CN115430812B - Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft - Google Patents
Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft Download PDFInfo
- Publication number
- CN115430812B CN115430812B CN202210973177.4A CN202210973177A CN115430812B CN 115430812 B CN115430812 B CN 115430812B CN 202210973177 A CN202210973177 A CN 202210973177A CN 115430812 B CN115430812 B CN 115430812B
- Authority
- CN
- China
- Prior art keywords
- rolling
- continuous casting
- percent
- reduction
- cooling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 38
- 229910000677 High-carbon steel Inorganic materials 0.000 title claims abstract description 16
- 230000005540 biological transmission Effects 0.000 title claims abstract description 14
- 238000009749 continuous casting Methods 0.000 claims abstract description 36
- 238000001816 cooling Methods 0.000 claims abstract description 34
- 238000005096 rolling process Methods 0.000 claims abstract description 33
- 238000005204 segregation Methods 0.000 claims abstract description 32
- 238000003756 stirring Methods 0.000 claims abstract description 31
- 230000008569 process Effects 0.000 claims abstract description 29
- 230000009467 reduction Effects 0.000 claims abstract description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 21
- 239000010959 steel Substances 0.000 claims abstract description 21
- 238000005266 casting Methods 0.000 claims description 12
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 229910001562 pearlite Inorganic materials 0.000 claims description 10
- 229910000859 α-Fe Inorganic materials 0.000 claims description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 238000004886 process control Methods 0.000 claims description 4
- 238000007711 solidification Methods 0.000 claims description 4
- 230000008023 solidification Effects 0.000 claims description 4
- 239000000443 aerosol Substances 0.000 claims description 3
- 238000009826 distribution Methods 0.000 claims description 3
- 239000007790 solid phase Substances 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims 1
- 239000013078 crystal Substances 0.000 abstract description 22
- 210000001787 dendrite Anatomy 0.000 abstract description 8
- 238000005272 metallurgy Methods 0.000 abstract description 2
- 238000004513 sizing Methods 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 8
- 238000011946 reduction process Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 229910000954 Medium-carbon steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
- B21B1/463—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/114—Treating the molten metal by using agitating or vibrating means
- B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/122—Accessories for subsequent treating or working cast stock in situ using magnetic fields
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/18—Controlling or regulating processes or operations for pouring
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/22—Controlling or regulating processes or operations for cooling cast stock or mould
- B22D11/225—Controlling or regulating processes or operations for cooling cast stock or mould for secondary cooling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/002—Heat treatment of ferrous alloys containing Cr
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Continuous Casting (AREA)
Abstract
The invention belongs to the technical field of metallurgy, and particularly relates to a control method for uniform structure of medium-high carbon steel for an automobile constant-speed transmission shaft, which combines continuous casting dynamic soft reduction and terminal large electromagnetic stirring with double control to reduce center segregation, wherein the total reduction is controlled to be 10-12 mm, and the stirring current is 300A; the large electromagnetic stirring and the secondary cooling weak-cooling control of the crystallizer are adopted, the equiaxed crystal area is enlarged, and the dendrite segregation is lightened, wherein the crystallizer is used for electrically stirring the current 350A. The rolling on-line normalizing rolling control and cooling control process is adopted to ensure that the structure is uniform and can replace normalizing, wherein the rolling control and cooling control temperature is controlled by adopting a water tank, and a KOCKS three-roller reducing sizing mill is used for final rolling. The method improves the component segregation of medium-high carbon steel, ensures that the steel structure has higher uniformity and can replace normalizing, and obtains the transmission shaft parts with high quality and high fatigue life.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to a control method for uniform structure of medium-high carbon steel for an automobile constant-speed transmission shaft.
Background
The transmission shaft is an important part for transmitting power in an automobile transmission system and is a key part for ensuring safe running of a vehicle. The outer star wheel of the constant-speed transmission shaft is generally manufactured by using medium-high carbon steel, the medium-high carbon steel has excellent processing and mechanical properties, but the steel is heavier and heavier along with the increase of the carbon content, so that the uneven structures such as bands, black cores (center segregation), mixed crystals and the like are more easily generated, the heat treatment deformation of parts and the like are caused, and the service fatigue life of the transmission shaft is seriously influenced.
