CN116497198A - 55SiCrV spring steel bloom one-fire forming method for high-stress automobile stabilizer bar - Google Patents
55SiCrV spring steel bloom one-fire forming method for high-stress automobile stabilizer bar Download PDFInfo
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- CN116497198A CN116497198A CN202310238265.4A CN202310238265A CN116497198A CN 116497198 A CN116497198 A CN 116497198A CN 202310238265 A CN202310238265 A CN 202310238265A CN 116497198 A CN116497198 A CN 116497198A
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- 229910000639 Spring steel Inorganic materials 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000003381 stabilizer Substances 0.000 title claims abstract description 21
- 238000010438 heat treatment Methods 0.000 claims abstract description 48
- 238000005096 rolling process Methods 0.000 claims abstract description 29
- 238000001816 cooling Methods 0.000 claims abstract description 14
- 238000009749 continuous casting Methods 0.000 claims abstract description 8
- 238000007689 inspection Methods 0.000 claims abstract description 8
- 238000003723 Smelting Methods 0.000 claims abstract description 7
- 238000007670 refining Methods 0.000 claims abstract description 7
- 238000004806 packaging method and process Methods 0.000 claims abstract description 5
- 238000009489 vacuum treatment Methods 0.000 claims abstract description 5
- 239000007789 gas Substances 0.000 claims description 19
- 238000002791 soaking Methods 0.000 claims description 16
- 238000002485 combustion reaction Methods 0.000 claims description 8
- 239000000446 fuel Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- 230000006835 compression Effects 0.000 claims description 7
- 238000007906 compression Methods 0.000 claims description 7
- 229910001566 austenite Inorganic materials 0.000 claims description 4
- 239000013078 crystal Substances 0.000 claims description 4
- 229910001562 pearlite Inorganic materials 0.000 claims description 3
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 239000002737 fuel gas Substances 0.000 claims description 2
- 230000007547 defect Effects 0.000 abstract description 5
- 230000033764 rhythmic process Effects 0.000 abstract description 2
- 238000001514 detection method Methods 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000000571 coke Substances 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000005098 hot rolling Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910006639 Si—Mn Inorganic materials 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 210000001787 dendrite Anatomy 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- 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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
-
- 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
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a 55SiCrV spring steel bloom one-fire forming method for a high-stress automobile stabilizer bar, which is characterized by comprising the following process flows: smelting in an electric furnace/converter, LF refining, VD/RH vacuum treatment, bloom continuous casting, stack cooling, heating in a stepping continuous heating furnace, 10-pass primary rolling and 10-pass middle rolling, primary cooling, 4-pass pre-finish rolling, secondary cooling, 4-pass KOCKS rolling mill finish rolling, final cooling temperature control, inspection and packaging. The invention can realize the comprehensive control of key indexes influencing fatigue performance, such as depth of decarburized layer, compactness and uniformity of internal structure, surface defects and the like of the finished spring steel by proper heating and rolling rhythms and gas control.
Description
Technical Field
The invention relates to a method for forming a 55SiCrV spring steel bloom for a high-stress automobile stabilizer bar by one fire, belonging to the field of alloy steel and manufacturing processes.
Background
The automobile stabilizer bar is one of important parts of an automobile chassis system, and the main materials are Si-Mn series, crMn series and SiCrV series spring steel bars and alloy structural steel pipes which are emerging in recent years. The main specification phi of the spring steel bar for the automobile stabilizer bar is 15-27mm, and the current main production flow comprises two flows of bloom two-fire forming (electric furnace/converter smelting, external refining, vacuum treatment, bloom continuous casting, cogging, blank finishing and grinding, hot rolling forming) and bloom one-fire forming (electric furnace/converter smelting, external refining, vacuum treatment, continuous casting (the blank shape is generally smaller than 240mm square), blank finishing and grinding and hot rolling forming).
Both processes have advantages and disadvantages. The secondary fire forming material has the advantages that the compression ratio is large, the secondary heating is beneficial to ensuring the uniformity and compactness of the material, and the surface quality is good; the disadvantage is high cost, and the secondary heating is unfavorable for the decarburization control of the spring steel. The small square billet one-fire forming has the advantages of short flow, high-efficiency production, lower cost and decarburization control due to lower rolling heating temperature; the disadvantage is that the small compression ratio is not beneficial to control of tissue uniformity and compactness.
