CN113088662A - DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process - Google Patents
DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process Download PDFInfo
- Publication number
- CN113088662A CN113088662A CN202110338594.7A CN202110338594A CN113088662A CN 113088662 A CN113088662 A CN 113088662A CN 202110338594 A CN202110338594 A CN 202110338594A CN 113088662 A CN113088662 A CN 113088662A
- Authority
- CN
- China
- Prior art keywords
- carbon potential
- annealing process
- bearing steel
- spheroidizing annealing
- controlled
- 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.)
- Granted
Links
Images
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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
-
- 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
- C21D1/30—Stress-relieving
-
- 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
- C21D1/32—Soft annealing, e.g. spheroidising
-
- 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
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
-
- 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
- C21D11/00—Process control or regulation for heat treatments
-
- 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
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
Abstract
The invention discloses a method for controlling DX gas carbon potential in a bearing steel tube anaerobic spheroidizing annealing process, wherein the production process of the bearing steel tube comprises a capillary spheroidizing annealing process and a finished product tube stress relief annealing process, in the capillary spheroidizing annealing process and the finished product tube stress relief annealing process, the carbon potential in a furnace is measured by a carbon potential meter, the proportion of natural gas and air in a DX gas generator is adjusted, and the carbon potential is controlled in a preset range; wherein the carbon potential is controlled to be 1.00-1.05% in the capillary spheroidizing annealing process, and the carbon potential is controlled to be 1.00-1.05% in the finished product pipe stress relief annealing process. By adopting the carbon potential control method, the technical requirement that the total decarburized layer is less than or equal to 0.15mm can be met, so that the surface decarburization of the carbon atoms on the surface of the bearing steel pipe cannot be caused by oxidation, and the problem of full decarburization of the bearing steel pipe during oxygen-free annealing is solved.
Description
Technical Field
The invention belongs to the technical field of bearing steel pipe manufacturing, and particularly relates to a method for controlling DX gas carbon potential in an anaerobic spheroidizing annealing process of a bearing steel pipe.
Background
With the realization of nitrogen protection anaerobic annealing in steel pipe spheroidization and annealing, the weakness of nitrogen protection begins to be displayed, which mainly shows that the surface of the anaerobic annealing steel pipe has full decarburization phenomenon, so that decarburized layer can not be completely eliminated during bearing turning, and finally the surface hardness of the bearing can not meet the requirement.
The main causes of the full decarburized layer are: although the protection of nitrogen is adopted, oxygen always enters the furnace at the furnace inlet and furnace outlet, and under the condition of long-time heat preservation in the spheroidizing furnace, the oxygen continuously oxidizes carbon atoms on the surface of the steel pipe, but the amount of the oxygen is not enough to form a surface oxidation layer, so that a decarburized layer falls off along with the oxidation layer, and the surface of the steel pipe is completely decarburized, which is shown in a metallographic picture of figure 1.
Due to the existence of the full decarburized layer, the blank bearing has the condition that individual points are not completely turned, and the decarburized layer is thickened due to diffusion of carbon atoms during subsequent quenching and heating of the bearing, so that the surface decarburized layer cannot be completely ground during fine grinding, and the surface hardness of the bearing cannot meet the design requirement.
Disclosure of Invention
The invention aims to provide a method for controlling the carbon potential of DX gas in an anaerobic spheroidizing annealing process of a bearing steel pipe, which can achieve that the total decarburized layer is less than or equal to 0.15mm, so that carbon atoms on the surface of the bearing steel pipe cannot be decarburized due to oxidation, and the problem of full decarburization of the bearing steel pipe during anaerobic annealing is solved.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for controlling DX gas carbon potential in a bearing steel pipe anaerobic spheroidizing annealing process comprises a capillary spheroidizing annealing process and a finished pipe stress-relief annealing process,
in the blank tube spheroidizing annealing process and the finished tube destressing annealing process, the carbon potential in the furnace is measured by a carbon potential meter, the ratio of natural gas to air in a DX gas generator is adjusted, and the carbon potential is controlled in a preset range;
wherein the carbon potential is controlled to be 1.00-1.05% in the capillary spheroidizing annealing process, and the carbon potential is controlled to be 1.00-1.05% in the finished product pipe stress relief annealing process.