Medium-high carbon steel is treated by liquid-solid line temperature (T) l ～T s ) The interval is larger, in the solidification process of the casting blank, the interaction of the easily segregated elements such as C, mn, S, P is easy to form serious center segregation, the feeding of molten steel along a liquid phase cavity, particularly the solidification tail end is blocked, the center of the casting blank is loose, and shrinkage cavity is seriously formed. The severity of central porosity, shrinkage cavity and segregation of a casting blank depends on the proportion of columnar crystals and equiaxed crystals, and the higher the liquid-solid line temperature gradient is, the more developed the columnar crystals grow, and the heavier the central segregation and porosity are. Thus, how to alleviate center segregation and center porosity of medium and high carbon steelIs always a difficult problem in the industry.
The structural uniformity of steel has several main effects: firstly, dendrite segregation (micro segregation) of a cast slab may cause structural non-uniformity of ferrite-pearlite bands (band-like structures); secondly, the central segregation (macrosegregation) of the casting blank can cause the structural non-uniformity of the steel black core (central mixed crystal); again, the rolling temperature and process control are not suitable, resulting in uneven structure such as coarse grains and mixed crystals at the edges. At present, in order to achieve uniform organization, users need to normalize steel before using the steel.
The invention aims to improve the component segregation (micro segregation and macro segregation) of medium-high carbon steel, realize the uniform structure of ferrite and pearlite to replace normalizing, improve the service performance of materials and obtain the transmission shaft with high quality and high fatigue life.
Disclosure of Invention
The purpose of the invention is that: the control method for the uniform structure of the medium-high carbon steel for the constant-speed transmission shaft of the automobile is provided, and the continuous casting and rolling process capable of improving the composition segregation and replacing the structure of uniform ferrite and pearlite is provided.
The invention aims at realizing the purposes by the following technical scheme:
(1) The continuous casting adopts a large-section low-pulling-speed process, the section of a casting blank is 300mm multiplied by 325mm, the pulling speed is 0.75-0.80 m/min, the low superheat degree is controlled at 15-30 ℃, the temperature gradient is reduced, the developed growth of columnar crystals is prevented, the segregation of dendrites is reduced, and the generation of the structural non-uniformity of ferrite and pearlite strips is prevented.
(2) The continuous casting light rolling process adopts large rolling reduction and continuous small rolling reduction of multiple rollers (5 rolling reduction rollers), the total rolling reduction is 10-12 mm, when the central solid phase rate is 0.50-1, the rolling reduction is 8-10 mm, no. 1-4 rollers are used, and the single rolling reduction is less than 3.0mm; when the simulated core temperature of the cast slab is lower than the solidification (solid phase) temperature, the reduction is 2mm, and a No. 5 roll is used.
(3) The continuous casting tail end electromagnetic stirring process is matched with the soft reduction process for use, the electric stirring current is 300 A+/-10A, the frequency is 6.0+/-0.2 HZ, and the central porosity and central segregation are better improved through the combined use with the soft reduction process, so that the tissue non-uniformity caused by the component segregation (especially carbon element) is reduced.
(4) The electromagnetic stirring process of the continuous casting crystallizer adopts high-current stirring, the current is 350 A+/-10A, the frequency is 2.0+/-0.2 HZ, columnar crystals are broken, nucleation points are increased, an equiaxed crystal area is enlarged, and dendrite segregation is reduced.
(5) The secondary cooling process of continuous casting adopts a weak cooling mode, and is matched with large electromagnetic stirring of a crystallizer, the specific water quantity is controlled to be 0.12L/kg-0.15L/kg, the temperature difference between the inside and the outside of a casting blank is reduced, the developed growth of columnar crystals is prevented, and the equiaxed crystal area is enlarged. Wherein, each section is cooled: the foot roller section adopts full water cooling, the first area, the second area and the third area adopt aerosol cooling, and the water distribution ratio is 45 percent: 22%:20%:13%.
(6) The on-line normalizing rolling and cooling control process controls the temperature before entering the KOCKS unit to be 800-850 ℃, and the steel throwing temperature (upper cooling bed temperature) to be 780-830 ℃, wherein the water tank before entering the KOCKS unit uses a No. 1-4 water tank, a No. 5 water tank is not used, enough time is given to evenly enter the temperature before the KOCKS, and a No. 6 water tank is used after rolling.
