CN115287441B - Post-welding heat treatment method for U71MnG high-speed steel rail welding joint - Google Patents
Post-welding heat treatment method for U71MnG high-speed steel rail welding joint Download PDFInfo
- Publication number
- CN115287441B CN115287441B CN202210912903.1A CN202210912903A CN115287441B CN 115287441 B CN115287441 B CN 115287441B CN 202210912903 A CN202210912903 A CN 202210912903A CN 115287441 B CN115287441 B CN 115287441B
- Authority
- CN
- China
- Prior art keywords
- joint
- welding
- steel rail
- air
- u71mng
- 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
- 238000003466 welding Methods 0.000 title claims abstract description 93
- 238000010438 heat treatment Methods 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 18
- 229910000997 High-speed steel Inorganic materials 0.000 title claims abstract description 9
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 51
- 239000010959 steel Substances 0.000 claims abstract description 51
- 238000001816 cooling Methods 0.000 claims abstract description 35
- 238000005507 spraying Methods 0.000 claims description 26
- 239000010953 base metal Substances 0.000 claims description 11
- 238000005485 electric heating Methods 0.000 claims description 4
- 230000006698 induction Effects 0.000 claims description 3
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 238000007550 Rockwell hardness test Methods 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000035882 stress Effects 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- QFXZANXYUCUTQH-UHFFFAOYSA-N ethynol Chemical group OC#C QFXZANXYUCUTQH-UHFFFAOYSA-N 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006355 external stress Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
- C21D9/505—Cooling thereof
-
- 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
- C21D1/34—Methods of heating
- C21D1/42—Induction heating
-
- 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
- C21D1/34—Methods of heating
- C21D1/52—Methods of heating with flames
-
- 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
-
- 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
-
- 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
- Y02P10/25—Process efficiency
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a post-welding heat treatment method of a U71MnG high-speed steel rail welding joint, which comprises the steps of heating a welding joint welding line area of the U71MnG steel rail welding joint cooled to below 300 ℃ after butt welding to 880-910 ℃, stopping heating, adopting air-jet cooling, stopping air-jet cooling after the tread temperature of the steel rail joint is reduced to 410-455 ℃, and naturally cooling to room temperature; the air pressure of the air-jet cooling air-jet is 0.03+/-0.01 MPa. The heat treatment method provided by the invention can effectively improve the hardness of the steel rail welding joint, ensure the normal structure morphology of the steel rail welding joint and improve the reduced performance state.
Description
Technical Field
The invention belongs to the technical field of steel rail welding, and particularly relates to a post-welding heat treatment method of a U71MnG high-speed steel rail welding joint.
Background
The performance of the steel rail flash welding head is mainly influenced by welding defects, welding machine states and steel rail parent metals, and is also influenced by postweld heat treatment. The biggest difference between domestic steel rail flash welding and foreign steel rail flash welding is whether to perform welding joint normalizing heat treatment. The foreign hot rolled steel rail is not subjected to postweld heat treatment, but only the heat treated steel rail is subjected to postweld heat treatment, and all steel rail flash welding heads are required to be subjected to postweld normalizing heat treatment in China. The width of the welding heat affected zone of the foreign hot rolled steel rail flash welding head is narrower, and the upper width and the lower width are consistent. The weld metallographic grain size is coarse, and the austenite grain boundary formed by ferrite net is used for analyzing the grain size only about 1 grade. The whole joint of domestic flash welding needs to be subjected to normalizing heat treatment. Because the heat treatment needs to cover the original flash welding head heat affected zone, the heat affected heating width is obviously larger than the welding state heat affected zone width. The main is that after the steel rail flash welding seam is heat treated, the metal microstructure is obviously refined, the grain size is improved from 1 level to more than 8 levels, and the toughness of the steel rail flash welding joint is well improved. After the welding line is heat treated, the plasticity and toughness of the steel rail flash welding head are greatly improved. This is because the heat treatment greatly refines the weld grains, reduces the solid solubility of carbon in the alloy, and thus greatly improves the toughness of the welded joint of the steel rail. Therefore, the post-welding heat treatment process of the welding joint has very important significance for improving the quality of the high-speed steel rail.
