CN112195326A - Deep cooling process for strengthening performance of tool and die steel - Google Patents
Deep cooling process for strengthening performance of tool and die steel Download PDFInfo
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- CN112195326A CN112195326A CN202011033407.6A CN202011033407A CN112195326A CN 112195326 A CN112195326 A CN 112195326A CN 202011033407 A CN202011033407 A CN 202011033407A CN 112195326 A CN112195326 A CN 112195326A
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- tool
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- 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
- C21D6/04—Hardening by cooling below 0 degrees Celsius
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- 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
- C21D1/06—Surface hardening
- C21D1/09—Surface hardening by direct application of electrical or wave energy; by particle radiation
- C21D1/10—Surface hardening by direct application of electrical or wave energy; by particle radiation by electric induction
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- 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
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/32—Soft annealing, e.g. spheroidising
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F13/00—Apparatus or processes for magnetising or demagnetising
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- 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
Abstract
The invention provides a method for processing a tool and a die by subzero treatment, which comprises the steps of normalizing or spheroidizing annealing, magnetization, surface chemical treatment, subzero treatment, tempering and demagnetization, the process avoids the performance difference caused by different tool and die materials or different original heat treatment states, the surface is a high-hardness infiltrated layer, the hardness can reach about 2000-3200, the service life is prolonged by several times due to the improvement of the hardness, the tool and the die have extremely high wear resistance, occlusion resistance, corrosion resistance and other performances, the coating is compact and smooth, and can be processed repeatedly for many times by combining with matrix metallurgy; the core has good toughness, the whole structure is uniformly refined, good wear resistance is ensured in the using process, and meanwhile, the red hardness is good, the long-time construction can be carried out under the condition of poor cooling, the service life of the workpiece can be prolonged by several times to tens of times, and the service value is extremely high.
Description
Technical Field
The invention relates to the technical field of tool and die processing, in particular to a deep cooling process for strengthening the performance of tool and die steel.
Background
Metal cutting is one of the mainstream processing methods in the machine manufacturing industry, most parts with high requirements on dimensional accuracy and surface quality need to be subjected to cutting, and the level of cutting technology (including cutting methods, tools, dies, processing techniques and the like) plays a significant role in processing accuracy, product quality, productivity and production cost, especially the characteristics of used cutting tools and dies. Through cost accounting, the cost consumed by a cutting tool and a die generally accounts for 5-10% of the manufacturing cost of the product, and the production cost caused by the indirect influence of the tool and the die, such as shutdown loss caused when a machine tool is shut down, the maintenance man-hour of the die, the treatment cost of cooling lubricating liquid and the like, accounts for a larger proportion of the manufacturing cost. Therefore, the wear resistance and the stability of the material of the tool and the die are enhanced, the service life of the material of the tool and the die can be prolonged to a certain extent, and the breakage rate of the tool and the die is reduced, so that the effects of increasing the cutting amount, reducing the auxiliary working time and reducing the production cost can be achieved.
The cryogenic treatment is usually liquid nitrogen cooling, which can cool the workpiece to below-190 ℃. The microstructure of the processed material is changed in a low-temperature environment, and certain properties are improved. The cryogenic treatment was studied in the united states since the 50 s of the 20 th century, mainly for the field of aviation, with the 70 s extending to the field of mechanical manufacture.
The biggest current problem of cryogenic treatment is unstable service life of tools and dies. The deep cooling treatment can improve the cutting life of the tool and the die from 20 times, 10 times, several times to tens of percent, and reports that the tool life is not improved or even reduced exist. The reason why the cryogenic treatment effect shows great difference is complex, and the method has close relation with the original heat treatment state of the tool before cryogenic treatment, and also has relation with a plurality of factors such as the specific conditions of cryogenic treatment and the like.
Disclosure of Invention
There is a need for a cryogenic process that enhances the properties of tool and die steel.
