CN104313257A - Modified tempering furnace and tempering method - Google Patents
Modified tempering furnace and tempering method Download PDFInfo
- Publication number
- CN104313257A CN104313257A CN201410603435.5A CN201410603435A CN104313257A CN 104313257 A CN104313257 A CN 104313257A CN 201410603435 A CN201410603435 A CN 201410603435A CN 104313257 A CN104313257 A CN 104313257A
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- Prior art keywords
- tempering
- stove
- workpiece
- inert gas
- nitrogen
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Classifications
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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
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
-
- 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
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
- C21D1/773—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material under reduced pressure or vacuum
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a tempering method. The tempering method comprises the following steps: additionally mounting a vacuum extractor and an inert gas charging device on a common tempering furnace, and tempering and cooling a workpiece under a protective atmosphere, so as to prevent that the workpiece is oxidized by the oxygen in the air at high temperature, further obviously prolong the service life of the workpiece, and lower the production cost.
Description
Technical field
The present invention is specifically related to a kind of tempering stove and tempering method of improvement, for promoting the life-span of die casting, plastic mould.
Background technology
Tempering is that workpiece is hardened post-heating to Ac
1following a certain temperature, held for some time, the then thermal treatment process of cool to room temperature.Tempering can make the use properties needed for workpiece acquisition.
Steel is general little direct use after quenching, because the tissue after quenching is martensite and residual austenite, and have internal stress to produce, although martensite intensity, hardness are high, plasticity is poor, and fragility is large, under internal stress effect, easily produce distortion and cracking; In addition, after quenching, tissue is unstable, at room temperature just can slowly decompose, and produces volume change and causes workpiece deformation.Therefore, the part after quenching must carry out tempering and could use.
The object of tempering is: the residual stress produced when eliminating workpiece quenching, prevents distortion and cracking; Adjust the hardness of workpiece, intensity, plasticity and toughness, reach use properties requirement; Stabilizing tissue and size, ensure precision; Improve processing characteristics.Therefore, tempering is last one important procedure that workpiece obtains desired properties.
By tempering range, tempering can be divided into low-temperaturetempering, average tempering and high tempering.
The structural transformation of hardened steel can be divided into four-stage: martensitic decomposition (less than 200 DEG C) → residual austenite decomposes formation (250 ~ 400 DEG C) → cementite agglomeration (more than 400 DEG C) of (200 ~ 300 DEG C) → cementite.Along with tempering temperature raises, quenching internal stress constantly declines or eliminates, and hardness declines gradually, and plasticity, toughness raise gradually.
Die casting, plastic mould cause early failure due to thermal treatment process, are mainly manifested in: early stage check surface or sticking to mould and polishing performance poor.
The defect of the reason of above-mentioned early failure mainly early stage tempering equipment itself is caused to cause.These equipment workpiece when tempering is all in air, simultaneously because die casting or plastic mould mostly comparatively are big-and-middle, therefore repeatedly tempering is needed, and tempering time is long, the mould of such condition of high temperature is very easily by the dioxygen oxidation in air, form darker zone of oxidation at die surface, serious even can produce decortication phenomenon, and the grain structure of die surface is subject to major injury.Although have precision work follow-up to repair, these damage to organize and still may extend to deep tissues.And the use of the high temperature in later stage and other complex environment can aggravate its failure effect.
In order to solve the problem of mould early failure, the method for employing or the development of tempering equipment are divided into three phases.
First stage, adopt chamber type electric resistance furnace and the pit furnace not with atmosphere protection.Tempering can cause mould to be oxidized in atmosphere, and along with the prolongation of tempering time or the rising degree of oxidation of tempering temperature more serious.
Subordinate phase, adopting the pit furnace by dripping olein or kerosene formation atmosphere protection, partly can solve problem of oxidation, reach anti-oxidation effect, but effect being unsatisfactory.Major cause is: the material of dropping can decompose generation hydrogen and environmentally harmful material at high operating temperatures, and hydrogen and mould generation chemical reaction, make mould generating portion Hydrogen Brittleness Phenomena, affect early failure.