The steel rail welding has the characteristics of high heating temperature, high heating speed, short high-temperature residence time, uneven temperature distribution, continuous cooling under the air cooling condition and the like, and is easy to generate coarse structure in joints, especially heat affected zones, so that the hardness is reduced, even harmful structures such as martensite are easy to form, and the phenomena of hardening, embrittlement and the like are caused at the joints; meanwhile, the welded joint generates internal stress, and is extremely easy to break under the action of complex external stress, so that the welded joint becomes a weak link for line operation. In order to release the stress, refine the grains, change the joint structure morphology, improve the reduced performance state, post-weld heat treatment of the rail joints is required.
Disclosure of Invention
In order to solve one or more problems in the prior art, one aspect of the present invention provides a post-weld heat treatment method for a U71MnG high-speed rail welded joint, which includes heating a U71MnG rail welded joint weld region cooled to 300 ℃ or below after butt welding to 880-910 ℃, stopping heating, cooling by air-spraying, stopping air-spraying cooling after the tread temperature of the rail joint is reduced to 410-455 ℃, and naturally cooling to room temperature; the air pressure of the air-jet cooling air-jet is 0.03+/-0.01 MPa; wherein the weld joint area refers to the area within 20mm of each of the two sides of the welding line.
In some embodiments, the air-cooled starting joint tread temperature is controlled between 745-810 ℃.
In some embodiments, the heating mode of the welding seam area of the U71MnG high-speed rail welding joint is double induction electric heating or oxyacetylene flame heating.
In some embodiments, the heating time of the welding line area of the U71MnG high-speed rail welding joint is controlled to be 100-190s.
In some embodiments, the air jet cooled air jet is 20±5mm from the rail joint surface.
The post-welding heat treatment method for the U71MnG high-speed steel rail welding joint based on the technical scheme improves the hardness of the U71MnG steel rail welding joint by controlling the heating temperature, the air blowing pressure and the final cooling temperature, so that the ratio K 1 of the average hardness H J of the welding joint to the average hardness H P of the base metal meets that K 1 is more than or equal to 1.10 and more than or equal to 0.95; the ratio K 2 of the soft spot hardness average value H J1 of the welding joint to the base metal hardness average value H P is more than or equal to 0.80; the softening area is smaller than 20mm, and meets the standard requirement. In addition, the method of the invention effectively controls the hardness of the steel rail welding joint, ensures the normal structure form of the steel rail welding joint and improves the reduced performance state. The method has good popularization and application prospects, and can be popularized and used in domestic high-speed rail welding bases or online welding construction units.
Drawings
FIG. 1 is a graph of the post weld heat treatment profile hardness of the U71MnG rail of example 1.
FIG. 2 is a graph of the post weld heat treatment profile hardness of the U71MnG rail of example 2.
FIG. 3 is a graph of the post weld heat treatment profile hardness of the U71MnG rail of example 3.
Detailed Description
The invention aims to solve the problems that the hardness of a welded joint is low and abnormal structures such as martensite are generated due to the fact that the local cooling speed of the welded joint of a steel rail is higher than the critical transition temperature in the cooling process.
The invention solves the technical problems by adopting a technical scheme that a post-welding heat treatment method of a U71MnG steel rail welding joint is provided. The method comprises the following steps: cooling to below 300 ℃ in U71MnG steel rail welding joint weld joint area (refers to the area within 20mm on each side of the welding line), heating to 880-910 ℃, stopping heating, cooling by air spraying, stopping air spraying cooling after the tread temperature of the steel rail joint is reduced to 410-455 ℃, and naturally cooling to room temperature; the wind pressure of the air is 0.03+/-0.01 MPa, and can be selected to be 0.035+/-0.005 MPa.
In the post-welding heat treatment method of the U71MnG steel rail welding joint, a double-induction electric heating or oxyacetylene flame heating mode is adopted for heating the welding joint welding seam area of the U71MnG steel rail welding joint. The heating time of the welding joint area of the U71MnG steel rail is controlled to be 100-190s. The temperature of the tread of the initial joint cooled by air spraying is controlled to be 745-810 ℃, and the distance between the air spraying opening cooled by air spraying and the surface of the steel rail joint is 20+/-5 mm.