A deep cooling process for strengthening the performance of tool and die steel comprises the following steps:
s1, normalizing or spheroidizing annealing the tool and die steel to eliminate the defect of forged structure;
s2, carrying out magnetization treatment on the annealed tool and die steel;
s3, carrying out surface chemical treatment on the tool and die steel subjected to the magnetization treatment;
s4, carrying out deep cooling treatment on the magnetized tool and die;
s5, tempering the tool and the die after the deep cooling treatment;
and S6, carrying out demagnetization treatment on the tempered tool and die.
Preferably, the tool steel in step S1 is one of T8, T10, 9CrSi, Cr12MoV, D2, high speed steel, YT-based, YC-based, and YG-based cemented carbide.
Preferably, the magnetization treatment is circumferential magnetization, longitudinal magnetization or multidirectional magnetization, and the magnetic field intensity of the magnetization is 1-500 KA/m.
Preferably, the surface treatment is one or more of boronizing, siliconizing and high-frequency treatment.
Preferably, the cryogenic treatment medium is liquid nitrogen, and the temperature is-100 to-196 ℃.
Preferably, the tempering temperature is 150-650 ℃, and the time is 1-48 h.
Preferably, the demagnetization treatment adopts an alternating current demagnetization method or a direct current demagnetization method, and the sample is completely demagnetized.
The method for treating the tool and the die by subzero treatment avoids the performance difference caused by different tool and die materials or different original heat treatment states, the surface is a high-hardness seeping layer, the Hardness (HV) can reach about 2000-3200, the service life is prolonged by multiple times due to the improvement of the hardness, the tool and the die have extremely high wear resistance, seizure resistance, corrosion resistance and other properties, the coating is compact and smooth, and can be subjected to repeated treatment for many times by being combined with the matrix metallurgy; the core has good toughness, the whole structure is uniformly refined, good wear resistance is ensured in the using process, and meanwhile, the red hardness is good, the long-time construction can be carried out under the condition of poor cooling, the service life of the workpiece can be prolonged by several times to tens of times, and the service value is extremely high.
The tool and the die obtained by the process method have good dimensional stability. Because the martensite is completely transformed in the cryogenic treatment process under the low-temperature environment of-100 to-196 ℃, the content of the retained austenite is effectively reduced, the aging deformation or the size change caused by the retained austenite in the use process is avoided, and the requirement on machining allowance is low.
Detailed Description
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.
Example 1
S1, carrying out normalizing or spheroidizing annealing treatment on the die steel 9CrSi, namely heating the 9CrSi steel piece to 810 ℃, preserving heat for 2 hours and then air-cooling; and then heating the 9CrSi steel piece to 780 ℃, preserving heat for 4 hours, and then cooling the steel piece to room temperature along with the furnace. The process can eliminate coarse pearlite structure in forging, refine grains rapidly and prepare the structure for the subsequent heat treatment process.
And S2, carrying out circumferential magnetization treatment on the annealed steel piece, wherein the magnetic field intensity of magnetization is 350 KA/m.
S3, carrying out surface boronizing and high-frequency quenching treatment on the magnetized steel piece, wherein the boronizing temperature is 1050 ℃. The process effectively improves the surface wear resistance of the steel part. After magnetization treatment, the crystal grains are refined, and the preparation of structure for surface treatment is made
S4, carrying out subzero treatment on the steel piece after the surface treatment, wherein the treatment equipment is an SLX-250 ultra-deep cold box, the medium is liquid nitrogen, the temperature is-150 ℃, and the heat preservation time is 24 h.
And S5, tempering after cryogenic treatment to eliminate residual stress and stabilize the structure, wherein the tempering temperature is 200 ℃ and the tempering time is 4 hours.
And S6, carrying out complete demagnetization treatment on the steel piece by adopting an alternating current demagnetization method. The phase change reaction is more thorough after the cryogenic treatment, the retained austenite is less, and the structure is stable.
Example 2
As a control test, the T10 test piece of the die steel 9CrSi was subjected to the following three treatments (A, B, C), respectively, and the treated test piece was subjected to a comparative test with the treated test piece of the example under the conditions of a test force of 20N and a test time of 5min, respectively (FIG. 1); 40N, 10min (FIG. 2); 60N, 15min (figure 3), and the rotating speed is 180 r/min.