As one example, the carbon potential is controlled to be 1.00% in the capillary spheroidizing annealing process, and the carbon potential is controlled to be 1.00% in the finished pipe stress-relief annealing process. The specific process comprises the following steps: in the capillary spheroidizing process, the furnace temperature is 790 ℃, the oxygen probe outputs 1118mv, and the heat preservation time is 11.5 h; the temperature of the furnace in the finished product pipe stress-relief annealing process is 730 ℃, the output voltage of the oxygen probe is 1103mv, and the heat preservation time is 3.5 h.
As another example, the carbon potential is controlled to be 1.05% in the capillary spheroidizing annealing process, and the carbon potential is controlled to be 1.05% in the finished product pipe stress-relief annealing process.
The invention has the beneficial effects that: by adopting the carbon potential control method, the technical requirement that the total decarburized layer is less than or equal to 0.15mm can be met, so that the surface decarburization of the carbon atoms on the surface of the bearing steel pipe cannot be caused by oxidation, and the problem of full decarburization of the bearing steel pipe during oxygen-free annealing is solved.
Drawings
FIG. 1 is a metallographic photograph showing the total decarburization of the surface of a steel pipe;
FIG. 2 is a metallographic photograph of the total decarburized layer of a DX gas-protected oxygen-free spheroidized capillary;
figure 3 is a metallographic photograph of the total decarburized layer of a DX gas blanketed oxygen free annealed article.
Detailed Description
DX gas is a natural gas such as methane or propane, which is mixed with air at normal temperature and insufficiently combusted to be decomposed into a mixed gas containing nitrogen, hydrogen, carbon monoxide and carbon dioxide. The gas can be widely used for related treatment processes of non-oxidation annealing, anti-oxidation protection and the like of metal materials. However, the applicant finds that the full decarburization phenomenon still exists in the oxygen-free spheroidizing annealing process of the bearing steel pipe, so that the decarburized layer can not be completely eliminated during the bearing turning process, and finally the surface hardness of the bearing can not meet the requirement. The applicant has studied this phenomenon to search for the cause of the occurrence of this phenomenon and a solution to the problem, and found that this problem can be solved by reasonably controlling the carbon potential of DX gas. Therefore, the applicant develops and applies the carbon potential control method of the DX protective gas steel pipe anaerobic annealing process.
The working principle of DX gas is as follows: the natural gas is mainly methane, carbon dioxide, carbon monoxide and hydrogen are formed under the condition of incomplete combustion, the carbon potential in the furnace is measured by a carbon potential meter, the ratio of the natural gas to air in a DX gas generator is adjusted, the carbon potential is controlled in a reasonable range, carbon atoms on the surface of the steel pipe cannot be subjected to surface decarburization caused by oxidation, and the problem of full decarburization of the steel pipe during oxygen-free annealing can be solved.
The production and inspection paths of the bearing steel pipe are generally as follows:
(1) heating and perforating the tube blank to obtain a tubular billet;
(2) annealing the capillary tube to obtain an annealing tube, discharging the annealing tube from a furnace, air cooling, and performing hardness inspection and metallographic structure inspection;
(3) cold drawing and cold rolling the annealing pipe to obtain a finished product pipe;
(4) performing stress relief annealing on the finished product pipe, discharging the finished product pipe from the furnace, performing air cooling, and performing hardness inspection and metallographic structure inspection;
(5) and (4) finishing (straightening, head and tail cutting and the like) the finished pipe after annealing, and carrying out flaw detection and size inspection.
And (3) carrying out bearing steel pipe production tests according to the production and inspection paths, wherein the comparison of the adjustment test and the detection result in the actual operation is as follows:
table one: DX gas protection anaerobic spheroidizing annealing oxygen probe output voltage and carbon potential comparison table
| The carbon potential Cp% | Furnace temp. 790 deg.C voltage mv | Holding time h |
| 1.05 | 1121 | 11.5 |
| 1.00 | 1118 | 11.5 |
| 0.95 | 1115 | 11.5 |
Six samples are taken from the un-spheroidized capillary, the original total decarburized layers are all 0.12mm without full decarburizing, two capillary samples are extracted, spheroidizing annealing is carried out under the control of the carbon potential of the table one, the thickness of the detected maximum total decarburized layer is respectively selected from two groups, the thickness is respectively 0.127mm, 0.128mm and 0.134mm, the phenomenon of full decarburizing is not generated, and the requirements that the decarburized layer is less than or equal to 0.15mm in technical protocols of high-end customers (such as SKF manufacturers, NSK manufacturers and the like) are met, and the metallographic photograph shown in the attached; however, the decarburized layer with 0.95 percent of carbon potential is close to the upper limit and has unqualified risk, and the decarburized layer with the carbon potential controlled at 1.00 percent and 1.05 percent meets the requirement. Considering that the higher the carbon potential, the higher the cost of DX gas, 1.00% of the carbon potential was selected for the capillary spheroidizing annealing process.
