CN117949316A - Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet - Google Patents
Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet Download PDFInfo
- Publication number
- CN117949316A CN117949316A CN202311742076.7A CN202311742076A CN117949316A CN 117949316 A CN117949316 A CN 117949316A CN 202311742076 A CN202311742076 A CN 202311742076A CN 117949316 A CN117949316 A CN 117949316A
- Authority
- CN
- China
- Prior art keywords
- temperature
- continuous casting
- shaped steel
- sm490yb
- sample
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 31
- 239000010959 steel Substances 0.000 title claims abstract description 31
- 238000009749 continuous casting Methods 0.000 title claims abstract description 29
- 238000002474 experimental method Methods 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000004088 simulation Methods 0.000 claims abstract description 16
- 238000001816 cooling Methods 0.000 claims abstract description 12
- 238000004519 manufacturing process Methods 0.000 claims abstract description 8
- 239000002436 steel type Substances 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 abstract description 5
- 238000012545 processing Methods 0.000 abstract description 4
- 238000012360 testing method Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 238000005266 casting Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Continuous Casting (AREA)
Abstract
The invention discloses an experimental method for determining the optimal straightening temperature of a continuous casting blank of H-shaped steel of an SM490YB ocean engineering series, which comprises the steps of processing the H-shaped steel with higher crack rate and corresponding production batch into a thermal simulation high-temperature tensile sample, heating the sample to 1300 ℃ at the speed of 10 ℃/s, preserving heat for 180s, cooling to the experimental temperature at the speed of 3 ℃/s, preserving heat for 120s, then breaking the sample at the speed of 0.1mm/s, measuring the area shrinkage rate of all the samples, finding the sample with the highest area shrinkage rate, and obtaining the corresponding experimental temperature as the optimal straightening temperature; the continuous casting process can lead the temperature of the special-shaped blank to reach the required temperature for straightening by reasonably adjusting the drawing speed of the special-shaped continuous casting blank and the cooling speed of the secondary cooling zone, thereby reducing the generation rate of cracks.
Description
Technical Field
The invention relates to the technical field of steel making, in particular to an experimental method for determining the optimal straightening temperature of a continuous casting blank of H-shaped steel of an SM490YB ocean engineering series.
Background
SM490YB belongs to a series of H-shaped steel for ocean engineering, has four common specifications of H700 x 300mm, H588 x 300mm, H440 x 300mm and H300 x 30mm respectively, has a composition range (see table 1), belongs to microalloy high-strength steel, has a delivery state requiring yield strength of more than 355MPa, has a tensile strength of 490-610 MPa, has a ton steel profit of more than 1000 yuan, and is a typical high-added-value product; however, because the H-shaped steel is special of the special-shaped continuous casting blank, microcracks with different degrees are common at the 'R' -angle of the web plate and the connection part of the web plate and the flange, wherein microcracks at the transverse and longitudinal directions of the web plate are all shown, the microcracks at the R-angle are mainly longitudinal cracks, the crack ratio of the casting blank is generally about 10-20% in actual production, the crack ratio can be reduced to about 3% by carrying out manual flame cleaning on the crack, and the aim of the process is to avoid the crack from further expanding in the downstream rolling process and influencing the yield of products; in fact, the crack rate of almost all specifications of H-shaped steel is still maintained to be about 10% after the H-shaped steel is heated, rolled, cooled and straightened by a downstream heating furnace, and the crack is still required to be removed by means of polishing and the like; thus, the production period is prolonged, the production cost is increased, and the profit margin of the product is further compressed. Through metallographic analysis, oxidation dots and decarburization exist around cracks, but crystal grains do not grow obviously, and the cracks are generated in a straightening link of continuous casting with high probability. The metal material has three high-temperature brittle areas in 800-1200 deg.c, and the brittle areas may have obvious difference with the change of material composition, and the straightening temperature of the special blank may avoid the brittle areas and lower the crack rate of the casting blank. It is therefore the meaning of the present invention how to determine the optimum straightening temperature of H-steel of different composition.
Disclosure of Invention
The invention aims to provide an experimental method for determining the optimal straightening temperature of a continuous casting blank of SM490YB ocean engineering series H-shaped steel, and aims to determine the optimal straightening temperature of the SM490YB belonging to ocean engineering series H-shaped steel, so that the generation rate of straightening cracks in the continuous casting process is effectively reduced.
In order to solve the technical problems, the invention adopts the following technical scheme:
The invention relates to an experimental method for determining the optimal straightening temperature of a continuous casting blank of H-shaped steel of an SM490YB ocean engineering series, which comprises the steps of processing the H-shaped steel with higher crack rate and corresponding production batch into a thermal simulation high-temperature tensile sample, heating the sample to 1300 ℃ at the speed of 10 ℃/s, preserving heat for 180s, cooling to the experimental temperature at the speed of 3 ℃/s, preserving heat for 120s, then pulling the sample at the speed of 0.1mm/s, measuring the area shrinkage rate of all the samples, finding the sample with the highest area shrinkage rate, and obtaining the corresponding experimental temperature as the optimal straightening temperature; the continuous casting process can lead the temperature of the special-shaped blank to reach the required temperature for straightening by reasonably adjusting the drawing speed of the special-shaped continuous casting blank and the cooling speed of the secondary cooling zone, thereby reducing the generation rate of cracks.