A. Spheroidizing annealing + quenching + tempering (this treatment process is only the steps S1, S3 high frequency quenching, S5 in example 1)
B. Spheroidizing annealing, quenching, deep cooling and tempering (the treatment process only adopts the steps of S1 and S3 in the example 1, and the steps of S4 and S5)
C. Spheroidizing annealing, magnetization, quenching, deep cooling and tempering (the treatment process only adopts the steps of high-frequency quenching, S4 and S5 in S1, S2 and S3 in example 1)
Fig. 1, 2 and 3 are wear graphs generated by comparing the A, B, C three sets of processes with the process of example 1 and testing the wear resistance. As can be seen, the wear of the test piece of example 1 is much lower than that of the other three sets of data, and the wear resistance and hence the life of the test piece are multiplied.
Example 3
Respectively carrying out microscopic metallographic observation on the test blocks treated by the process A by 500 times, wherein the pictures of the surface structures of the test blocks are shown in figure 4. The sample treated by the process of example 1 was subjected to metallographic observation by a microscope at 500 × a, and the picture of the surface structure thereof is shown in fig. 5, and the picture of the core structure thereof is shown in fig. 6.
As is clear from fig. 4, 5 and 6, the structure in the process a is an acicular martensite structure. The surface of example 1 was a fine, dispersed carbide, which was metallurgically bonded to the base material and had a dense structure and a fine acicular martensite structure as the core. The die is applied to the stamping and forming production of the bearing seat, the number of workpieces stamped at one time is increased to about 12 thousands, the service life is prolonged by nearly 10 times, the die can completely replace a hard alloy stamping die, and the production cost is effectively reduced.
Example 4
The 4 groups of test block materials were subjected to impact test detection by a JBN-300 type impact tester. Rectangular unnotched specimens having a test specimen size of 10mm × 10mm × 55mm were examined.
The impact performance test results are shown in table 1 below:
TABLE 1 impact test results of 9CrSi test block treated by different processes
| Process numbering | A | B | C | Example 1 |
| Impact work/J | 9 | 6 | 4 | 3.5 |
| Impact toughness/J.cm-2 | 91.30 | 60.96 | 40.45 | 35.30 |
Table 1 shows the impact toughness of the A, B, C three sets of processes compared to the process of example 1. As can be seen from the data in the table, the impact toughness of the process test block in example 1 is the best, which is much lower than that of the other three groups of data, because the magnetization treatment and the cryogenic treatment can play a role in refining grains, thereby reducing the impact toughness of the workpiece.
The modules or units in the device of the embodiment of the invention can be combined, divided and deleted according to actual needs.
The above disclosure is only illustrative of the preferred embodiments of the present invention, which should not be taken as limiting the scope of the invention, but rather the invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It will be understood by those skilled in the art that all or a portion of the above-described embodiments may be practiced and equivalents thereof may be resorted to as falling within the scope of the invention as claimed. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may include only a single embodiment, and such description is for clarity only, and those skilled in the art will be able to make the description as a whole, and the embodiments may be suitably combined to form other embodiments as will be apparent to those skilled in the art.
Claims (7)
1. A deep cooling process for strengthening the performance of tool and die steel is characterized by comprising the following steps:
s1, normalizing or spheroidizing annealing the tool and die steel to eliminate the defect of forged structure;
s2, carrying out magnetization treatment on the annealed tool and die steel;
s3, carrying out surface chemical treatment on the tool and die steel subjected to the magnetization treatment;
s4, carrying out deep cooling treatment on the magnetized tool and die;
s5, tempering the tool and the die after the deep cooling treatment;
and S6, carrying out demagnetization treatment on the tempered tool and die.
2. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein the tool and die steel in step S1 is one of T8, T10, 9CrSi, Cr12MoV, D2, high speed steel, YT, YC, YG type cemented carbide.
3. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein: the magnetization treatment is circumferential magnetization, longitudinal magnetization or multidirectional magnetization, and the magnetic field intensity of magnetization is 1-500 KA/m.
4. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein: the surface treatment is one or more of boronizing, siliconizing and high-frequency treatment.
5. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein: the cryogenic treatment medium is liquid nitrogen, and the temperature is-100 to-190 ℃.
6. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein: the tempering temperature is 150-650 ℃, and the time is 1-48 h.
7. The cryogenic process for strengthening the performance of tool and die steel according to claim 1, wherein: the demagnetization treatment adopts an alternating current demagnetization method or a direct current demagnetization method, and the sample is completely demagnetized.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115198059A (en) * | 2022-06-09 | 2022-10-18 | 太原理工大学 | Magnetic field cryogenic treatment method for increasing wear resistance of 18CrNiMo7-6 carburizing steel |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN85106726A (en) * | 1985-09-04 | 1987-03-25 | 河北工学院 | The moderate magnetic field intensity magnetic field thermal treatment process of steel |
| CN102230062A (en) * | 2011-06-10 | 2011-11-02 | 西南交通大学 | Heat treatment process for improving strength and toughness of 9SiCr die steel |
| CN102296167A (en) * | 2011-08-11 | 2011-12-28 | 南车眉山车辆有限公司 | Cryogenic treatment process for 9SiCr die steel used for railway freight cars |
| CN104017965A (en) * | 2014-06-24 | 2014-09-03 | 南车眉山车辆有限公司 | Treatment process for improving toughness of Cr12MoV steel |
| CN105986091A (en) * | 2015-01-30 | 2016-10-05 | 重庆金亚模具制造有限公司 | Heat treatment technology of 9SiCr steel |
| CN106755784A (en) * | 2015-11-20 | 2017-05-31 | 巴南区伟鹏机械加工厂 | A kind of 9SiCr moulds steel heat treatment process |
| WO2018103079A1 (en) * | 2016-12-09 | 2018-06-14 | 机械科学研究总院青岛分院有限公司 | Heat treatment process for increasing resilience of bearing steel |
| CN111593179A (en) * | 2020-06-03 | 2020-08-28 | 江苏联峰实业有限公司 | Heating method of bearing steel continuous casting billet |
-
2020
- 2020-09-27 CN CN202011033407.6A patent/CN112195326A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85106726A (en) * | 1985-09-04 | 1987-03-25 | 河北工学院 | The moderate magnetic field intensity magnetic field thermal treatment process of steel |
| CN102230062A (en) * | 2011-06-10 | 2011-11-02 | 西南交通大学 | Heat treatment process for improving strength and toughness of 9SiCr die steel |
| CN102296167A (en) * | 2011-08-11 | 2011-12-28 | 南车眉山车辆有限公司 | Cryogenic treatment process for 9SiCr die steel used for railway freight cars |
| CN104017965A (en) * | 2014-06-24 | 2014-09-03 | 南车眉山车辆有限公司 | Treatment process for improving toughness of Cr12MoV steel |
| CN105986091A (en) * | 2015-01-30 | 2016-10-05 | 重庆金亚模具制造有限公司 | Heat treatment technology of 9SiCr steel |
| CN106755784A (en) * | 2015-11-20 | 2017-05-31 | 巴南区伟鹏机械加工厂 | A kind of 9SiCr moulds steel heat treatment process |
| WO2018103079A1 (en) * | 2016-12-09 | 2018-06-14 | 机械科学研究总院青岛分院有限公司 | Heat treatment process for increasing resilience of bearing steel |
| CN111593179A (en) * | 2020-06-03 | 2020-08-28 | 江苏联峰实业有限公司 | Heating method of bearing steel continuous casting billet |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115198059A (en) * | 2022-06-09 | 2022-10-18 | 太原理工大学 | Magnetic field cryogenic treatment method for increasing wear resistance of 18CrNiMo7-6 carburizing steel |
| CN115198059B (en) * | 2022-06-09 | 2023-09-08 | 太原理工大学 | Magnetic field cryogenic treatment method for increasing wear resistance of 18CrNiMo7-6 carburizing steel |
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