The beneficial effects of the invention are as follows: dynamic soft reduction of continuous casting and large electromagnetic stirring at the tail end are combined with double control, so that center segregation is reduced; the large electromagnetic stirring and the secondary cooling weak cooling control of the crystallizer are adopted, the equiaxed crystal area is enlarged, and the dendrite segregation is reduced. The normalizing is replaced by a uniform structure through an online normalizing rolling and cooling control process. So as to achieve the purposes of improving the component segregation (micro segregation and macro segregation) of the medium-high carbon steel, realizing the uniform structure of ferrite and pearlite to replace normalizing, improving the comprehensive use performance of the material and obtaining the transmission shaft with high quality and high fatigue life.
Description of the drawings:
FIG. 1 is a photograph showing the low-magnification test of the steel obtained in example 1.
FIG. 2 is a photograph showing the transverse structure of the steel obtained in example 1.
FIG. 3 is a photograph showing the low-magnification test of the steel obtained in comparative example 1.
FIG. 4 is a photograph showing the transverse structure of the steel obtained in comparative example 1.
FIG. 5 is a photograph showing the transverse structure of the steel obtained in comparative example 3.
FIG. 6 is a photograph showing the mixed crystal examination of the steel obtained in comparative example 3.
Detailed Description
The invention is further illustrated below in connection with specific examples, but the scope of the invention is not limited to the following examples.
Taking medium and high carbon steel 55 steel as an example, the chemical components are as follows: 0.55% of C, 0.26% of Si, 0.78% of Mn, 0.27% of Cr, 0.010% of P, 0.016% of S, 0.025% of Al, and the balance of Fe and impurity elements. A5-machine 5-strand arc continuous casting machine with a section of 300mm by 325mm was used.
Example 1
(1) The continuous casting adopts a large-section low-pulling-speed process, the pulling speed of the casting blank is 300mm multiplied by 325mm, the pulling speed is 0.75/min, the low superheat degree is controlled at 28 ℃, the temperature gradient is reduced, the developed growth of columnar crystals is prevented, the segregation of dendrites is reduced, and the generation of the structural non-uniformity of ferrite and pearlite strips is prevented.
(2) The continuous casting light reduction process adopts a large reduction and a plurality of rollers (5 reduction rollers) for continuously reducing the small reduction;
the continuous casting soft reduction process is shown in the following table:
| press roller | No. 1 | No. 2 | No. 3 | No. 4 | No. 5 | Total depression mm |
| Reduction of depression | 1.5 | 2.2 | 2.3 | 2 | 2 | 10 |
(3) The continuous casting tail end electromagnetic stirring process is matched with the soft reduction process for use, and the electric stirring current 310A and the frequency of 6.0HZ are combined with the soft reduction for use, so that the center porosity and center segregation are better improved, and the tissue non-uniformity caused by component segregation (especially carbon element) is reduced.
(4) The electromagnetic stirring process of the continuous casting crystallizer adopts high-current stirring, the current is 350A, the frequency is 2.0HZ, columnar crystals are broken, nucleation points are increased, an equiaxed crystal area is enlarged, and dendrite segregation is reduced.
(5) The secondary cooling process of continuous casting adopts a weak cooling mode, and is matched with large electromagnetic stirring of a crystallizer, the specific water quantity is controlled at 0.14L/kg, the temperature difference between the inside and the outside of a casting blank is reduced, the developed growth of columnar crystals is prevented, and the equiaxed crystal area is enlarged. Wherein, each section is cooled: the foot roller section adopts full water cooling, the first area, the second area and the third area adopt aerosol cooling, and the water distribution ratio is 45 percent: 22%:20%:13%.
(6) The on-line normalizing rolling and cooling control process controls the temperature before entering the KOCKS unit to be 800 ℃, and the steel throwing temperature (upper cooling bed temperature) to be 780 ℃, wherein a No. 1-4 water tank is used for the water tank before entering the KOCKS unit, a No. 5 water tank is not used, enough time is given for evenly entering the temperature before the KOCKS, and a No. 6 water tank is used after rolling.