Phase III, adopt vacuum tempering equipment.Vacuum tempering can effectively avoid die surface problem of oxidation, but vacuum tightness is high to equipment requirements, selling at exorbitant prices, and what exceed general enterprises can tolerance range, and is not suitable for the mould tempering of short run.Meanwhile, owing to being vacuum state during workpiece tempering, mould only have radiation a kind of by hot mode, in stove, the different positions temperature difference is large, comparatively large for the impact of big-and-middle, causes tempering uneven.
Therefore, need to improve tempering equipment and tempering method.
Prior art:
When utilizing tempering stove of the prior art to carry out temper to workpiece, its process is as follows:
First, the temperature of tempering stove rises to 200 DEG C from room temperature in 30min,
Secondly, when furnace temperature rises to 200 DEG C, then start recirculation blower intensification tempering, be warming up to 700 DEG C, and constant temperature 6 hours.
Finally, when being cooled to 400 DEG C after tempering terminates, workpiece is come out of the stove air cooling.
Metallographic mensuration is carried out to workpiece, the results are shown in Figure 2.
The contrast of prior art and embodiment 1:
As Fig. 2, when workpiece after tempering, carries out metallographic detection in common air tempering stove, choose three points and measure, the thickness of zone of oxidation is followed successively by 26.54,24.41,25.12 μm, and mean value is 25.36 μm.
As Fig. 3, when workpiece is in the nitrogen protection tempering stove improved after tempering, then metallographic detection is carried out to it, contrast with Fig. 2 the thickness not measuring zone of oxidation in known Fig. 3, namely there is no zone of oxidation.
The contrast of Fig. 3 and Fig. 2, obviously can disclose the superiority of the structure that workpiece processes in nitrogen protection tempering stove.
Summary of the invention
For solving the problems of the technologies described above, the present invention proposes a kind of tempering stove and tempering method of improvement, making the oxygen-barrier of workpiece when tempering and in air, not producing zone of oxidation, thus reach the object improving the workpiece life-span.
For achieving the above object, technical scheme of the present invention is as follows:
A tempering stove for improvement, comprises tempering stove, and described tempering stove installs a set of vaccum-pumping equipment and a set of inert gas plenum equipment additional, described inert gas plenum equipment comprises rare gas element compression bottle, reducing valve, safety valve and inflation valve; Described safety valve, reducing valve and inflation valve are located on the air outlet pipeline of rare gas element compression bottle in turn.
Preferably, the gas in described rare gas element compression bottle is the one in nitrogen, helium, argon gas.
A kind of tempering method, comprises the steps:
First, before tempering intensification arrival 200 DEG C, start vaccum-pumping equipment tempering stove is vacuumized, remove air;
Secondly, when furnace temperature rises to 200 DEG C, filling with inert gas enters flue, then starts recirculation blower intensification tempering, needs in the process to ensure inert gas pressure > barometric point in stove, and keeps stable;
Finally, after tempering terminates, bleed off the rare gas element of heat, then filling with inert gas be cooled to≤400 DEG C time, workpiece is come out of the stove air cooling.
Preferably, the vacuum tightness≤1000Pa after the tempering stove in the first step vacuumizes.
The present invention's advantage is compared with prior art:
1, the tempering stove after improving first can vacuumize inflated with nitrogen (rare gas element) again, makes workpiece avoid oxidation when tempering.This mode not only cost is low, and pressure reduction inside and outside body of heater is little, and can not produce tempering stove and destroy, tempering is simultaneously effective.
2, during tempering, in stove, be filled with the nitrogen of constant pressure, transmission of heat by convection can be increased and to make in body of heater more uniform temperature everywhere stablize, be conducive to the average tempering of big-and-middle, make workpiece hardness even; Because nitrogen is rare gas element, can become protective atmosphere when tempering, available protecting workpiece is not oxidized, and nitrogen to enter after air environment without any harm, is conducive to environmental protection.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below.
Fig. 1 is the structural representation of the tempering stove of a kind of improvement disclosed in the embodiment of the present invention 1;
Fig. 2 is the metallograph (magnification: 400) of workpiece after the process of normal atmospheric tempering stove;
Fig. 3 is the metallograph (magnification: 400) after workpiece processes in nitrogen protection tempering stove.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described.
Embodiment 1.
As Fig. 1, a kind of tempering stove of improvement, comprises common tempering stove 1 (during tempering, inside is air), the body of heater of tempering stove 1 installs additional a set of vaccum-pumping equipment (vacuum pump) 2 and a set of inert gas plenum equipment.
