Method of production of rolled ball-bearing steel

 

The invention relates to ferrous metallurgy, in particular to the modes of deformation and heat treatment zaevtektoidnyh steels, and can be used in the production of round profiles for the manufacture of rolling element bearing. The technical result of the invention is to improve the quality of rolled section by excluding carbide segregation and poloschatosti, reduction in grade carbide residues grid in the annealed condition. The ingot of steel SHKH15 heated to 1240oWith and rolled on the blooming and continuous billet mill in the billet of square section and is cooled at an average speed of 6.5oC/h to 200oWith thermostat, then heated to 1190oWith and rolled on the bar mill in the profile of circular cross section with a total hood 56,6 15 passes, while the temperature of the end of the rolling mill at the outlet of the last stand of the mill support equal to 950oC and cooled water to 825oWith, take up in the booth and cooled in air. table 1.

The invention relates to ferrous metallurgy, in particular to the modes of deformation and heat treatment zaevtektoidnyh steels, and can be used in the production of round profiles for the second heating billets, rolling with the temperature of the end of the rolling AG3+(30-80oC) cooling the critical speed to a temperature of austenite decomposition and final cooling, whereby to produce accelerated cooling roll to a temperature of AG3+(30-80oC) changing the length of the speed before the last 1-5 passes, and cooling with critical velocity to produce Ar1-(Ar1-50oC) [1].

The disadvantages of this method are that when the rolling bearing steels ready rolled sections are of low quality due to the presence of carbide segregation, poloschatosti and carbide mesh in the annealed condition.

There is also known a method of production of steel from zaevtektoidnyh steels, including ball bearing: SHKH15, hug, HUSH. The method includes heating billets, hot deformation and cooling, and heating is carried out until the temperature Acm-(Acm-100oC), and cooling is carried out in air [2].

The disadvantages of this method are the low quality of the rolled due to the presence of carbide segregation, poloschatosti and carbide mesh.

The closest in technical essence and achieve results for th is, kiuchumi heating and rolling of the ingot in the workpiece, the cooling of hot rolled billets, subsequent heating to a temperature of austenitization 1120-1180oWith multi-pass rolling to final dimensions with temperature end of rolling 930-970oWith accelerated cooling water to a temperature of 800-850oAnd the final cooling [3] is a prototype.

In this way, the production of long-rolled products of ball-bearing steel in the finished profile contains carbide porosity and banding, and after annealing profiles for further processing in the metal structure are manifested remains carbide mesh. This reduces the quality of the rolled section.

The technical problem solved by the present invention is to improve the quality of rolled section by excluding carbide segregation and poloschatosti, reduction in grade carbide residues grid in the annealed condition.

To solve the technical problem in the known method of production of long-rolled products of ball bearing steels, including the cooling of hot rolled billets, subsequent heating to a temperature of austenitization, multi-pass rolling with the temperature of the end of rolling to 930-970oWith accelerated onlnie hot rolled billet is produced to a temperature of 190-210oWith an average speed of 5-8oC/h, and multi-pass rolling is conducted with total extraction 24-89.

The invention consists in the following. Rolling ingot zaevtektoidnoj steel billet is accompanied by the destruction of the cast structure, the shredding of large carbides and crystallites. Subsequent slow cooling of the workpiece to a temperature of 190-210oWith speeds of 5-8oWith/h leads to a uniform recrystallization of the deformed grains, and the selection zaevtektoidnyh carbides occurs inside the grains, which contributes to the reduction of carbide segregation and poloschatosti.

Heating the billet to a temperature of austenitization leads to complete dissolution of carbide mesh. During rolling of the workpiece with a total hood 24-89 and simultaneously cooled to the temperature of the end of the rolling 930-970oSince there is a continuous formation of dislocations, which appear and are fixed inside the grains of the primary carbides. Accelerated cooling of the steel with water to a temperature of 800-850oProvides rapid passage mikrotechna temperature range, the selection of carbides at the grain boundaries does not occur, all remain in the volume of the grains of the microstructure, carbide mesh completely otsuchi poloschatosti. Cooling of rolled in the air captures the optimal microstructure of the steel.