Example 2
(1) The continuous casting drawing speed is 0.78m/min, and the superheat degree is 25 ℃.
(2) The end electromagnetic stirring current 300A, frequency 6HZ, continuous casting soft reduction process is shown in the following table:
| press roller | No. 1 | No. 2 | No. 3 | No. 4 | No. 5 | Total depression mm |
| Reduction of depression | 2.1 | 2.5 | 2.5 | 2.1 | 2 | 11.2 |
(3) The temperature of the rolling on-line normalizing process before KOCKS is 820 ℃ and the steel throwing temperature is 806 ℃.
(4) The other processes were the same as in example 1.
Example 3
(1) The continuous casting drawing speed is 0.80m/min, and the superheat degree is 26 ℃.
(2) The end electromagnetic stirring current 295A, frequency 6HZ, continuous casting soft reduction process is shown in the following table:
| press roller | No. 1 | No. 2 | No. 3 | No. 4 | No. 5 | Total depression mm |
| Reduction of depression | 2.3 | 2.6 | 2.6 | 2.5 | 2 | 12 |
(3) The temperature of the rolling on-line normalizing process before KOCKS is 850 ℃ and the steel throwing temperature is 812 ℃.
(4) The other processes were the same as in example 1.
Comparative example 1
(1) The continuous casting adopts a large-section low-pulling-speed process, the pulling speed of the casting blank is 300mm multiplied by 325mm, the pulling speed is 0.75/min, the low superheat degree is controlled at 28 ℃, the temperature gradient is reduced, the developed growth of columnar crystals is prevented, the segregation of dendrites is reduced, and the generation of the structural non-uniformity of ferrite and pearlite strips is prevented.
(2) An electromagnetic stirring process for continuous casting tail end, which comprises the steps of electric stirring current 100A and frequency 6HZ.
The electromagnetic stirring process, the secondary cooling process and the rolling on-line normalizing rolling control cooling process of the continuous casting crystallizer are the same as those of the embodiment 1.
Comparative example 2
(1) The continuous casting adopts a large-section low-pulling-speed process, a continuous casting soft-reduction process and a continuous casting tail end electromagnetic stirring process which are the same as those of the embodiment 1.
The electromagnetic stirring process current of the continuous casting tail end is 250A, and the frequency is 2.0HZ; the secondary cooling process of continuous casting adopts a medium-strong cooling mode, and the specific water quantity is 0.20L/kg.
The rolling on-line normalizing rolling and cooling control process is the same as in example 1.
Comparative example 3
Step (1) to step (5) are the same as in example 1.
In the step (6), the rolling on-line normalizing process is not adopted, the temperature before KOCKS is 880 ℃, the steel throwing temperature is 872 ℃, and the water tank is not adopted to control the temperature.
In examples 1 to 3 of the present invention, comparative examples 1 to 3 were compared with the following table in terms of center carbon segregation (difference between center carbon content of steel and carbon content of melting component/melting component), ferrite and pearlite structure uniformity rating (GB/T13320), mixed crystal phenomenon, and grain size level:
the results show that: the center segregation is improved by combining continuous casting dynamic soft reduction and end large electromagnetic stirring with double control, the equiaxial crystal area is enlarged by large electromagnetic stirring and two-cooling weak-cooling control of a crystallizer, and an online normalizing rolling control cooling process is adopted, so that uniform structures of ferrite and pearlite are obtained, and the normalizing can be completely replaced.
The above embodiments are all preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and all modifications of the above embodiments according to the technical principles of the present invention are included in the scope of the present invention.