Table two: DX gas protection oxygen-free stress-relief annealing oxygen probe output voltage and carbon potential comparison table
| The carbon potential Cp% | Furnace temp. 730 deg.C voltage mv | Holding time h |
| 0.95 | 1100 | 3.5 |
| 1.00 | 1103 | 3.5 |
| 1.05 | 1106 | 3.5 |
The original decarbonization of the capillary tube subjected to spheroidizing annealing according to the table I is respectively 127mm, 128mm and 134mm, the capillary tube corresponding to spheroidizing is cold-drawn into a steel tube, stress relief annealing is carried out under the control of carbon potential according to the table II, the total decarbonization layers after annealing are respectively 0.123mm, 0.121mm and 0.108mm, full decarbonization is avoided, the requirements that the decarbonization layer is less than or equal to 0.15mm in technical protocols of high-end customers (such as SKF manufacturers, NSK manufacturers and the like) are met, and the metallographic photograph shown in the attached figure 3 is obtained.
Example 1:
the carbon potential is controlled to be 1.00 percent in the spheroidizing annealing process of the hollow billet, and the carbon potential is controlled to be 1.00 percent in the stress relief annealing process of the finished product pipe.
Example 2:
the carbon potential is controlled to be 1.05% in the spheroidizing annealing process of the hollow billet, and the carbon potential is controlled to be 1.05% in the stress relief annealing process of the finished product pipe.
In consideration of the relationship between cost and quality, example 1 in which 1.00% of carbon potential is selected as the most preferable example for practical production.
In conclusion of the tests, in the actual production, according to the scheme determined in the spheroidizing annealing of the hollow billet and the stress relief annealing of the finished product pipe, the carbon potential is quantitatively controlled to be 1.00 percent, and the small-batch test production is carried out, which all meet the set technical requirements: the total decarburized layer is less than or equal to 0.15 mm.
Table three: DX gas protection anaerobic spheroidizing annealing oxygen probe output voltage and carbon potential comparison table
| The carbon potential Cp% | Furnace temp. 790 deg.C voltage mv | Holding time h |
| 1.00 | 1118 | 11.5 |
Table four: DX gas protection oxygen-free stress-relief annealing oxygen probe output voltage and carbon potential comparison table
| The carbon potential Cp% | Furnace temp. 730 deg.C voltage mv | Holding time h |
| 1.00 | 1103 | 3.5 |
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.
Claims (5)
1. A DX gas carbon potential control method in the anaerobic spheroidizing annealing process of bearing steel pipes, the production process of the bearing steel pipe comprises a capillary spheroidizing annealing process and a finished pipe destressing annealing process, and is characterized in that:
in the blank tube spheroidizing annealing process and the finished tube destressing annealing process, the carbon potential in the furnace is measured by a carbon potential meter, the ratio of natural gas to air in a DX gas generator is adjusted, and the carbon potential is controlled in a preset range;
wherein the carbon potential is controlled to be 1.00-1.05% in the capillary spheroidizing annealing process, and the carbon potential is controlled to be 1.00-1.05% in the finished product pipe stress relief annealing process.
2. The method for controlling DX gas carbon potential in the bearing steel tube anaerobic spheroidizing annealing process according to claim 1, characterized in that: the carbon potential is controlled to be 1.00% in the blank tube spheroidizing annealing process, and the carbon potential is controlled to be 1.00% in the finished product tube stress-relief annealing process.
3. The method for controlling DX gas carbon potential in the bearing steel tube anaerobic spheroidizing annealing process according to claim 1, characterized in that: the carbon potential is controlled to be 1.05% in the blank tube spheroidizing annealing process, and the carbon potential is controlled to be 1.05% in the finished product tube stress-relief annealing process.
4. The method for controlling DX gas carbon potential in the process of anaerobic spheroidizing annealing of bearing steel tube according to claim 2, characterized in that: in the capillary spheroidizing process, the furnace temperature is 790 ℃, the oxygen probe outputs 1118mv, and the heat preservation time is 11.5 h.