Disclosure of Invention
The invention aims to provide a method for producing 55SiCrV spring steel material for high-stress automobile stabilizer bar with a large square billet one-fire forming route, low cost, high efficiency and high quality by controlling a heating process and a rolling process, integrating the advantages of the two-fire forming and the one-fire forming of spring steel and overcoming the defects of the two.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a55 SiCrV spring steel bloom one-shot forming method for a high-stress automobile stabilizer bar is characterized by comprising the following process flows: smelting in an electric furnace/converter, LF refining, VD/RH vacuum treatment, bloom continuous casting, stack cooling, heating in a stepping continuous heating furnace, 10-pass initial rolling and 10-pass middle rolling, primary cooling, 4-pass pre-finish rolling, secondary cooling, 4-pass KOCKS rolling mill finish rolling, final cooling temperature control, inspection and packaging; wherein:
five sections of heating are adopted for heating the stepping type continuous heating furnace, wherein the temperature of a preheating section is less than or equal to 800 ℃, the temperature of a first heating section is less than or equal to 930 ℃, and the temperature of a second heating section is less than or equal to: 950-1080 ℃, soaking a first section of temperature 1030-1140 ℃ and soaking a second section of temperature 1030-1160 ℃; the total heating time is 180 min-240 min;
the fuel gas adopts blast furnace gas or high-coke-to-mixed gas, wherein the air-fuel ratio of a combustion section of the blast furnace gas is controlled to be 0.60-0.85, and the air-fuel ratio of a combustion section of the high-coke-to-mixed gas is controlled to be 2.0-2.6;
adopting a large square billet with the diameter of more than 250mm and a large compression ratio, namely forming a material by one fire, wherein the compression ratio is more than 120.
Preferably, the preheating stage temperature: 650-660 ℃, heating for a period of temperature: 860-890 ℃, and heating two stages of temperatures: soaking at 1010-1035 deg.c for one period of temperature: 1075-1090 ℃, soaking two-stage temperature: 1095-1130 ℃, total heating time: 190-210min.
Another preferred preheating stage temperature: 620-680 ℃, heating for a period of temperature: 860-890 ℃, and heating two stages of temperatures: soaking at 1010-1020 deg.c for one period of temperature: 1070-1085 ℃, soaking two-stage temperature: 1075-1110 ℃, total heating time: 220-245min.
Preferably, the 55SiCrV spring steel produced by the method has a decarburized layer depth of 0.08-0.14mm.
Preferably, the 55SiCrV spring steel produced by the method has a metallographic structure of pearlite and a small amount of ferrite, and has equiaxial crystal characteristics in the transverse direction and the longitudinal direction.
Preferably, the 55SiCrV spring steel produced by the method has an austenite grain size of 8.5 grade.
The invention has the following advantages:
the transmitter is rolled by a large compression ratio, so that the dendrite tissue in the steel is fully crushed, the tissue is fine and uniform, the compactness is good, and the control of the strength and toughness of the material is facilitated.
The urea can realize the comprehensive control of key indexes such as decarburized layer depth, internal tissue compactness and uniformity, surface defects and the like of the finished spring steel, which influence fatigue performance, by combining proper heating and rolling rhythms with gas control.
Drawings
FIG. 1 is a graph showing the depth of decarburized layer of 55SiCrV spring steel for high stress automotive stabilizer bar produced in example 1;
FIG. 2 is a graph showing the depth of decarburized layer of 55SiCrV spring steel for high stress automotive stabilizer bar produced in example 2;
FIG. 3 is a metallurgical structure of 55SiCrV spring steel for high stress automotive stabilizer bar produced in example 1;
FIG. 4 is a metallurgical structure of 55SiCrV spring steel for high stress automotive stabilizer bar produced in example 2;
FIG. 5 is a schematic view of austenite grains of the finished sample of example 1;
FIG. 6 is a low-power organization chart of the finished product sample of example 1.