Annealing of hot-rolled required for subsequent processing, accompanied by loss of strength of the metal matrix of the steel, the formation of fine-grained perlite with inclusions of secondary carbides, minor manifestation of open and depleted residues carbide mesh size of 0.5 points, because the vast number of carbides fixed inside the grains of the microstructure.

It was established experimentally that during slow cooling of hot rolled billet with an average speed above 8oC/h to a temperature above 210oWith saved carbide porosity and banding, ready rolled after annealing carbide mesh reaches 1-2 points. The decrease in the average cooling rate is less than 5oC/h and end temperature of cooling below 190oWith no leads to further enhance the quality of rolled, but only lengthens the production cycle, resulting in inappropriate.

In multi-pass rolling with a total extract of less than 24 is not achieved complete elimination of carbide segregation and do not provide education of a sufficient number disloca the persons grains. The increase in total extraction over 89 causes the heterogeneity of the microstructure and phase composition of steel due to work hardening of the austenite, which degrades the uniformity of the properties of the finished products.

When the temperature of the end of the rolling above 970oWith no is a complete recrystallization of deformed austenite prior to the beginning of accelerated cooling, the uniformity of the properties of the finished rolled products and its quality deteriorates. The lower temperature end of the rolling below 930oWith not preclude the formation of carbide grid before the beginning of accelerated cooling water, which degrades the quality of the rolled.

When the temperature of the end of the accelerated cooling water above 850oWith not exclude the formation of carbide mesh, which is unacceptable. Reduction of the temperature below 800oWith does not improve the quality of rolled, but only complicates the process, leads to Preobrazhenie steel, reducing the quality of the rolled section.

An example implementation of the method is Extended upward ingot weight of 8.7 tons of ball-bearing steel SHKH15 heated to a temperature of 1240oWith and rolled on the blooming and continuous billet mill in the blank square section 100x100 mm Th is medlenno cooling at an average speed of V03=6,5oC/h to a temperature T03=200oC.

The cooled billet is loaded into the heating furnace and heated to a temperature of austenitization Tn=1190oWith, then make her rolling on the bar mill in the profile of circular cross section with a diameter of 15 mm with a total extract= 56,6 15 passes. The temperature of the end of a rolling (on the output from the last stand) support equal to TCP=950oC.

Emerging from the last stand of the mill varietal profile cool water to a temperature Top=825oAnd then take up in revolt. Further cooling of the rebellion produce on the air.

Due to the aforementioned modes of production, rolled after annealing the consumer at a temperature of 800o(For subsequent drawing and machining) has no carbide segregation and poloschatosti, remains carbide mesh in the microstructure are estimated at 0.5 points. This proves the high quality of the rolled section.

Embodiments of the method of production of long-rolled products of ball-bearing steel and indicators of efficiency are presented in the table.

The table shows that when iodinium steels due to the exclusion of carbide segregation and poloschatosti and reduce points of residues carbide mesh in the annealed condition. In cases of transcendent values of the declared options (options 1 and 5) and the implementation of the prototype method (option 6) in the structure of steel carbide is present, the porosity and banding, point carbide mesh in the annealed rent increases, the quality of the car is obtained below.

Technical appraisal and economic benefits of the proposed method consist in the fact that the developed deformation-thermal modes of production to ensure the destruction of carbide segregation and poloschatosti during multi-pass rolling, the homogenization of the phase composition of steel, the retention of nascent carbides inside the body of the grain microstructure of austenite and fine perlite, depletion of grain boundary carbides, carbide depletion of the grid and reduce it in the annealed condition to a value of 0.5 points. This is achieved by improving the quality of long-rolled products of ball bearing steels.

As the base object when determining the economic efficiency of the adopted method prototype. The use of the proposed method will improve the profitability of production of long-rolled products of ball bearing steels at 8-10%.