Further, the H-shaped steel special-shaped blank with cracks is sampled and processed into a thermal simulation high-temperature tensile sample with the specification of phi 10mm multiplied by 110mm, wherein the steps at the two ends have the dimensions of phi 12mm multiplied by 2mm.
Further, the test sample is suitable for being used in MMS-200 type thermal simulation experiment machines.
Further, the continuous casting billet comprises the following chemical components in percentage by mass: c is less than or equal to 0.18; si is less than or equal to 0.50; mn0.9-1.6; p is less than or equal to 0.025; s is less than or equal to 0.025; nb is less than or equal to 0.05; v is less than or equal to 0.10; the balance of Fe and unavoidable impurities.
Furthermore, the steel type SM490YB has the maximum surface shrinkage at 950 ℃ and the minimum surface shrinkage at 1000 ℃, so the optimal straightening temperature of the H-shaped steel for the SM490YB ocean engineering in the component system is 950 ℃, and the special-shaped blank is strictly forbidden to be straightened at 1000 ℃.
Compared with the prior art, the invention has the beneficial technical effects that:
Measuring the area shrinkage of all the samples by the method, finding out the sample with the highest area shrinkage, and obtaining the corresponding experimental temperature as the optimal straightening temperature; the continuous casting process can lead the temperature of the special-shaped blank to reach the required temperature for straightening by reasonably adjusting the drawing speed of the special-shaped continuous casting blank and the cooling speed of the secondary cooling zone, thereby reducing the generation rate of cracks.
Drawings
The invention is further described with reference to the following description of the drawings.
FIG. 1 is a thermal modeling experiment regime;
FIG. 2 is a thermal simulation high temperature tensile specimen of MMS-200 model.
Detailed Description
An experimental method for determining the optimal straightening temperature of a continuous casting blank of an SM490YB ocean engineering series H-shaped steel comprises the following steps:
(1) Sampling, namely sampling on an H-shaped steel special-shaped blank with cracks, processing the H-shaped steel special-shaped blank into a thermal simulation high-temperature tensile sample with the specification of phi 10mm multiplied by 110mm, wherein the step sizes at two ends are phi 12mm multiplied by 2mm, (the specifications of the thermal simulation test samples of different models of thermal simulation test machines are different), and the specifications of the sample are shown in figure 2, so that the thermal simulation test machine is applicable to an MMS-200 type thermal simulation test machine.
(2) And (3) performing a thermal simulation experiment, welding a thermocouple at the center of a sample by using a spot welder (see figure 2), opening a setting program at an upper computer of the thermal simulation experiment machine, inputting experimental parameters, heating the sample to 1300 ℃ at a heating rate of 10 ℃/s, preserving heat for 180 seconds, cooling to the experimental temperature at a rate of 3 ℃/s (see table 2), preserving heat for 120 seconds, and breaking the sample at a rate of 0.1 mm/s.
(3) And (3) data processing and analysis, namely respectively measuring the surface rates of the samples under different temperature systems, finding out the experimental temperature corresponding to the sample with the maximum surface shrinkage as the optimal straightening temperature, wherein the scheme corresponds to the steel type SM490YB, and has the maximum surface shrinkage at 950 ℃ and the minimum surface shrinkage at 1000 ℃, so that the optimal straightening temperature of the H-shaped steel for SM490YB ocean engineering under the component system is 950 ℃ and the special-shaped blank is strictly forbidden to be straightened at 1000 ℃.
(4) The control of the on-site production process and the verification of the method prove that the cold speed of the secondary cooling zone of continuous casting and the drawing speed of the continuous casting blank can be reasonably configured during on-site production, the continuous casting blank for experiments is straightened at 950 ℃, the web plate and the R angle crack rate of the special-shaped continuous casting blank for experiments are observed to be lower than 3%, and the method can determine the optimal straightening temperature of the H-shaped steel for SM490YB ocean engineering.
Table 1 SM490YB chemical composition unit: %
TABLE 2 thermal simulation experiment temperatures and experimental results
| Sample numbering | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| Experimental temperature (. Degree. C.) | 800 | 850 | 900 | 950 | 1000 | 1050 | 1100 | 1150 | 1200 | 1250 | 1300 |
| Area shrinkage (%) | 96.4 | 96 | 87 | 92.7 | 56 | 83.2 | 85.6 | 87.8 | 98 | 67.5 | 57.8 |
The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.
Claims (5)
1. An experimental method for determining the optimal straightening temperature of a continuous casting blank of H-shaped steel of an SM490YB ocean engineering series is characterized in that H-shaped steel with higher crack rate and corresponding production batch is processed into a thermal simulation high-temperature tensile sample, the sample is heated to 1300 ℃ at the speed of 10 ℃/s and is kept at the temperature for 180 seconds, then is cooled to the experimental temperature at the speed of 3 ℃/s, after being kept at the temperature for 120 seconds, the sample is broken at the speed of 0.1mm/s, the area shrinkage rate of all the samples is measured, the sample with the highest area shrinkage rate is found, and the corresponding experimental temperature is the optimal straightening temperature; the continuous casting process can lead the temperature of the special-shaped blank to reach the required temperature for straightening by reasonably adjusting the drawing speed of the special-shaped continuous casting blank and the cooling speed of the secondary cooling zone, thereby reducing the generation rate of cracks.