5. The method for controlling DX gas carbon potential in the process of anaerobic spheroidizing annealing of bearing steel tube according to claim 2, characterized in that: the temperature of the furnace in the finished product pipe stress-relief annealing process is 730 ℃, the output voltage of the oxygen probe is 1103mv, and the heat preservation time is 3.5 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110338594.7A CN113088662B (en) | 2021-04-30 | 2021-04-30 | DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110338594.7A CN113088662B (en) | 2021-04-30 | 2021-04-30 | DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113088662A true CN113088662A (en) | 2021-07-09 |
| CN113088662B CN113088662B (en) | 2023-03-28 |
Family
ID=76671125
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110338594.7A Active CN113088662B (en) | 2021-04-30 | 2021-04-30 | DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113088662B (en) |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5582729A (en) * | 1978-12-14 | 1980-06-21 | Kobe Steel Ltd | Heat treating method for steel material |
| US4497671A (en) * | 1982-02-01 | 1985-02-05 | Wasserman Gary L | Processed ferrous metal and process of production |
| JPH01165723A (en) * | 1987-12-21 | 1989-06-29 | Daido Steel Co Ltd | Bright annealing method for pipe coil and in-pipe purging device |
| JP2000045019A (en) * | 1998-07-27 | 2000-02-15 | Toyota Motor Corp | Decarburizing heat treatment of cast iron member |
| JP2006176863A (en) * | 2004-12-24 | 2006-07-06 | Aichi Steel Works Ltd | Steel for rolling bearing |
| CN102534138A (en) * | 2011-12-31 | 2012-07-04 | 海盐华辰工业炉有限公司 | Oxygen potential control system of spheroidizing annealing furnace |
| CN102626723A (en) * | 2012-04-17 | 2012-08-08 | 常熟市旋力轴承钢管有限公司 | Method for manufacturing steel pipe for bearing ring |
| CN102728652A (en) * | 2012-07-17 | 2012-10-17 | 新兴铸管股份有限公司 | Manufacturing method of dual-metal seamless steel pipe with outer-layer low-carbon steel and inner-layer bearing steel |
| CN102876858A (en) * | 2012-09-20 | 2013-01-16 | 洛阳鼎辉特钢制品股份有限公司 | Spheroidizing annealing process of GCr15 ball bearing steels based on severe-convection protective gas |
| CN106011425A (en) * | 2016-06-24 | 2016-10-12 | 邢台钢铁有限责任公司 | Hardening and tempering treatment technique for low-alloy heat-resistant steel fasteners |
| CN106636579A (en) * | 2016-12-12 | 2017-05-10 | 常熟市龙腾滚动体制造有限公司 | Manufacturing method of blank of bearing steel rolling body for wind driven generator yawing pitch bearing |
| JP2017133080A (en) * | 2016-01-29 | 2017-08-03 | Ｊｆｅスチール株式会社 | Oriented electromagnetic steel sheet and manufacturing method therefor |
| CN107345266A (en) * | 2017-08-02 | 2017-11-14 | 合肥市大卓电力有限责任公司 | A kind of Technology for Heating Processing of electrical steels |
| CN108913859A (en) * | 2018-07-03 | 2018-11-30 | 苏州中门子工业炉科技有限公司 | The application of DX atmosphere heat treatment furnace and high temperature alloy steel, high-carbon steel heat treatment |
-
2021
- 2021-04-30 CN CN202110338594.7A patent/CN113088662B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5582729A (en) * | 1978-12-14 | 1980-06-21 | Kobe Steel Ltd | Heat treating method for steel material |
| US4497671A (en) * | 1982-02-01 | 1985-02-05 | Wasserman Gary L | Processed ferrous metal and process of production |
| JPH01165723A (en) * | 1987-12-21 | 1989-06-29 | Daido Steel Co Ltd | Bright annealing method for pipe coil and in-pipe purging device |
| JP2000045019A (en) * | 1998-07-27 | 2000-02-15 | Toyota Motor Corp | Decarburizing heat treatment of cast iron member |
| JP2006176863A (en) * | 2004-12-24 | 2006-07-06 | Aichi Steel Works Ltd | Steel for rolling bearing |
| CN102534138A (en) * | 2011-12-31 | 2012-07-04 | 海盐华辰工业炉有限公司 | Oxygen potential control system of spheroidizing annealing furnace |
| CN102626723A (en) * | 2012-04-17 | 2012-08-08 | 常熟市旋力轴承钢管有限公司 | Method for manufacturing steel pipe for bearing ring |
