30-0.80; vanadium, 0.04-0.09; aluminum, 0.02-0.05; the remainder being iron and admixtures. Content of admixtures is limited as follows, mass-%: nitrogen, no more than 0.008; nickel, no more than 0.30; copper, no more than 0.25; hydrogen, no more than 0.0002; total calcium/sulfur ratio shall be no less than 1. In particular case, proposed steel may contain titanium and niobium; total amount of vanadium, titanium and niobium shall not exceed 0.15 mass-%. Proposed steel may be used for manufacture of pipes and joints for handling aggressive media, watery oil and formation water in particular characterized by high degree of mineralization and containing H2S and CO2.

EFFECT: enhanced strength characteristics and corrosion resistance.

2 cl, 4 tbl

FIELD: metallurgy; production of merchant shapes for manufacture of spherical pins, end-pieces of rods and spherical supports for automobile suspensions.

SUBSTANCE: merchant shapes are molten from steel containing the following components, mass-%: carbon, 0.35-0.42; manganese, 0.50-0.80; silicon, 0.17-0.37; chromium, 0.80-1.10; sulfur, 0.020-0.040; vanadium, 0.005-0.020; calcium, 0.001-0.010; oxygen, 0.001-0.015; nickel, up to 0.25; copper, no more than 0.25; molybdenum, no more than 0.10; arsenic, no more than 0.08; nitrogen, no more than 0.015; the remainder being iron and unavoidable admixtures at oxygen-to-calcium ratio equal to 1-4.5 and calcium-to-sulfur ratio ≥0.065. Proposed merchant shapes contains nonmetallic inclusions of sulfide having double-layer structure; maximum contamination with nonmetallic inclusions pertaining to sulfides, oxides, silicates and nitrides does not exceed 3 points; it contains also structure consisting of 80% of granular pearlite; size of actual grain is 5-10 points at diameter ranging from 10 to 30 mm; provision is made for decarbonized layer not exceeding 1.5% of diameter, magnitude of cold upsetting is no less than 1/3 of height, rupture strength does not exceed 600 Mpa; relative elongation is no less than 18% and relative reduction in area is no less than 60%.

EFFECT: enhanced machinability at full hardenability of shapes up to 30 mm in diameter; retaining of technological ductility of steel.

1 ex

FIELD: metallurgy; production of round bars used for manufacture of shock absorber rods.

SUBSTANCE: proposed method includes melting steel in electric furnace, off-furnace treatment, pouring into ingot molds at protection of jet, hot rolling of ingot, thus obtaining billet followed by rolling, controlled cooling and winding bars in bundles, calibration of bars at deformation degree of 20-25%, unwinding of bars, cutting and straightening and special treatment of surface. Steel contains the following components, mass-%: carbon, 0.40-0.52; manganese, 0.40-0.95; silicon, 0.17-0.37; chromium,, 0.01-0.25; sulfur, 0.020-0.045; vanadium, 0.005-0.020; aluminum, 0.03-0.050; calcium, 0.001-0.010; nitrogen, 0.005-0.015; nickel, up to 0.25; copper, no more than 0.25; molybdenum, no more than 0.10; arsenic, no more than 0.08; phosphorus, no more than 0.030; the remainder being iron and unavoidable admixtures. Calcium-to-sulfur ratio is ≥0.065; hot rolling of merchant shaped is completed at temperature of 1000-1050°C followed by fast cooling to 880-900°C and cooling in air to 300°C. Length of bars from bundle of hot-rolled shapes reaches 6 m at accuracy of cutting of ±5 mm. Finishing of shapes includes trimming, check of surfaces for flaws and ultrasonic monitoring of internal defects, selective dressing.

EFFECT: enhanced machinability of merchant shapes; enhanced ductility and toughness.

1 ex

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FIELD: ferrous metallurgy.