2. The experimental method for determining the optimal straightening temperature of the continuous casting blank of the SM490YB ocean engineering series H-shaped steel according to claim 1, wherein the H-shaped steel special-shaped blank with cracks is sampled and processed into a thermal simulation high-temperature tensile sample with the specification of phi 10mm multiplied by 110mm, and the steps at two ends have the dimensions of phi 12mm multiplied by 2mm.
3. The experimental method for determining the optimal straightening temperature of the continuous casting blank of the SM490YB ocean engineering series H-shaped steel according to claim 2, wherein the sample is applicable to an MMS-200 type thermal simulation experiment machine.
4. The experimental method for determining the optimal straightening temperature of the continuous casting blank of the SM490YB ocean engineering series H-shaped steel according to claim 1, wherein the continuous casting blank comprises the following chemical components in percentage by mass: c is less than or equal to 0.18; si is less than or equal to 0.50; mn 0.9-1.6; p is less than or equal to 0.025; s is less than or equal to 0.025; nb is less than or equal to 0.05; v is less than or equal to 0.10; the balance of Fe and unavoidable impurities.
5. The experimental method for determining the optimal straightening temperature of the continuous casting blank of the SM490YB ocean engineering series H-shaped steel, as set forth in claim 4, is characterized in that the steel type SM490YB has the maximum surface shrinkage at 950 ℃ and the minimum surface shrinkage at 1000 ℃, so that the optimal straightening temperature of the H-shaped steel for the SM490YB ocean engineering in the component system is 950 ℃ and the special-shaped blank is strictly forbidden to be straightened at 1000 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311742076.7A CN117949316A (en) | 2023-12-18 | 2023-12-18 | Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311742076.7A CN117949316A (en) | 2023-12-18 | 2023-12-18 | Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117949316A true CN117949316A (en) | 2024-04-30 |
Family
ID=90797357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311742076.7A Pending CN117949316A (en) | 2023-12-18 | 2023-12-18 | Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117949316A (en) |
-
2023
- 2023-12-18 CN CN202311742076.7A patent/CN117949316A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104525560A (en) | Effective control method for pitted surface of plain carbon steel/Nb-containing steel plate of 20-30 mm thickness | |
| EP0787541A1 (en) | Method of manufacturing seamless steel pipes and manufacturing equipment therefor | |
| CN102628148A (en) | Acid-washing hot-rolled low-carbon steel without line defects on surface and production method thereof | |
| CN104894485A (en) | Production method of nuclear power plant used high-temperature-resisting brittleness-resisting seamless steel tube with outer diameter of more than 508mm | |
| CN111215567A (en) | Forging method for improving grain size of GH4099 high-temperature alloy thin-wall ring | |
| CN106636747A (en) | Manufacturing method for producing commercial pure titanium plate by adopting double annealing of heavy and medium plate mill | |
| CN109468561A (en) | A kind of preparation method of GH3625 alloy strip steel rolled stock | |
| CN111575450A (en) | Seamless steel pipe and preparation method thereof | |
| CN108330386B (en) | Steel for saw blade and production method of hot rolled steel plate thereof | |
| CN103753116B (en) | The manufacture method of sendzimir mill working roll | |
| CN107201436A (en) | A kind of process for producing Thin Specs medium carbon steel | |
| CN104625607B (en) | Glisten weld-ring INCO718 process for making profiles | |
| CN117949316A (en) | Experiment method for determining optimal straightening temperature of SM490YB ocean engineering series H-shaped steel continuous casting billet | |
| CN108555202A (en) | A kind of manufacturing method of the embedded pin flat bar of diameter forging machine production core grade driving mechanism | |
| CN113549746B (en) | Forging and heat treatment process of steel for 20MnMo tube plate | |
| CN113953426A (en) | Manufacturing method of high-toughness mining wear-resistant steel ball | |
| CN108396125A (en) | A kind of processing technology of carburizing steel railway bearing forging crystal grain refinement | |
| CN111974812B (en) | Production method of super-thick steel plate | |
| CN111534759B (en) | Processing method for improving end cracking of high-hardenability steel after annealing | |
| CN112941410A (en) | Method for controlling alpha phase content in austenitic stainless steel | |
| CN113290045A (en) | Rolling process for improving bending of CrMo round steel | |
| CN112763508A (en) | Method for judging cause of edge cracking crack of medium plate | |
| CN114602994B (en) | Preparation method of cold-work hardened stainless steel bar | |
| CN105256242A (en) | Manufacturing method for forge piece blanks for marine oil exploitation equipment | |
| CN112893467A (en) | Method for controlling edge folding of wide and thick steel plate |
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 |