In the invention, the welded joint area of the U71MnG steel rail welded joint which is cooled to below 300 ℃ after butt welding is heated to 880-910 ℃, then the heating is stopped, and the normalizing process is adopted to effectively control the hardness of the steel rail joint, simultaneously, the joint stress is released, the joint grains are refined, the joint structure form is changed, and the reduced performance state is improved. When the surface of the rail head of the steel rail reaches the required range, but the interior of the steel rail possibly does not reach the required temperature, the temperature cannot be too low in order to ensure that the temperature of the core can reach the required temperature; when the temperature is too high, the temperature at the rail bottom of the relatively thin steel rail is higher than the actual measured temperature, and the risk of tissue overheating exists, on the other hand, the heating coil is a source of heat, heat is conducted to the two ends of the steel rail by taking the heating coil as the center, the width of a heat affected zone can be widened, and even the standard requirement is not met.
In the present invention, the final cooling temperature should be controlled between 410 and 455 ℃. The final cooling temperature is too high to meet the hardness requirement; the final cooling temperature is too low, and the rail joints can generate martensite abnormal structures. In the post-welding heat treatment method of the U71MnG steel rail welding joint, the welding joint area of the U71MnG steel rail welding joint is heated by adopting double induction electric heating, firstly, low-frequency 1000-1500Hz frequency is adopted, the heating time is 60-100s at 820+/-10 ℃, and then high-frequency 2000-2500Hz at 880+/-10 ℃ is adopted, and the heating time is 60-100s.
The following describes the invention in detail by way of specific examples, which are intended to aid in understanding the invention and are not intended to limit the invention.
Example 1
The welding joint area of the U71MnG steel rail is heated by adopting a double-frequency heating mode, firstly, the welding joint area is heated by adopting low-frequency 1450Hz frequency at 820 ℃ for 72s, and then is heated by adopting high-frequency 2100Hz at 880 ℃ for 75s. Heating was stopped after reaching 910 ℃. After heating is stopped, when the tread temperature of the rail joint is reduced to 798 ℃, air-spraying cooling is carried out, the air-spraying opening is 22mm away from the surface of the rail joint, the air-spraying pressure is 0.03MPa, when the tread temperature of the joint is reduced to 425 ℃, air-spraying cooling is stopped, and then the rail joint is naturally cooled to room temperature. The hardness of 5mm Rockwell on the tread of the rail head on the longitudinal section was measured by using an HR-150A Rockwell hardness tester with reference to the TB/T1632.2-2014 standard. As a result, as shown in Table 1 below, in this example, the ratio K 1 of the average hardness H J of the heat-treated joint after welding to the average hardness H P of the base material of the steel rail of 60kg/m U71/MnG was 1.02, the ratio K 2 of the average hardness H J1 of the soft spot of the welded joint to the average hardness H P of the base material was 0.89, the width of the softened region on the left side of the joint was 12.0mm, and the width of the softened region on the right side was 9.0mm, and the standard requirements were satisfied.
TABLE 1
The hardness curve is drawn on a graph by using Rockwell hardness test data of each measuring point of a rail head (a test line 1 in fig. 1) on a longitudinal section of a welded joint, the width of a welding line with the hardness value lower than 0.9H p is taken as the width of a softening area and recorded as W, the standard requirement W is less than or equal to 20mm, and the test result is shown in fig. 1.
Example 2
The welding joint area of the U71MnG steel rail is heated by adopting a double-frequency heating mode, firstly, the welding joint area is heated by adopting a low-frequency 1250Hz frequency at 825 ℃ for 67s, and then is heated by adopting a high-frequency 2380Hz at 890 ℃ for 90s. Heating was stopped after reaching 900 ℃. After heating is stopped, when the tread temperature of the rail joint is reduced to 760 ℃, air-spraying cooling is carried out, the air-spraying opening is 23mm away from the surface of the rail joint, the air-spraying pressure is 0.04MPa, when the tread temperature of the joint is reduced to 455 ℃, air-spraying cooling is stopped, and then the rail joint is naturally cooled to room temperature. The hardness of 5mm Rockwell on the tread of the rail head on the longitudinal section was measured by using an HR-150A Rockwell hardness tester with reference to the TB/T1632.2-2014 standard. As a result, as shown in Table 2 below, in this example, the ratio K 1 of the average hardness H J of the heat-treated joint after welding to the average hardness H P of the base metal of the steel rail of 60kg/m U71/MnG was 1.06, the welded joint had no soft spot hardness, the width of the softened region on the left side of the joint was 15.0mm, and the width of the softened region on the right side was 13.0mm, and the standard requirements were satisfied.