SUBSTANCE: invention relates to steel used in making railways. Invention proposes steel comprising the following components, wt.-%: carbon, 0.71-0.82; manganese, 0.75-1.10; silicon, 0.40-0.60; chrome, 0.70-1.20; aluminum, 0.005, not above, vanadium, 0.05-0.15; calcium, 0.0001-0.005; nitrogen, 0.005-0.015; nickel, 0.03-0.20; barium, 0.0001-0.005; strontium, 0.0001-0.005, and iron, the balance. As impurities steel can comprise, %, sulfur, 0.02, not above; phosphorus, 0.025, not above, and copper, 0.15, not above. Invention provides enhancing complex of physical-mechanical properties and exploitation strength of steel.

EFFECT: improved and valuable properties of steel.

2 tbl

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SUBSTANCE: rolled calibrated round rods are melted from medium-carbon micro-alloy steel containing next ingredients, mass %: carbon, 0.40 - 0.52; manganese, 0.40 - 0.95; silicon, 0.17 - 0.37; chrome, 0.01 - 0.025; sulfur, 0.020 - 0.045; vanadium, 0.005 - 0.02; aluminum, 0.03 - 0.05; calcium, 0.001 - 0.010; nitrogen, 0.005 - 0.015, nickel, no more than 0.25; copper, no more than 0.25; molybdenum, no more than 0.10; arsenic, no more than 0.08; phosphorus, no more than 0.030; iron and inevitable impurities, the balance while next relation is satisfied: calcium/sulfur is equal to 0.065 or more. Rolled piece has lamella type ferrite-pearlite structure with real size of grain 5 - 8 points and with diameter of rolled piece 10 - 30 mm. It has decarburated layer (ferrite + transition zone) consisting of no more than 1,5% of rod diameter, hardness of blank 229 - 255, temporary tensile strength no less than 640 MPa, percentage elongation no less than 6%, percentage narrowing no less than 30 %. Invention provides through calcination of rolled bars with diameter up to 30 mm.

EFFECT: improved cutting capability of steel at favorable relation of strength, ductility and viscosity, minimum anisotropy of mechanical properties at enhanced characteristics of calcination capability.

1 ex

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EFFECT: increased strength of steel, increased useful life period of tool.

1 tbl, 1 ex

FIELD: machine engineering, possibly manufacture of different types of cutters, milling cutters, drills, screw taps and so on.

SUBSTANCE: tool is made of high speed steel P6M5 containing as main strutural component ferrite a-Fe alloyed with chrome, tungsten and molybdenum. Mean size of a-Fe blocks is no more than 47 nm; micro-deformations of crystal lattice of a-Fe are no more than 5.2 x10-3. Invention provides improved strength and lowered embrittlement of ferrite a-Fe.

EFFECT: increased useful life period of tool.

1 tbl

Tool made of steel // 2306207

FIELD: machine engineering, possibly manufacture of different types of cutters, milling cutters, drills, screw taps and so on.

SUBSTANCE: tool is made of steel containing as main structural component ferrite a-Fe alloyed with chrome and molybdenum. Mean size of a-Fe blocks is no more than 35 nm; micro-deformations of crystal lattice of a-Fe are no more than 4.3 x 10-3. Invention provides increased strength and lowered embrittlement of ferrite a-Fe.

EFFECT: increased useful life period of tool.

1 tbl, 1 ex

FIELD: machine engineering, possibly cold and hot mechanical working of different materials, mainly metals and their alloys.

SUBSTANCE: tool made of high-speed steel P18 may be in the form of cutter, milling cutter, drill, screw tap and so on. High-speed steel of tool contains α-phase - martensite α-Fe alloyed with chrome and tungsten; γ-phase - austenite alloyed with chrome and tungsten; and carbide Fe3W3C. Austenite concentration is no more than 4.4 ± 0.5 mass%; martensite concentration is no less than 84.3 ± 4.0 mass %; concentration of Fe3W3C is equal to 11.3 ± 0.6 mass%.

EFFECT: improved strength, reduced embrittlement, increased useful life period of tool.

1 tbl, 1 ex

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