CN112375986A - Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof - Google Patents
Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof Download PDFInfo
- Publication number
- CN112375986A CN112375986A CN202011269006.0A CN202011269006A CN112375986A CN 112375986 A CN112375986 A CN 112375986A CN 202011269006 A CN202011269006 A CN 202011269006A CN 112375986 A CN112375986 A CN 112375986A
- Authority
- CN
- China
- Prior art keywords
- steel plate
- rolled
- less
- hot
- plastic die
- 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
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips 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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- 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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- 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
- C21D2211/002—Bainite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a hot-rolled and tempered pre-hardened plastic die steel plate and a production method thereof. The steel plate comprises the following components in percentage by weight: 0.32-0.42% of C, 0.2-0.4% of Si, 1.2-1.6% of Mn, 0.02-0.05% of Al, 1.5-1.8% of Cr, 0.15-0.25% of Mo, less than or equal to 0.02% of P, less than or equal to 0.005% of S, less than or equal to 0.005% of N, and the balance of iron and inevitable impurity elements. The production method comprises the steps of KR mechanical stirring desulfurization of molten iron, converter blow-curing smelting, LF refining, RH vacuum dehydrogenation treatment, continuous casting of a plate blank without oxidation protection, reheating of the plate blank, rolling, natural cooling, ultrasonic flaw detection and tempering. The steel plate has low cost, short delivery period and large production thickness specification, does not need normalizing or quenching heat treatment, can be directly tempered and then used for molding processing, and has wide application prospect.
Description
Technical Field
The invention relates to the field of ferrous metallurgy, in particular to a hot-rolled and tempered pre-hardened plastic die steel plate and a production method thereof.
Background
The plastic die steel is used as a forming die material for manufacturing plastic and rubber products, and is widely applied to manufacturing plastic products in various industries such as living appliances, transportation appliances and the like. The prior sand steel production plastic die steel plate is delivered in a thermal treatment state of quenching and tempering or normalizing and tempering, and the production flow is relatively complicated. The problems of quenching cracking, low core hardness and the like mainly exist in the production process, and meanwhile, the production cost is high, the production thickness is small, the delivery period is long, and the market development and the expansion of the sand steel plastic die steel plate are influenced.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the hot-rolled and tempered pre-hardened plastic die steel plate and the production method thereof, the steel plate has the advantages of good performance, low production cost, thick applicable thickness, short delivery period and the like, does not need heat treatment in the production process, can be directly used for die making processing, and has great popularization and application values.
In order to solve the problems of the prior art, the invention adopts the technical scheme that:
a hot-rolled and tempered pre-hardened plastic die steel plate comprises the following components in percentage by weight: 0.32-0.42% of C, 0.2-0.4% of Si, 1.2-1.6% of Mn, 0.02-0.05% of Al, 1.5-1.8% of Cr, 0.15-0.25% of Mo, less than or equal to 0.02% of P, less than or equal to 0.005% of S, less than or equal to 0.005% of N, and the balance of iron and inevitable impurity elements.
The improvement is that the thickness of the plastic die steel plate is less than or equal to 165mm, and the hardness is 28-34 HRC.
The production method of the hot-rolled and tempered pre-hardened plastic die steel plate comprises the steps of KR mechanical stirring desulfurization of molten iron, converter blow-curing smelting, LF refining, RH vacuum dehydrogenation treatment, continuous casting of a plate blank without oxidation protection, reheating of the plate blank, rolling, natural cooling, ultrasonic flaw detection and tempering.
The improvement is that after the KR molten iron is mechanically stirred and desulfurized, the KR molten iron enters a converter and the content of S in the KR molten iron is less than or equal to 0.005 percent.
The improvement is that the content of the molten steel S is less than or equal to 0.005 percent after the molten steel is treated by the converter oxygen blowing smelting and the LF refining furnace.
The improvement is that RH vacuum dehydrogenation treatment is carried out, the H content in the treated steel is less than 2ppm, and a calcium-silicon wire is fed after the treatment and is subjected to soft stirring for not less than 8 min.
The improvement is that the superheat degree of a tundish for continuous casting of the plate blank without oxidation protection is controlled at 20 +/-5 ℃, and the drawing speed is 0.6-0.7 m/min.
The improvement is that when the slab is reheated, the temperature is controlled to 1180-1250 ℃, and the furnace time is not less than 1.0 min/mm.
The improvement is that in the rolling stage, the blank is continuously rolled to the thickness of a finished product and the total pass rolling reduction with load and the pass rolling reduction are strictly controlled, an intermediate cooling function is used before the first pass and the last pass are rolled, the thickness is 120-165mm, the total pass is less than or equal to 5, and the single pass rolling reduction is up to 50 mm; naturally cooling the rolled steel plate on a cooling bed, wherein the offline temperature is less than 350 ℃, spreading and cooling the steel plate after the steel plate is offline, and the finishing and stacking temperature is less than 80 ℃.
The improvement is that the tempering temperature of the steel plate is controlled to be above 545 ℃ and the furnace time is 3.5 min/mm.
Has the advantages that:
compared with the prior art, the steel plate for the hot rolling and tempering pre-hardening plastic die and the production method thereof have important effects on reducing the production and manufacturing cost of the steel plate for the plastic die, shortening the delivery period, controlling the uniformity of performance and having large production thickness specification. The method does not need normalizing or quenching heat treatment, can be directly used for molding processing after tempering, and has wide application prospect. The concrete advantages are as follows:
(1) the content of alloy elements is strictly controlled, so that the alloy cost is more economic and saved;
(2) the process, the S content and the H content of the finished product are strictly controlled, the pure Ca wire is adopted for carrying out the deformation treatment of the inclusions, the soft stirring time is ensured to be not less than 8min, and the purity and the cleanliness of steel are ensured;
(3) the rolling process of the invention implements large reduction, namely, the reduction of a single pass in the rolling process is increased, and an intermediate cooling function is used for assisting before the first pass and the last pass are rolled, so that the deformation and the penetration to the core part of a casting blank are facilitated, and the internal quality is improved;
(4) the steel plate produced by the invention is naturally cooled on a cooling bed after being rolled, the offline temperature needs to be strictly controlled and needs to be less than 350 ℃. Spreading and cooling the steel plate after the steel plate is off-line, wherein the stacking temperature is lower than 80 ℃, and the cooling effect is ensured;
(5) the steel plate produced by the invention is directly tempered after rolling, quenching or normalizing heat treatment is not needed, and the production delivery period can be shortened. The tempering temperature of the steel plate is controlled to be above 545 ℃, the furnace time is 3.5min/mm, and the tempering effect and uniformity of the steel plate are ensured;
(6) the final structure of the hot-rolled and tempered pre-hardened plastic die steel plate is bainite, the hardness of the steel plate is 28-34HRC, the flaw detection of the steel plate meets the II-grade requirement in GB/T2970, and the performance meets the relevant standard and the use requirement of customers.
Drawings
FIG. 1 is a photograph of a typical structure of a 165mm hot rolled and tempered pre-hardened plastic die steel plate produced by the method of this patent.
Detailed Description
The process route is as follows: mechanical stirring and desulfurizing of molten iron KR, converter blow-maintaining smelting, LF refining, RH vacuum dehydrogenation treatment, continuous casting without oxidation protection of a plate blank, reheating of the plate blank, rolling, natural cooling, ultrasonic flaw detection and tempering.
In the embodiment, the smelting components of the smelting furnace are shown in Table 1, the control parameters of the rolling process are shown in Table 2, the control parameters of the heat treatment process are shown in Table 3, and the properties of the steel plate after heat treatment are shown in Table 4.
Table 1: EXAMPLES smelting compositions of smelting furnace
Table 2: examples Rolling Process control parameters
Table 3: example heat treatment process control parameters:
| examples | Thickness mm | Tempering temperature DEG C | In-furnace time min |
| Example 1 | 130 | 560 | 460 |
| Example 2 | 140 | 560 | 490 |
| Example 3 | 165 | 545 | 580 |
Table 4: examples properties of the Heat treated Steel sheets
The embodiments of the present invention show that the steel plate for hot rolling and tempering pre-hardening plastic mold and the production method thereof play an important role in reducing the production cost of the steel plate for plastic mold, shortening the delivery cycle, controlling the uniformity of performance, and increasing the production thickness specification.
The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any simple modifications or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention are within the scope of the present invention.
Claims (10)
1. The hot-rolled and tempered pre-hardened plastic die steel plate is characterized by comprising the following components in percentage by weight: 0.32-0.42% of C, 0.2-0.4% of Si, 1.2-1.6% of Mn, 0.02-0.05% of Al, 1.5-1.8% of Cr, 0.15-0.25% of Mo, less than or equal to 0.02% of P, less than or equal to 0.005% of S, less than or equal to 0.005% of N, and the balance of iron and inevitable impurity elements.
2. The hot rolled and tempered pre-hardened plastic die steel sheet as claimed in claim 1, wherein the thickness of the plastic die steel sheet is 120-165mm, and the hardness is 28-34 HRC.
3. The method for producing the hot-rolled and tempered pre-hardened plastic die steel plate as claimed in claim 1, wherein the production method comprises KR mechanical stirring desulfurization of molten iron, converter blow-maintaining smelting, LF refining, RH vacuum dehydrogenation treatment, continuous casting without oxidation protection of a plate blank, reheating of the plate blank, rolling, natural cooling, ultrasonic flaw detection and tempering.
4. The method for producing the hot-rolled and tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein the content of S in the molten iron KR in the converter after mechanical stirring and desulphurization is less than or equal to 0.005%.
5. The method for producing the hot-rolled and tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein the molten steel S content is less than or equal to 0.005% after the LF refining furnace treatment by oxygen blowing smelting and LF refining in the converter.
6. The method for producing a hot-rolled plus tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein RH vacuum dehydrogenation treatment is performed, the H content in the steel after treatment is less than 2ppm, and the steel after treatment is fed into a calcium-silicon wire and subjected to soft stirring for not less than 8 min.
7. A production method of a hot-rolled and tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein the superheat degree of a tundish for continuous casting without oxidation protection of a slab is controlled at 20 +/-5 ℃ and the drawing speed is 0.6-0.7 m/min.
8. A method for producing a hot-rolled plus tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein the slab is reheated at 1180 to 1250 ℃ for a period of not less than 1.0 min/mm.
9. The method for producing a hot-rolled and tempered pre-hardened plastic die steel plate as claimed in claim 3, wherein in the rolling stage, the blank is continuously rolled to the thickness of the finished product and the total pass and pass reduction under load are strictly controlled, the intermediate cooling function is used for the first pass and the last pass before rolling, the thickness is 120-165mm, the total pass is less than or equal to 5, and the single pass reduction is 50mm at most; naturally cooling the rolled steel plate on a cooling bed, wherein the offline temperature is less than 350 ℃, spreading and cooling the steel plate after the steel plate is offline, and the finishing and stacking temperature is less than 80 ℃.
10. A method for producing a hot rolled plus tempered pre-hardened plastic die steel sheet as claimed in claim 3, wherein the tempering temperature of the steel sheet is controlled to be over 545 ℃ and the in-furnace time is 3.5 min/mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011269006.0A CN112375986A (en) | 2020-11-13 | 2020-11-13 | Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011269006.0A CN112375986A (en) | 2020-11-13 | 2020-11-13 | Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112375986A true CN112375986A (en) | 2021-02-19 |
Family
ID=74582185
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011269006.0A Pending CN112375986A (en) | 2020-11-13 | 2020-11-13 | Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112375986A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113088633A (en) * | 2021-02-26 | 2021-07-09 | 舞阳钢铁有限责任公司 | Production method of Cr-Mo steel plate |
| CN113265575A (en) * | 2021-04-26 | 2021-08-17 | 五矿营口中板有限责任公司 | Preparation method of extra-thick Mn-Cr series die steel |
| CN113444867A (en) * | 2021-06-30 | 2021-09-28 | 江苏省沙钢钢铁研究院有限公司 | Production method of plastic die steel plate and plastic die steel plate |
| CN113564457A (en) * | 2021-06-25 | 2021-10-29 | 江苏沙钢集团有限公司 | Tempered and pre-hardened plastic die steel plate and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030131911A1 (en) * | 2001-04-17 | 2003-07-17 | Walter Grimm | Tool steel for plastic molds |
| JP2005171305A (en) * | 2003-12-10 | 2005-06-30 | Sanyo Special Steel Co Ltd | Prehardend die steel |
| CN102268599A (en) * | 2011-08-01 | 2011-12-07 | 南京钢铁股份有限公司 | Production technology of non-modulated plastic die steel thick plate |
| KR20140110720A (en) * | 2013-03-08 | 2014-09-17 | 두산중공업 주식회사 | Mold steel for die casting and hot stamping having the high thermal conductivity and method thereof |
| CN109252085A (en) * | 2017-07-13 | 2019-01-22 | 鞍钢股份有限公司 | A kind of production method of pre-hardening steel plate for plastic mould |
| CN110157981A (en) * | 2019-05-10 | 2019-08-23 | 南京钢铁股份有限公司 | Improve the production method of NSM30 plastic die steel section hardness uniformity |
-
2020
- 2020-11-13 CN CN202011269006.0A patent/CN112375986A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030131911A1 (en) * | 2001-04-17 | 2003-07-17 | Walter Grimm | Tool steel for plastic molds |
| JP2005171305A (en) * | 2003-12-10 | 2005-06-30 | Sanyo Special Steel Co Ltd | Prehardend die steel |
| CN102268599A (en) * | 2011-08-01 | 2011-12-07 | 南京钢铁股份有限公司 | Production technology of non-modulated plastic die steel thick plate |
| KR20140110720A (en) * | 2013-03-08 | 2014-09-17 | 두산중공업 주식회사 | Mold steel for die casting and hot stamping having the high thermal conductivity and method thereof |
| CN109252085A (en) * | 2017-07-13 | 2019-01-22 | 鞍钢股份有限公司 | A kind of production method of pre-hardening steel plate for plastic mould |
| CN110157981A (en) * | 2019-05-10 | 2019-08-23 | 南京钢铁股份有限公司 | Improve the production method of NSM30 plastic die steel section hardness uniformity |
Non-Patent Citations (3)
| Title |
|---|
| 余伟 等: "《热轧钢材的组织性能控制-原理、工艺与装备》", 31 October 2016 * |
| 张龙治等: "《重振雄风之路 应用高新技术改造传统产业研究•辽宁》", 28 February 1995 * |
| 萧忠敏: "《武钢 炼钢生产技术进步概况》", 31 December 2003 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113088633A (en) * | 2021-02-26 | 2021-07-09 | 舞阳钢铁有限责任公司 | Production method of Cr-Mo steel plate |
| CN113088633B (en) * | 2021-02-26 | 2023-03-21 | 舞阳钢铁有限责任公司 | Production method of Cr-Mo steel plate |
| CN113265575A (en) * | 2021-04-26 | 2021-08-17 | 五矿营口中板有限责任公司 | Preparation method of extra-thick Mn-Cr series die steel |
| CN113564457A (en) * | 2021-06-25 | 2021-10-29 | 江苏沙钢集团有限公司 | Tempered and pre-hardened plastic die steel plate and preparation method thereof |
| CN113444867A (en) * | 2021-06-30 | 2021-09-28 | 江苏省沙钢钢铁研究院有限公司 | Production method of plastic die steel plate and plastic die steel plate |
| CN113444867B (en) * | 2021-06-30 | 2022-09-20 | 江苏省沙钢钢铁研究院有限公司 | Production method of plastic die steel plate and plastic die steel plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112981235B (en) | Hardened and tempered steel plate with yield strength of 420MPa grade for building structure and production method thereof | |
| CN106119692B (en) | With the tensile strength >=1500MPa hot formings steel and production method of medium thin slab Direct Rolling | |
| CN110184525B (en) | High-strength Q500GJE quenched and tempered steel plate for building structure and manufacturing method thereof | |
| CN106086685B (en) | With the thin hot forming steel of tensile strength >=1500MPa of sheet billet Direct Rolling and production method | |
| CN112375986A (en) | Hot-rolled and tempered pre-hardened plastic die steel plate and production method thereof | |
| CN106119694B (en) | With the tensile strength >=1900MPa hot formings steel and production method of medium thin slab Direct Rolling | |
| CN109097699B (en) | 900 MPa-grade hot-rolled automobile girder steel and manufacturing method thereof | |
| CN111155028B (en) | Steel plate for normalized DH36 wind power and preparation method thereof | |
| CN104694822A (en) | High-strength hot rolled steel plate with 700 MPa grade yield strength and manufacturing method thereof | |
| CN109023111B (en) | 1000 MPa-grade hot-rolled automobile girder steel and manufacturing method thereof | |
| CN106119693B (en) | With the thin hot forming steel of tensile strength >=2100MPa of sheet billet Direct Rolling and production method | |
| CN114012056B (en) | 1500 MPa-level hot forming steel and preparation method thereof | |
| CN104805374A (en) | Q460E steel plate with thickness larger than 120 mm and manufacturing method of steel plate | |
| CN115181911B (en) | Super-thick Q500qE bridge steel plate and production method thereof | |
| CN112877586A (en) | Production method of high-strength and high-toughness American-standard steel rail for CR175 crane | |
| CN115125448A (en) | Non-quenched and tempered steel for cold machining of hydraulic piston rod and preparation method | |
| CN106086632B (en) | With the thin hot forming steel of tensile strength >=1100MPa of sheet billet Direct Rolling and production method | |
| CN102199734A (en) | High-strength 301L stainless steel used for bus, and manufacture method thereof | |
| CN110616301B (en) | Production method for improving precipitation strengthening effect of Ti microalloyed hot-rolled high-strength steel on line | |
| CN113549808A (en) | Production method of rare earth microalloyed Q355B low-alloy high-strength structural steel | |
| CN115261746B (en) | Super-thick Q420qE bridge steel plate and production method thereof | |
| CN115572912B (en) | Economical 460 MPa-level steel plate cooling uniformity control method for engineering structure | |
| CN103757533A (en) | Thin strip continuous casting economic high-strength binding strip with tensile strength of at least 1000 MPa and manufacturing method thereof | |
| CN110551949B (en) | Cold-rolled steel sheet for precisely stamping automobile safety belt buckle and manufacturing method thereof | |
| CN114000068B (en) | Low-nitrogen ultrahigh-strength hot-rolled steel strip with thickness of 4-10mm and production method thereof |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210219 |