TABLE 2
The hardness curve is drawn on a graph by using Rockwell hardness test data of each measuring point of a rail head (a test line 1 in fig. 2) on a longitudinal section of a welded joint, the width of a hardness value lower than 0.9Hp is respectively used as the width of a softening area at two sides of a welding seam, the width is marked as W, the standard requirement W is less than or equal to 20mm, and the test result is shown in fig. 2.
Example 3
The welding joint area of the U71MnG steel rail is heated by adopting a double-frequency heating mode, firstly, the welding joint area is heated by adopting low-frequency 1280Hz frequency at 830 ℃ for 80s, and then is heated by adopting high-frequency 2492Hz at 885 ℃ for 81s. Heating was stopped after reaching 880 ℃. After heating is stopped, when the tread temperature of the rail joint is reduced to 750 ℃, air-jet cooling is carried out, the air-jet opening is 20mm away from the surface of the rail joint, the air-jet pressure is 0.035MPa, when the tread temperature of the joint is reduced to 410 ℃, air-jet cooling is stopped, and then the rail joint is naturally cooled to room temperature. The hardness of 5mm Rockwell on the tread of the rail head on the longitudinal section was measured by using an HR-150A Rockwell hardness tester with reference to the TB/T1632.2-2014 standard. As a result, as shown in Table 3 below, in this example, the ratio K 1 of the average hardness H J of the heat-treated joint after welding to the average hardness H P of the base material of the steel rail of 60kg/m U71/MnG was 1.01, the ratio K 2 of the average hardness H J1 of the soft spot of the joint to the average hardness H P of the base material of the steel rail was 0.88, the width of the softened region on the left side of the joint was 12.0mm, and the width of the softened region on the right side was 13.0mm, and the standard requirements were satisfied.
TABLE 3 Table 3
The hardness curve is drawn on a graph by using Rockwell hardness test data of each measuring point of a rail head (a test line 1 in fig. 3) on a longitudinal section of a welded joint, the width of a hardness value lower than 0.9Hp is respectively used as the width of a softening area at two sides of a welding seam, the width is marked as W, the standard requirement W is less than or equal to 20mm, and the test result is shown in fig. 3.
Comparative example 1
The welding joint area of the U71MnG steel rail is heated by adopting a double-frequency heating mode, firstly, the welding joint area is heated by adopting low-frequency 1450Hz frequency at 820 ℃ for 72s, and then is heated by adopting high-frequency 2100Hz at 880 ℃ for 75s. Heating was stopped after 865 ℃. After heating is stopped, when the tread temperature of the rail joint is reduced to 798 ℃, air-spraying cooling is carried out, the air-spraying opening is 22mm away from the surface of the rail joint, the air-spraying pressure is 0.2MPa, when the tread temperature of the joint is reduced to 460 ℃, air-spraying cooling is stopped, and then the rail joint is naturally cooled to room temperature. The hardness of 5mm Rockwell on the tread of the rail head on the longitudinal section was measured by using an HR-150A Rockwell hardness tester with reference to the TB/T1632.2-2014 standard. In the comparative example, the ratio K 1 of the hardness average value H J and the base metal hardness average value H P of the heat treatment joint after steel rail welding of 60kg/m U71MnG is 0.90, the ratio K 2 of the soft point hardness average value H J1 and the base metal hardness average value H P of the welding joint is 0.79, the width of the softening area at the left side of the joint is 13.0mm, the width of the softening area at the right side of the joint is 11.0mm, and the standard requirement is not met.