Literature 1. Auth. mon. The USSR 1006509, IPC 21 D 8/06, 1985

2. Auth. mon. The USSR 831-235 - the prototype.

Claims

Method for the production of long-rolled products of ball bearing steels, including the cooling of hot rolled billets, subsequent heating to a temperature of austenitization, multi-pass rolling with the temperature of the end of the rolling 930-970oWith accelerated cooling water to a temperature of 800-850oC and subsequent cooling, wherein the cooling of hot-rolled billets are produced to a temperature of 190-210oWith an average speed of 5-8oC/h, and multi-pass rolling is conducted with total extraction 24-89.

 

Same patents:

The invention relates to ferrous metallurgy, in particular to a heat treatment of high carbon steel, and can be used in the manufacture of the cable rod and botofogo strips in the thread wire mills

The invention relates to metal finish the wire and to a method of manufacturing the wire

The invention relates to ferrous metallurgy, in particular to the manufacture of heat-treated rod reinforcing steel in large profiles using the heat rolling heating during thermal hardening steel in the flow medium section mills

The invention relates to metallurgy, and in particular to thermal processing for hire, and can be used for thermal hardening of the reinforcing carbon steel bars

The invention relates to ferrous metallurgy, in particular to the manufacture of heat-treated rod reinforcing steel in small sections with the use of heat rolling heat, and can be used for thermal hardening of rent in the flow of merchant bar mills

The invention relates to metal forming, and more specifically to the drawing production, and can be used in the technological process of manufacturing of cold drawn copper products produced from continuously cast billets NLS)

The invention relates to metallurgy, in particular to the technology of wire from nodular cast iron, which combines high strength and plastic properties with resistance against corrosion

The invention relates to equipment for the heat treatment of metals and can be used in processes requiring fast heating and slow cooling at a given speed, in particular for spheroidizing and recrystallization annealing calibrated steel in coils

The invention relates to equipment for thermal processing of metals and alloys and can be preferably used for annealing, normalizing calibrated steel from mikrotechna temperature range (MCI) and thermolysine (quenching and tempering) calibrated steel, intended for the manufacture of high-strength fasteners by the method of cold forming processes (GHOSH)

The invention relates to equipment for thermal processing of metals and alloys and can be used mainly for recrystallization and spheroidizing annealing and quenching calibrated steel from mikrotechna temperature range (MCI), used in the manufacture of high-strength fasteners by the method of cold forming processes (GHOSH) without final heat treatment

FIELD: rolled tube production, namely method for making pilger mill mandrels from heat resistant steel for rolling hot rolled tubes.

SUBSTANCE: method for making mandrels used for rolling hot rolled tubes with large and mean diameters in range 273-550mm comprises steps of casting ingots of hear resistant steel; forging cylindrical solid or hollow blanks, roughly working of them, performing heat treatment and finishing mandrels at forming conicity 1 - 2 mm on length of their working portion while taking into account designed linear expansion coefficient during rolling process; determining diameter size by means of expression δ = dn - Δ/1 + αĚt. One portion of mandrel from lock along length of half of working portion of mandrel is in the form of cone with diameters of cone bases determined form given expression and second portion is in the form of cylinder or truncated cone whose diameters are determined according to next expression

EFFECT: lowered lengthwise thickness difference of tubes.

3 cl, 1 dwg, 1 tbl

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: 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 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 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: ferrous metallurgy.

SUBSTANCE: invention provides round-profiled iron smelted from medium-carbon high-plasticity steel composed of, wt %: carbon 0.27-0.32, manganese 0.30-0.50, silicon 0.01-0.37, chromium 0.01-0.25, sulfur 0.005-0.020, niobium 0.005-0.02, calcium 0.001-0.010, iron and unavoidable impurities - the balance. When following relationships are fulfilled: 12/C-Mn/0.03 ≥ 20, 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 10-30 mm; carbon-free layer not exceeding 1.5% diameter; cold setting value at least 1/3 height; point of maximum load not higher than 620 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 ensured improved characteristics of in-process plasticity and low level of stray hardening.

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.

1 ex

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

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

Up!