Claims (2)
1. The control method of the uniform structure of the medium-high carbon steel for the constant-speed transmission shaft of the automobile is characterized by comprising the following steps of: the method comprises the following steps of continuous casting light reduction, continuous casting electromagnetic stirring, continuous casting secondary cooling and rolling on-line normalizing:
(1) Continuous casting adopts a large-section low-drawing speed and low-superheat process, and the section of a casting blank is 300mm multiplied by 325mm;
(2) The continuous casting light reduction adopts a large reduction and a multi-roller continuous small reduction, and the total reduction of the light reduction is 10-12 mm;
when the solid phase rate of the center of the casting blank is more than or equal to 0.50 and less than or equal to 1, the rolling reduction is 8-10 mm, a No. 1-4 roller is used, and the single-roller rolling reduction is less than or equal to 3.0mm; when the core temperature of the casting blank is lower than the solidification temperature, the rolling reduction is 2mm, and a No. 5 roller is used;
(3) Electromagnetic stirring at the tail end of continuous casting, and electric stirring current 300 A+/-10A and frequency 6.0+/-0.2 HZ by matching with a soft pressing process;
(4) Electromagnetic stirring of the continuous casting crystallizer adopts high-current stirring, wherein the current is 350 A+/-10A, and the frequency is 2.0+/-0.2 HZ;
(5) Continuous casting secondary cooling adopts a weak cooling mode, and is matched with large electromagnetic stirring of a crystallizer, and the specific water quantity is controlled to be 0.12L/kg-0.15L/kg;
and (3) cooling each section of the step (5): the foot roller section adopts full water cooling, the first area, the second area and the third area adopt aerosol cooling, and the water distribution ratio is 45 percent: 22%:20%:13%;
(6) The rolling online normalizing rolling control cooling process controls the temperature before entering the KOCKS unit to be 800-850 ℃ and the steel throwing temperature to be 780-830 ℃, wherein a No. 1-4 water tank is used for the water tank before entering the KOCKS unit, a No. 5 water tank is not used, and a No. 6 water tank is used after rolling;
the chemical components of the medium-high carbon steel are as follows by weight percent: 0.50 to 0.56 percent of C, 0.15 to 0.30 percent of Si, 0.65 to 0.80 percent of Mn, 0.020 to 0.030 percent of Cr, less than or equal to 0.020 percent of P, 0.010 to 0.025 percent of S, 0.015 to 0.040 percent of Al, and the balance of Fe and impurity elements; the central carbon segregation of the medium-high carbon steel is less than or equal to 8 percent, the ferrite and pearlite structure is uniform, and the grain size is more than or equal to 7 grades.
2. The method for controlling the uniform structure of medium-high carbon steel for a constant speed transmission shaft of an automobile according to claim 1, wherein the pulling speed of the step (1) is 0.75-0.80 m/min, and the superheat degree is controlled at 15-30 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210973177.4A CN115430812B (en) | 2022-08-15 | 2022-08-15 | Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210973177.4A CN115430812B (en) | 2022-08-15 | 2022-08-15 | Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115430812A CN115430812A (en) | 2022-12-06 |
| CN115430812B true CN115430812B (en) | 2024-01-23 |
Family
ID=84242993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210973177.4A Active CN115430812B (en) | 2022-08-15 | 2022-08-15 | Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115430812B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02151354A (en) * | 1988-12-02 | 1990-06-11 | Nippon Steel Corp | Method for improving segregation in continuously cast slab |
| KR20010048739A (en) * | 1999-11-29 | 2001-06-15 | 이구택 | Method for continuous casting bearing steel |
| JP2009183977A (en) * | 2008-02-06 | 2009-08-20 | Kobe Steel Ltd | Light rolling reduction method for slab in continuous casting |
| CN103121092A (en) * | 2013-03-22 | 2013-05-29 | 北京科技大学 | Continuous casting bloom soft press technology based on tail end electromagnetic stirring |
| CN106475542A (en) * | 2016-11-16 | 2017-03-08 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of axle steel and its continuous cast method |
| CN110303131A (en) * | 2019-07-22 | 2019-10-08 | 攀钢集团攀枝花钢铁研究院有限公司 | Large section Properties of Heavy Rail Steel disperse is segregated control method |
| CN113000803A (en) * | 2021-02-24 | 2021-06-22 | 建龙北满特殊钢有限责任公司 | Continuous casting process method for improving internal quality of high-carbon steel bloom |