Comparative example 2
The welding joint area of the U71MnG steel rail is heated by adopting a double-frequency heating mode, firstly, the welding joint area is heated by adopting low-frequency 1450Hz frequency at 820 ℃ for 72s, and then is heated by adopting high-frequency 2100Hz at 880 ℃ for 75s. Heating was stopped after reaching 915 ℃. After heating is stopped, when the tread temperature of the rail joint is reduced to 798 ℃, air-spraying cooling is carried out, the air-spraying opening is 22mm away from the surface of the rail joint, the air-spraying pressure is 0.05MPa, when the tread temperature of the joint is reduced to 430 ℃, air-spraying cooling is stopped, and then the rail joint is naturally cooled to room temperature. The hardness of 5mm Rockwell on the tread of the rail head on the longitudinal section was measured by using an HR-150A Rockwell hardness tester with reference to the TB/T1632.2-2014 standard. In the comparative example, the ratio K 1 of the hardness average value H J of the heat treatment joint after welding of the steel rail of 60kg/m U71MnG to the hardness average value H P of the base metal is 0.91, the ratio K 2 of the hardness average value H J1 of the soft points of the welding joint to the hardness average value H P of the base metal is 0.77, the width of the softening area on the left side of the joint is 12.0mm, the width of the softening area on the right side of the joint is 15.5mm, and the standard requirement is not met.
It can be seen that the above examples 1-3 all have good hardness of the welded joint of the rail, and the ratio K 1 of the average hardness H J of the joint to the average hardness H P of the base metal satisfies 1.10.gtoreq.K 1.gtoreq.0.95, preferably 1.10.gtoreq.K 1.gtoreq.1.00; the ratio K 2 of the joint soft spot hardness average value H J1 to the base metal hardness average value H P is more than or equal to 0.80, preferably K 2 is more than or equal to 0.85, and further preferably K 2 is more than or equal to 0.88; the softening area is smaller than 20mm, and meets the standard requirement. The hardness of the welded joint of the rail obtained by the heat treatment method of comparative examples 1 to 2 above is not satisfactory.
Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the technical solutions described in the foregoing embodiments, or that equivalents may be substituted for part of the technical features thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (1)
1. A post-welding heat treatment method for a U71MnG high-speed steel rail welding joint is characterized by comprising the steps of heating a welding joint welding line area of the U71MnG steel rail welding joint cooled to below 300 ℃ after butt welding to 880-910 ℃, stopping heating, cooling by adopting air spraying, stopping cooling by the air spraying after the tread temperature of the steel rail joint is reduced to 410-455 ℃, and naturally cooling to room temperature; the distance between the air outlet of the air-jet cooling device and the surface of the steel rail joint is 20+/-5 mm, and the air pressure of the air-jet cooling device is 0.03+/-0.01 MPa; wherein the weld joint area refers to an area within 20mm of each of two sides of the welding line; wherein:
The welding joint area of the U71MnG high-speed steel rail is heated by adopting double induction electric heating, firstly, the low-frequency 1000-1500Hz frequency is adopted, the heating time is 60-100s, then the high-frequency 2000-2500Hz is adopted, the heating time is 880+ -10 ℃ and the heating time is 60-100s; the temperature of the tread of the initial joint cooled by air spraying is controlled to be 745-810 ℃;
the ratio K 1 of the average hardness H J of the U71MnG high-speed steel rail welded joint after heat treatment to the average hardness H P of the base metal meets 1.10-1. 1; the ratio K 2 of the soft spot hardness average value H J1 of the welding joint to the base metal hardness average value H P is more than or equal to 0.88.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210912903.1A CN115287441B (en) | 2022-07-31 | 2022-07-31 | Post-welding heat treatment method for U71MnG high-speed steel rail welding joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210912903.1A CN115287441B (en) | 2022-07-31 | 2022-07-31 | Post-welding heat treatment method for U71MnG high-speed steel rail welding joint |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115287441A CN115287441A (en) | 2022-11-04 |
| CN115287441B true CN115287441B (en) | 2024-04-30 |
Family