| CN102728652A (en) * | 2012-07-17 | 2012-10-17 | 新兴铸管股份有限公司 | Manufacturing method of dual-metal seamless steel pipe with outer-layer low-carbon steel and inner-layer bearing steel |
| CN102876858A (en) * | 2012-09-20 | 2013-01-16 | 洛阳鼎辉特钢制品股份有限公司 | Spheroidizing annealing process of GCr15 ball bearing steels based on severe-convection protective gas |
| JP2017133080A (en) * | 2016-01-29 | 2017-08-03 | Ｊｆｅスチール株式会社 | Oriented electromagnetic steel sheet and manufacturing method therefor |
| CN106011425A (en) * | 2016-06-24 | 2016-10-12 | 邢台钢铁有限责任公司 | Hardening and tempering treatment technique for low-alloy heat-resistant steel fasteners |
| CN106636579A (en) * | 2016-12-12 | 2017-05-10 | 常熟市龙腾滚动体制造有限公司 | Manufacturing method of blank of bearing steel rolling body for wind driven generator yawing pitch bearing |
| CN107345266A (en) * | 2017-08-02 | 2017-11-14 | 合肥市大卓电力有限责任公司 | A kind of Technology for Heating Processing of electrical steels |
| CN108913859A (en) * | 2018-07-03 | 2018-11-30 | 苏州中门子工业炉科技有限公司 | The application of DX atmosphere heat treatment furnace and high temperature alloy steel, high-carbon steel heat treatment |
Non-Patent Citations (2)
| Title |
|---|
| 王锡樵;刘美冬;: "GCr15轴承套圈热处理探讨与分析" * |
| 耿树林: "《线材、小型棒材精整》", 30 April 1982, 冶金工业出版社 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113088662B (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6620262B1 (en) | Method of manufacturing inner and outer races of deep groove ball bearing in continuous annealing furnace | |
| CN103506380B (en) | A kind of production method reducing high-carbon barrel band practical decarburized depth | |
| US8047039B2 (en) | Process for producing stainless steel pipe | |
| CN114107626A (en) | Continuous spheroidizing annealing method for high-carbon chromium bearing steel round steel | |
| EP2025421B1 (en) | Process for producing seamless stainless-steel pipe | |
| CN110055381B (en) | Nitrogen protection annealing process of light-weight tool and die steel | |
| CA2217309C (en) | Method of manufacturing hot-worked elongated products, in particular bar or pipe, from high-alloy or hypereutectoid steel | |
| CN113088662B (en) | DX gas carbon potential control method in bearing steel pipe anaerobic spheroidizing annealing process | |
| JP3379345B2 (en) | Method for producing 13Cr stainless steel tube having oxide layer | |
| CN112779402B (en) | GCr15 bearing steel round steel annealing material and production method thereof | |
| CN114058951B (en) | 65Mn saw blade steel and preparation method thereof | |
| CN114164330A (en) | Heat treatment method of gear steel 20MnCr5 | |
| JPH03126858A (en) | Carburizing and heat treating method for high-carbon chromium bearing steel | |
| EP1795274A1 (en) | METHOD FOR HOT WORKING OF Cr-CONTAINING STEEL | |
| CN113083937B (en) | Production process of bearing steel pipe for cold-rolled expanded bearing | |
| CN109504894A (en) | A kind of clutch wide cut steel band and its manufacturing method | |
| JP2000001723A (en) | Bearing stock for cold rolling forming, and formed member thereof | |
| CN114273431B (en) | Method for reducing heating schedule of micro-alloy steel thermal cracks | |
| CN113088639B (en) | Bearing steel pipe inspection quality control method for cold rolling and expanding bearing | |
| CN113981186A (en) | Atmosphere protection heat treatment process for preventing decarbonization and recarburization | |
| CN117286315A (en) | Method for reducing thickness of decarburized layer of bar spring steel | |
| JP2002285233A (en) | Method for producing forged ring material for cold rolling forming | |
| US2184498A (en) | Manufacture of steel or alloy tubes | |
| CN109504893A (en) | A kind of band saw wide cut steel band and its manufacturing method | |
| CN117840250A (en) | Cooling control method for manufacturing seamless steel tube for bearing |
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 |