Detailed Description
Example 1
The embodiment provides a 55SiCrV spring steel bloom one-fire forming method for a high-stress automobile stabilizer bar, which adopts 250mm 300mm spring steel 55SiCrV-YR billets to roll into 55SiCrV spring round steel with the diameter phi 28m, and comprises the following steps:
BOF converter smelting, LF refining furnace, RH treatment, bloom continuous casting, stack cooling, step-by-step continuous heating furnace heating (preheating section temperature: 650-660 ℃, heating section temperature: 860-890 ℃, heating section temperature: 1010-1035 ℃, soaking section temperature: 1075-1090 ℃, soaking section temperature: 1095-1130 ℃, total heating time: 190-210min. Gas is blast furnace gas or high coke transfer mixed gas, wherein the air-fuel ratio of the blast furnace gas combustion section is controlled to be 0.60-0.85, the air-fuel ratio of the high coke transfer mixed gas combustion section is controlled to be 2.0-2.6), 20-pass rolling (10-pass initial rolling+10-pass intermediate rolling), 4-pass finish rolling, 4-pass CKS rolling, inspection, flaw detection (UT+ET), inspection, packaging, metering and warehousing.
The finished product produced by the method has good physical and chemical detection performance and good surface state:
1. low power
2. Depth of decarburized layer
| Test results | 0.08-0.12mm |
3. Grain size (heat treatment temperature and holding time: 860 ℃ C. Holding 60 min)
| Test results | Grade 8.5 |
4. Mechanical properties
5. Nondestructive testing
| Total count | Number of qualified counts | Flaw detection grade | Percent of pass% | |
| Surface magnetic leakage flaw detection | 607 | 589 | GB/T32547N-0.20 grade | 97.03％ |
| Ultrasonic flaw detection | 607 | 607 | GB/T4162-2008 grade A | 100 |
Example 2
The embodiment provides a 55SiCrV spring steel bloom one-fire forming method for a high-stress automobile stabilizer bar, which adopts 250mm 300mm spring steel 55SiCrV-YR continuous casting bloom to roll into 55SiCrV spring round steel with the diameter phi 28mm, and comprises the following steps:
BOF converter smelting, LF refining furnace, RH treatment, bloom continuous casting, stack cooling, step-by-step continuous heating furnace heating (preheating section temperature: 620-680 ℃, heating section temperature: 860-890 ℃, heating section temperature: 1010-1020 ℃, soaking section temperature: 1070-1085 ℃, soaking section temperature: 1075-1110 ℃, total heating time: 220-245min. Gas is blast furnace gas or high-coke-conversion mixed gas, wherein the air-fuel ratio of a blast furnace gas combustion section is controlled to be 0.60-0.85, the air-fuel ratio of a high-coke-conversion mixed gas combustion section is controlled to be 2.0-2.6), 20-pass rolling (10-pass initial rolling+10-pass intermediate rolling), 4-pass pre-finish rolling, 4-pass KOCKS rolling, inspection, flaw detection (UT+ET), inspection, packaging, metering and warehousing.
The finished product produced by the method has good physical and chemical detection performance and good surface state:
1. low power
2. Depth of decarburized layer
| Test results | 0.12mm-0.14mm |
3. Austenite grain size (heat treatment temperature and holding time: 860 ℃ C. Holding 60 min)
| Test results | Grade 8.5 |
4. Mechanical properties
5. Nondestructive inspection
| Total count | Number of qualified counts | Flaw detection grade | Percent of pass% | |
| Surface magnetic leakage flaw detection | 722 | 711 | GB/T32547N-0.20 grade | 98.4 |
| Ultrasonic flaw detection | 722 | 722 | GB/T4162-2008 grade A | 100 |
Spring steel for 55SiCrV stabilizer bar produced by the method of the invention: the depth of the decarburized layer is small (as shown in figures 1 and 2, the depth of the decarburized layer is 0.08-0.12mm and 0.12-0.14mm respectively); the metallographic structure is pearlite and a small amount of ferrite, and the transverse and longitudinal directions are all good equiaxed crystal characteristics (shown in figures 3 and 4); the finished sample is austenitized after being kept at 860 ℃ for 60min, and the crystal grains are fine (as shown in figure 5, the grain size is 8.5 grade); the finished material was less dense and no significant defects were seen (as shown in fig. 6).
The embodiment shows that the method can realize the comprehensive control of key indexes such as the depth of the decarburized layer, the compactness of the internal structure, the uniformity, the surface defects and the like of the spring steel, which influence the fatigue performance.
In addition to the embodiments described above, other embodiments of the invention are possible. All technical schemes formed by equivalent substitution or equivalent transformation fall within the protection scope of the invention.
Claims (6)
1. A55 SiCrV spring steel bloom one-shot forming method for a high-stress automobile stabilizer bar is characterized by comprising the following process flows: smelting in an electric furnace/converter, LF refining, VD/RH vacuum treatment, bloom continuous casting, stack cooling, heating in a stepping continuous heating furnace, 10-pass initial rolling and 10-pass middle rolling, primary cooling, 4-pass pre-finish rolling, secondary cooling, 4-pass KOCKS rolling mill finish rolling, final cooling temperature control, inspection and packaging; wherein:
five sections of heating are adopted for heating the stepping type continuous heating furnace, wherein the temperature of a preheating section is less than or equal to 800 ℃, the temperature of a first heating section is less than or equal to 930 ℃, and the temperature of a second heating section is less than or equal to: 950-1080 ℃, soaking a first section of temperature 1030-1140 ℃ and soaking a second section of temperature 1030-1160 ℃; the total heating time is 180 min-240 min;
the fuel gas adopts blast furnace gas or high-coke-to-mixed gas, wherein the air-fuel ratio of a combustion section of the blast furnace gas is controlled to be 0.60-0.85, and the air-fuel ratio of a combustion section of the high-coke-to-mixed gas is controlled to be 2.0-2.6;
adopting a large square billet with the diameter of more than 250mm and a large compression ratio, namely forming a material by one fire, wherein the compression ratio is more than 120.
2. The 55SiCrV spring steel bloom one-shot forming process for high stress automotive stabilizer bars of claim 1 wherein the preheat section temperature: 650-660 ℃, heating for a period of temperature: 860-890 ℃, and heating two stages of temperatures: soaking at 1010-1035 deg.c for one period of temperature: 1075-1090 ℃, soaking two-stage temperature: 1095-1130 ℃, total heating time: 190-210min.
3. The 55SiCrV spring steel bloom one-shot forming process for high stress automotive stabilizer bars of claim 1 wherein the preheat section temperature: 620-680 ℃, heating for a period of temperature: 860-890 ℃, and heating two stages of temperatures: soaking at 1010-1020 deg.c for one period of temperature: 1070-1085 ℃, soaking two-stage temperature: 1075-1110 ℃, total heating time: 220-245min.
4. The method of forming a 55SiCrV spring steel bloom for high stress automotive stabilizer bars according to claim 1 wherein the 55SiCrV spring steel produced by said method has a decarburized layer depth of 0.08 to 0.14mm.
5. The method for forming a 55SiCrV spring steel bloom for a high stress automobile stabilizer bar according to claim 1, wherein the 55SiCrV spring steel produced by the method has a metallographic structure of pearlite and a small amount of ferrite, and is characterized by equiaxed crystal in the transverse direction and the longitudinal direction.
6. The 55SiCrV spring steel bloom-forming process for high stress automotive stabilizer bars of claim 1 wherein said process produces 55SiCrV spring steel having an austenite grain size of 8.5 grade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310238265.4A CN116497198A (en) | 2023-03-14 | 2023-03-14 | 55SiCrV spring steel bloom one-fire forming method for high-stress automobile stabilizer bar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310238265.4A CN116497198A (en) | 2023-03-14 | 2023-03-14 | 55SiCrV spring steel bloom one-fire forming method for high-stress automobile stabilizer bar |
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| Publication Number | Publication Date |
|---|---|
| CN116497198A true CN116497198A (en) | 2023-07-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310238265.4A Pending CN116497198A (en) | 2023-03-14 | 2023-03-14 | 55SiCrV spring steel bloom one-fire forming method for high-stress automobile stabilizer bar |
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| Country | Link |
|---|---|
| CN (1) | CN116497198A (en) |
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2023
- 2023-03-14 CN CN202310238265.4A patent/CN116497198A/en active Pending
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