ID=83825787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210912903.1A Active CN115287441B (en) | 2022-07-31 | 2022-07-31 | Post-welding heat treatment method for U71MnG high-speed steel rail welding joint |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115287441B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115896438A (en) * | 2022-11-28 | 2023-04-04 | 包头钢铁（集团）有限责任公司 | Heat treatment method for welded joint for improving quality of U71MnH steel rail |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012028111A1 (en) * | 2010-09-02 | 2012-03-08 | 攀钢集团有限公司 | Steel rail for high speed and quasi-high speed railways and manufacturing method thereof |
| CN109022746A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The heat treatment method of U71MnH rail flash welding connector |
| CN109022748A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The heat treatment method of U71MnH steel rail weld joint |
| CN109022749A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of U71MnH steel rail weld joint |
| CN109022747A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of U71MnH rail flash welding connector |
| CN110343841A (en) * | 2019-07-30 | 2019-10-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Groove-shape rail flash welding connector post weld heat treatment method |
-
2022
- 2022-07-31 CN CN202210912903.1A patent/CN115287441B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012028111A1 (en) * | 2010-09-02 | 2012-03-08 | 攀钢集团有限公司 | Steel rail for high speed and quasi-high speed railways and manufacturing method thereof |
| CN109022746A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The heat treatment method of U71MnH rail flash welding connector |
| CN109022748A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The heat treatment method of U71MnH steel rail weld joint |
| CN109022749A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of U71MnH steel rail weld joint |
| CN109022747A (en) * | 2018-10-24 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of U71MnH rail flash welding connector |
| CN110343841A (en) * | 2019-07-30 | 2019-10-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Groove-shape rail flash welding connector post weld heat treatment method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115287441A (en) | 2022-11-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109022748B (en) | Heat treatment method of U71MnH steel rail welded joint | |
| CN109022746B (en) | Heat treatment method of U71MnH steel rail flash welding joint | |
| CN109022747B (en) | Postweld heat treatment method for U71MnH steel rail flash welding joint | |
| CN104946870A (en) | Heat treatment method for strength of 28CrMoNiV steel capable of improving industrial steam turbine rotor forge piece | |
| CN104862466A (en) | Method for postweld heat treatment on hyper-eutectoid steel rail welding connector | |
| JP2016538417A (en) | Non-tempered steel and manufacturing method thereof | |
| CN115287441B (en) | Post-welding heat treatment method for U71MnG high-speed steel rail welding joint | |
| CN102658417A (en) | Welding repair technology of casting defect of high-chromium cast iron | |
| US20190106761A1 (en) | Rail of railway with passenger and freight mixed traffic and manufacturing method thereof | |
| CN109570368A (en) | A method of preparing ultra-high strength steel hot stamping forming die | |
| CN114507772A (en) | Heat treatment process for high-strength and high-toughness bainite steel rail welded joint for heavy haul railway | |
| CN109022749B (en) | Postweld heat treatment method for U71MnH steel rail welding joint | |
| JPH01190907A (en) | Remolten chilled camshaft | |
| JP5326343B2 (en) | Manufacturing method of high internal hardness rail | |
| KR101242688B1 (en) | Laser welding method of silicon steel | |
| CN109136762A (en) | A kind of semitrailer welding I beam steel and its production method | |
| AU2018247225B2 (en) | High-toughness and plasticity hypereutectoid rail and manufacturing method thereof | |
| CN115287442A (en) | Postweld heat treatment method for high-carbon microalloyed steel rail | |
| JP5979373B2 (en) | Manufacturing method of ERW steel pipe with excellent low temperature toughness | |
| CN111187883B (en) | Method for solving problem of high local hardness of cast iron casting after weld repair | |
| CN116240357A (en) | Heat treatment method of flash welding head of 60kg/m U VH steel rail | |
| CN110480141A (en) | The technique for controlling lower limit Mn content R350HT rail flash welding joint microstructure | |
| CN117660736A (en) | Heat treatment method for 350HB grade steel rail welded joint | |
| CN116287658A (en) | Method for heat treatment of welded joint of 75kg/m U75VH steel rail | |
| CN115896437A (en) | Heat treatment method for improving hardness of U71MnG steel rail welding joint |
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 |