| CN113957321A (en) * | 2021-10-14 | 2022-01-21 | 中天钢铁集团有限公司 | Non-quenched and tempered steel for transmission shaft and preparation method of forging of non-quenched and tempered steel |
| CN113957340A (en) * | 2021-10-14 | 2022-01-21 | 中天钢铁集团有限公司 | Control method for medium-carbon high-manganese vanadium-containing alloy structure round steel material structure |
-
2022
- 2022-08-15 CN CN202210973177.4A patent/CN115430812B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02151354A (en) * | 1988-12-02 | 1990-06-11 | Nippon Steel Corp | Method for improving segregation in continuously cast slab |
| KR20010048739A (en) * | 1999-11-29 | 2001-06-15 | 이구택 | Method for continuous casting bearing steel |
| JP2009183977A (en) * | 2008-02-06 | 2009-08-20 | Kobe Steel Ltd | Light rolling reduction method for slab in continuous casting |
| CN103121092A (en) * | 2013-03-22 | 2013-05-29 | 北京科技大学 | Continuous casting bloom soft press technology based on tail end electromagnetic stirring |
| CN106475542A (en) * | 2016-11-16 | 2017-03-08 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of axle steel and its continuous cast method |
| CN110303131A (en) * | 2019-07-22 | 2019-10-08 | 攀钢集团攀枝花钢铁研究院有限公司 | Large section Properties of Heavy Rail Steel disperse is segregated control method |
| CN113000803A (en) * | 2021-02-24 | 2021-06-22 | 建龙北满特殊钢有限责任公司 | Continuous casting process method for improving internal quality of high-carbon steel bloom |
| CN113957321A (en) * | 2021-10-14 | 2022-01-21 | 中天钢铁集团有限公司 | Non-quenched and tempered steel for transmission shaft and preparation method of forging of non-quenched and tempered steel |
| CN113957340A (en) * | 2021-10-14 | 2022-01-21 | 中天钢铁集团有限公司 | Control method for medium-carbon high-manganese vanadium-containing alloy structure round steel material structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115430812A (en) | 2022-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110777300B (en) | Method for manufacturing high-carbon chromium bearing steel | |
| CN114393185B (en) | Method for improving equiaxial crystal rate of non-oriented electrical steel casting blank at high continuous casting speed | |
| CN111254256B (en) | Bearing steel and manufacturing method thereof | |
| WO2023060877A1 (en) | Control method for medium-carbon high-manganese vanadium-containing alloy structural round steel material structure | |
| CN115283634B (en) | Method for controlling equiaxial crystal rate of medium-high grade silicon steel | |
| CN111230061B (en) | Method for reducing carbon segregation of medium carbon steel round billet | |
| CN110396648A (en) | A kind of special thick alloy mold steel plate of continuous casting billet production and its manufacturing method | |
| CN113134585A (en) | Homogenization square billet continuous casting production method under action of outfield cooperative control | |
| CN113084110B (en) | Method for reducing carbon segregation of alloy steel | |
| CN115430812B (en) | Control method for uniform structure of medium-high carbon steel for automobile constant-speed transmission shaft | |
| CN116140578A (en) | Continuous casting method for improving center segregation of high-carbon steel billets | |
| CN110983204B (en) | Steel plate for engineering machinery and preparation method | |
| CN114905010A (en) | Nickel-based alloy wire and preparation method thereof | |
| CN117226059B (en) | Reduction control method for improving macro-segregation and semi-macro-segregation of high-carbon low-alloy steel | |
| CN112355264A (en) | Method for controlling center porosity of heavy rail steel bloom | |
| CN114653907B (en) | Method for improving homogeneity of high-carbon steel billet casting blank based on brand new depressing mode | |
| CN114226671B (en) | Bearing steel and production method thereof, and bearing ring and production method thereof | |
| CN114054706B (en) | Production control method for improving pickling low-power quality of bearing steel round steel | |
| CN115537640B (en) | ZW931 roller of lithium ion battery pole piece rolling mill and preparation method thereof | |
| CN114774624B (en) | Special steel and preparation method thereof | |
| CN117737613A (en) | Preparation method of continuous casting large round billet for forging cold roll sleeve | |
| CN116623067B (en) | Production process of oriented silicon steel thin strip | |
| CN117004882A (en) | Steel for cross wedge rolling gear shaft and preparation method thereof | |
| CN116117088A (en) | Method for producing non-oriented silicon steel by adopting electromagnetic stirring in sheet billet continuous casting | |
| CN115401175A (en) | Method for producing large-size high-carbon chromium bearing steel bar with small compression ratio |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |