CN112458256A - Annealing process of 1.2746 die steel of 45NiCrMoV or 4CrNi4MoV - Google Patents
Annealing process of 1.2746 die steel of 45NiCrMoV or 4CrNi4MoV Download PDFInfo
- Publication number
- CN112458256A CN112458256A CN202011200975.0A CN202011200975A CN112458256A CN 112458256 A CN112458256 A CN 112458256A CN 202011200975 A CN202011200975 A CN 202011200975A CN 112458256 A CN112458256 A CN 112458256A
- Authority
- CN
- China
- Prior art keywords
- annealing
- heating
- temperature
- speed
- cooling
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
-
- 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
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 Strip Materials And Filament Materials (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention provides an annealing process of 1.2746, namely 45NiCrMoV or 4CrNi4MoV die steel, which is realized by the following technical scheme. 1.2746(45NiCrMoV or 4CrNi4MoV) die steel is heated for homogenization time according to the effective thickness of the steel, and is subjected to austenite homogenization heating above Ar 1; austenitizing by using a continuous roller-hearth heating furnace, coarsening crystal grains, then slowly cooling to below an A1 line for annealing, then slowly cooling to below a martensite point, discharging and cooling to room temperature; then continuing to anneal at the annealing temperature, finally slowly cooling to the temperature below the martensite point, discharging and cooling to room temperature. The technical key points of the invention are as follows: after the second-stage annealing, the hardness is greatly reduced, and the austenitizing and annealing are proved to lay a good foundation for the second-stage annealing. The invention has the following advantages: on the premise of meeting the annealing hardness standard, the turnover time of the heat treatment furnace is shortened by one half, the equipment utilization rate is improved, and the energy-saving and environment-friendly effects are realized.
Description
Technical Field
The invention belongs to the technical field of metal heat treatment, and particularly relates to an annealing process of 1.2746(45NiCrMoV or 4CrNi4MoV) die steel.
Background
1.2746 pertains to an alloy tool steel of German standard, having the execution standard DIN EN ISO4957-2001, having the chemical composition (%) as: 0.41 to 0.49 percent of carbon, 0.15 to 0.35 percent of silicon, 0.60 to 0.80 percent of manganese, no more than 0.025 percent of phosphorus, no more than 0.020 percent of sulfur, 1.40 to 1.60 percent of chromium, 0.73 to 0.85 percent of molybdenum, 0.45 to 0.55 percent of vanadium, and the weight ratio of nickel: 3.80-4.20, which is equivalent to 45NiCrMoV or 4CrNi4MoV in China and belongs to cold-work die steel; the square flat steel or the round bar is used for cutting, the delivery state is usually delivered in an annealed state, the annealing Hardness (HBW) is not more than 295, and the target value is about 270. In the localization process, in order to realize the annealing Hardness (HBW) not more than 295, the annealing process of the same type of steel is mainly referred at present, the steel is annealed or pit-cooled, then heated to 630-680 ℃ at a temperature not more than 80 ℃/h, kept for 15-30 h, cooled to a temperature not more than 300 ℃ in a furnace at a temperature not more than 40 ℃/h, and then discharged, and if the hardness of the first annealing is not enough, the annealing is carried out again. But in order to make the hardness reach the standard in the actual production, the first annealing is carried out for 55-70 h at 680 ℃, the Hardness (HBW) is 320-341 and the hardness is not suitable after the annealing is discharged from a furnace; annealing is repeatedly carried out according to a planned annealing process system (shown in figure 1) until the hardness is qualified, secondary annealing is carried out, the temperature is maintained at 680 ℃ for 60-70 h, the Hardness (HBW) is 311-333 after secondary annealing is discharged from a furnace, and the hardness is still not qualified; and carrying out third annealing, keeping the temperature at 680 ℃ for 55-60 h, and testing the Hardness (HBW) after annealing out of the furnace to be about 274 so as to meet the requirement of delivery state. The heat preservation time of the process is as long as 200 hours, the total time length reaches 260 to 300 hours by adding the temperature rise and reduction time, the annealing time is long, the energy consumption is high, and the production efficiency and the equipment utilization rate are reduced.
Disclosure of Invention
The invention discloses an annealing process of 1.2746, namely 45NiCrMoV or 4CrNi4MoV die steel, and aims to solve the problem of long standard-reaching cycle of the annealing hardness of the die steel with high nickel and molybdenum contents.
The invention is realized by the following technical scheme. 1.2746, namely 45NiCrMoV or 4CrNi4MoV die steel is heated for homogenization time according to the effective thickness of the steel, austenite homogenization heating is carried out above Ar1, a continuous roller-hearth heating furnace is adopted for austenitizing, crystal grains are coarsened, then the temperature is slowly reduced to be below the A1 line for annealing, and then the temperature is slowly cooled to be below the martensite point and then is discharged from the furnace and cooled to room temperature; then continuing to anneal at the annealing temperature, finally slowly cooling to the temperature below the martensite point, discharging and cooling to room temperature.
The specific process (as shown in fig. 2) comprises the following steps:
the method comprises the steps of heating steel in a continuous roller-bottom heating furnace or a bell-type heating furnace by adopting a combustible medium or electricity at a heating speed of not more than 100 ℃/h to 730-780 ℃ for austenitizing and preserving heat for 4-8 h;
after the heat preservation is finished, slowly cooling to 630-680 ℃ at the speed of not more than 40 ℃/h for annealing, after the heat preservation is carried out for 20-36 h, slowly cooling to not more than 250 ℃ at the speed of 40 ℃/h, discharging and cooling to the room temperature;
thirdly, the steel is heated by adopting combustible media or electricity in a continuous roller-hearth heating furnace or a bell-type heating furnace, the heating speed is not more than 100 ℃/h, the steel is heated to 630-680 ℃ for annealing, the temperature is kept for 20-36 h, then the steel is slowly cooled to not more than 250 ℃ at the speed of 40 ℃/h, and then the steel is taken out of the furnace and cooled to the room temperature.
Hardness of steel after each annealing:
austenitizing the steel, and then continuously annealing to obtain a steel product with a Hardness (HBW) of 310-414;
and annealing the steel for the second time to obtain the steel with the Hardness (HBW) of 260-280.
The technical key points of the invention are as follows:
after the first section of annealing is finished, although the hardness of the steel is equivalent to that of the original process, after the second section of annealing is carried out, the hardness reduction range is large, and the result proves that the first section of austenitizing and annealing process lays a good foundation for the second section of annealing.
The invention has the following advantages:
on the premise of ensuring that the annealing hardness meets the requirement, the turnover time of the heat treatment furnace is shortened by one half, the equipment utilization rate is improved, and the energy-saving and environment-friendly effects are achieved.
Drawings
FIG. 1 is a heat treatment process curve of a conventional process;
figure 2 is a graph of an annealing process of the present invention.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
Example 1
1.2746 flat steel, size 60mm thickness, 120mm width, 6.0m length, weight 16.8 tons. After the steel is taken out of the pit, measuring Hardness (HBW)410, 425 and 435;
carrying out first annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 780 ℃ and keeping the temperature for 8 h; after the heat preservation is finished, slowly cooling to 680 ℃ at the speed of 35 ℃/h, preserving the heat for 25h, slowly cooling to 250 ℃ at the speed of 35 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 370, 386, 410.
And carrying out secondary annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 630 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, slowly cooling to 250 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 270, 276, 280.
Example 2
1.2746 flat steel, measuring 58mm in thickness, 118mm in width, 6.0m in length and weighing 13.7 tons. After the steel is taken out of the pit, the Hardness (HBW)414, 432 and 438 are measured;
carrying out first annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 780 ℃ and keeping the temperature for 8 h; after the heat preservation is finished, slowly cooling to 650 ℃ at the speed of 40 ℃/h, preserving the heat for 25h, slowly cooling to 230 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 375, 382, 414.
And carrying out secondary annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 630 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, slowly cooling to 240 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 268, 270, 275.
Example 3
1.2746 flat steel, measuring 44mm in thickness, 110mm in width, 6.0m in length and weighing 12.6 tons. After the steel is taken out of the pit, measuring the Hardness (HBW)411, 430 and 437;
carrying out first annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 740 ℃ and keeping the temperature for 6 h; after the heat preservation is finished, slowly cooling to 650 ℃ at the speed of 40 ℃/h, preserving the heat for 30h, slowly cooling to 225 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 380, 388, 410.
And carrying out secondary annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 650 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, slowly cooling to 210 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; the test Hardness (HBW) was 266, 269, 275.
Claims (4)
1. An annealing process of 1.2746 die steel of 45NiCrMoV or 4CrNi4MoV, which is characterized in that: the specific process steps are as follows:
the method comprises the steps of heating steel in a continuous roller-bottom heating furnace or a bell-type heating furnace by adopting a combustible medium or electricity at a heating speed of not more than 100 ℃/h to 730-780 ℃ for austenitizing and preserving heat for 4-8 h;
after the heat preservation is finished, slowly cooling to 630-680 ℃ at the speed of not more than 40 ℃/h for annealing, after the heat preservation is carried out for 20-36 h, slowly cooling to not more than 250 ℃ at the speed of 40 ℃/h, discharging and cooling to the room temperature;
thirdly, heating the steel in a continuous roller hearth heating furnace or a bell-type heating furnace by adopting coal gas or electricity, heating at the temperature rising speed of not more than 100 ℃/h, annealing at the temperature of 630-680 ℃, keeping the temperature for 20-36 h, slowly cooling to the temperature of not more than 250 ℃ at the speed of 40 ℃/h, discharging and cooling to the room temperature.
2. The 1.2746 NiCrMoV or 4CrNi4MoV die steel annealing process of claim 1, wherein: the annealing process comprises the following steps of: heating combustible media in a continuous roller hearth heating furnace at the heating rate of 80 ℃/h to 780 ℃ and preserving heat for 8 h; after the heat preservation is finished, slowly cooling to 680 ℃ at the speed of 35 ℃/h, preserving the heat for 25h, slowly cooling to 250 ℃ at the speed of 35 ℃/h, discharging and cooling to room temperature; and (3) second annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 630 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, the temperature is slowly cooled to 250 ℃ at the speed of 30 ℃/h, and then the product is taken out of the furnace and cooled to the room temperature.
3. The 1.2746 NiCrMoV or 4CrNi4MoV die steel annealing process of claim 1, wherein: the annealing process comprises the following steps of: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 780 ℃ and keeping the temperature for 8 h; after the heat preservation is finished, slowly cooling to 650 ℃ at the speed of 40 ℃/h, preserving the heat for 25h, slowly cooling to 230 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; and (3) second annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 630 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, the temperature is slowly cooled to 240 ℃ at the speed of 30 ℃/h, and then the product is taken out of the furnace and cooled to the room temperature.
4. The 1.2746 NiCrMoV or 4CrNi4MoV die steel annealing process of claim 1, wherein: the annealing process comprises the following steps of: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 740 ℃ and keeping the temperature for 6 h; after the heat preservation is finished, slowly cooling to 650 ℃ at the speed of 40 ℃/h, preserving the heat for 30h, slowly cooling to 225 ℃ at the speed of 30 ℃/h, discharging and cooling to room temperature; and (3) second annealing: heating with coal gas in a continuous roller hearth heating furnace at a heating rate of 80 ℃/h to 650 ℃ and keeping the temperature for 36 h; after the heat preservation is finished, the temperature is slowly cooled to 210 ℃ at the speed of 30 ℃/h, and then the product is taken out of the furnace and cooled to the room temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011200975.0A CN112458256B (en) | 2020-11-02 | 2020-11-02 | 1.2746 (45 NiCrMoV or 4CrNi4 MoV) die steel annealing process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011200975.0A CN112458256B (en) | 2020-11-02 | 2020-11-02 | 1.2746 (45 NiCrMoV or 4CrNi4 MoV) die steel annealing process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112458256A true CN112458256A (en) | 2021-03-09 |
| CN112458256B CN112458256B (en) | 2022-10-14 |
Family
ID=74835697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011200975.0A Active CN112458256B (en) | 2020-11-02 | 2020-11-02 | 1.2746 (45 NiCrMoV or 4CrNi4 MoV) die steel annealing process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112458256B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06322439A (en) * | 1993-05-06 | 1994-11-22 | Kobe Steel Ltd | Method for softening and annealing high alloy tool steel |
| CN1609238A (en) * | 2004-09-17 | 2005-04-27 | 宝钢集团上海五钢有限公司 | Softening annealing heat treating method for 1Cr17Ni2 stainless steel |
| CN1614038A (en) * | 2004-09-29 | 2005-05-11 | 宝钢集团上海五钢有限公司 | Softening treatment of moderate alloy nickle serial cold working mold steel |
| CN105714308A (en) * | 2014-12-05 | 2016-06-29 | 重庆永林机械设备有限公司 | Novel heat treatment technology of 0Cr4NiMoV die steel |
| CN110257601A (en) * | 2019-07-12 | 2019-09-20 | 河冶科技股份有限公司 | The secondary ultra-soft spheroidizing method of high speed steel |
| CN110628999A (en) * | 2019-10-24 | 2019-12-31 | 成都先进金属材料产业技术研究院有限公司 | Softening method of forged steel for large-specification rock drilling tool |
-
2020
- 2020-11-02 CN CN202011200975.0A patent/CN112458256B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06322439A (en) * | 1993-05-06 | 1994-11-22 | Kobe Steel Ltd | Method for softening and annealing high alloy tool steel |
| CN1609238A (en) * | 2004-09-17 | 2005-04-27 | 宝钢集团上海五钢有限公司 | Softening annealing heat treating method for 1Cr17Ni2 stainless steel |
| CN1614038A (en) * | 2004-09-29 | 2005-05-11 | 宝钢集团上海五钢有限公司 | Softening treatment of moderate alloy nickle serial cold working mold steel |
| CN105714308A (en) * | 2014-12-05 | 2016-06-29 | 重庆永林机械设备有限公司 | Novel heat treatment technology of 0Cr4NiMoV die steel |
| CN110257601A (en) * | 2019-07-12 | 2019-09-20 | 河冶科技股份有限公司 | The secondary ultra-soft spheroidizing method of high speed steel |
| CN110628999A (en) * | 2019-10-24 | 2019-12-31 | 成都先进金属材料产业技术研究院有限公司 | Softening method of forged steel for large-specification rock drilling tool |
Non-Patent Citations (2)
| Title |
|---|
| 李伟: "1Cr12Ni3Mo2VN退火工艺研究", 《特钢技术》 * |
| 杨钢等: "1Cr12Ni3Mo2VN耐热钢退火工艺研究", 《钢铁研究学报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112458256B (en) | 2022-10-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109554621B (en) | Low-density Fe-Mn-Al-C hot-rolled Q & P steel and manufacturing method thereof | |
| CN103866095B (en) | A kind of spheroidizing method for being directed to Cr, Mo steel with sheet microstructure | |
| CN102925657A (en) | Rolling deformation quenching composite reinforcing method of middle carbon alloyed steel bearing ring piece | |
| CN113652607A (en) | 1000 MPa-grade quenched and tempered steel plate for hydroelectric power generation and production method thereof | |
| CN109852880A (en) | A kind of high heat-intensity hot-work die steel and its manufacturing method | |
| CN109252107B (en) | Production method of high-flatness ultrahigh-strength steel | |
| CN106854733B (en) | A kind of manufacturing process of 14Cr17Ni2 stainless steels heavy forging | |
| CN105506249A (en) | Heat treatment method for high-nitrogen corrosion resistant plastic die steel | |
| CN113817967A (en) | Hot-delivery hot-charging production method for reducing depth of decarburized layer of bearing steel round steel | |
| CN102041371A (en) | Heat treatment method of high-tenacity high-strength steel plate | |
| CN102766818B (en) | Martensite steel based on dynamic carbon partitioning principle | |
| CN110760653B (en) | Control method for preventing bearing steel from decarbonizing | |
| CN105154793A (en) | High-strength high-corrosion-resistance double-phase heat resistant steel | |
| CN110756616A (en) | Preparation method for reducing high-carbon martensitic stainless steel pipe | |
| CN103993233A (en) | Novel high-service life die-casting mold steel and process method for manufacturing aluminum-magnesium die-casting mold | |
| CN105177445A (en) | Preparation method for high-toughness 3.5Ni steel plate | |
| CN112458256B (en) | 1.2746 (45 NiCrMoV or 4CrNi4 MoV) die steel annealing process | |
| CN101736139B (en) | Organization control method of large-size pre-hardening type plastic die steel module | |
| CN103993141A (en) | Spheroidizing annealing process for high-toughness medium carbon steel wires | |
| CN103451557A (en) | Tungsten and molybdenum composite strengthened high-cobalt nickel and high-toughness secondary hardened ultrahigh-strength steel | |
| CN103045958A (en) | High-strength steel plate used at low temperature of subzero 50 DEG C and preparation method thereof | |
| CN103643167B (en) | A kind of working method of 700MPa level Green heat treatment high strength cast iron | |
| CN102181787B (en) | Refractory corrosion-resisting steel as well as preparation and heat treatment method thereof | |
| CN102808128A (en) | Method for improving high temperature yield strength of low-carbon steel plate for pressure equipment | |
| CN111020147B (en) | Rolling production method of electric slag finished steel plate for nuclear power flywheel |
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 |