Inert gas plenum equipment comprises rare gas element compression bottle 3, and is located at safety valve 4, reducing valve 5 and the inflation valve 6 on its air outlet pipeline in turn.
Gas in rare gas element compression bottle is the one in nitrogen, helium, argon gas.
Cheap High Purity Nitrogen is selected in this example.
Utilize the tempering equipment after improving to carry out work, tempering method is as follows:
First, the temperature of tempering stove rises to 200 DEG C from room temperature in 30min, and in the process, start vaccum-pumping equipment (vacuum pump) and vacuumize tempering stove, remove air, vacuum tightness is evacuated to 800pa (vacuum tightness≤1000Pa).
Secondly, when furnace temperature rises to 200 DEG C, fill High Purity Nitrogen and enter flue, then start recirculation blower intensification tempering, need in the process to ensure nitrogen pressure in furnace > barometric point, and keep stable; Method can increase by a tracheae at the nitrogen outlet place of body of heater, and tracheae stretches into below the water surface, and the speed that observation bubble is emerged judges.Only need bubble at the uniform velocity to emerge, illustrate that inside is malleation.Continue to be warming up to 700 DEG C, and constant temperature 6 hours.
Finally, bleed off the nitrogen of heat after tempering terminates, then when inflated with nitrogen is cooled to 400 DEG C, workpiece is come out of the stove air cooling, and surface is lividity.
Metallographic mensuration is carried out to workpiece, the results are shown in Figure 3.
Embodiment 2.
Utilize the tempering equipment after the improvement in embodiment 1 to carry out work, tempering method is as follows:
First, the temperature of tempering stove rises to 200 DEG C from room temperature in 30min, and in the process, start vaccum-pumping equipment (vacuum pump) and vacuumize tempering stove, remove air, vacuum tightness is evacuated to 600pa.
Secondly, when furnace temperature rises to 200 DEG C, fill High Purity Nitrogen and enter flue, then start recirculation blower intensification tempering, need in the process to ensure nitrogen pressure in furnace > barometric point, and keep stable; Method can increase by a tracheae at the nitrogen outlet place of body of heater, and tracheae stretches into below the water surface, and the speed that observation bubble is emerged judges.Only need bubble at the uniform velocity to emerge, illustrate that inside is malleation.Continue to be warming up to 650 DEG C, and constant temperature 8 hours.
Finally, bleed off the nitrogen of heat after tempering terminates, then when inflated with nitrogen is cooled to 330 DEG C, workpiece is come out of the stove air cooling, and surface is lividity.
Embodiment 3.
Utilize the tempering equipment after the improvement in embodiment 1 to carry out work, tempering method is as follows:
First, the temperature of tempering stove rises to 200 DEG C from room temperature in 30min, and in the process, start vaccum-pumping equipment (vacuum pump) and vacuumize tempering stove, remove air, vacuum tightness is evacuated to 800pa.
Secondly, when furnace temperature rises to 200 DEG C, fill High Purity Nitrogen and enter flue, then start recirculation blower intensification tempering, need in the process to ensure nitrogen pressure in furnace > barometric point, and keep stable; Method can increase by a tracheae at the nitrogen outlet place of body of heater, and tracheae stretches into below the water surface, and the speed that observation bubble is emerged judges.Only need bubble at the uniform velocity to emerge, illustrate that inside is malleation.Continue to be warming up to 620 DEG C, and constant temperature 7 hours.
Finally, bleed off the nitrogen of heat after tempering terminates, then when inflated with nitrogen is cooled to 200 DEG C, workpiece is come out of the stove air cooling, and surface is yellowish white.
The present invention's advantage is compared with prior art:
1, the tempering stove after improving first can vacuumize inflated with nitrogen (rare gas element) again, makes workpiece avoid oxidation when tempering.This mode not only cost is low, and pressure reduction inside and outside body of heater is little, and can not produce tempering stove and destroy, tempering is simultaneously effective.
2, during tempering, in stove, be filled with the nitrogen of constant pressure, transmission of heat by convection can be increased and to make in body of heater more uniform temperature everywhere stablize, be conducive to the average tempering of big-and-middle, make workpiece hardness even; Because nitrogen is rare gas element, can become protective atmosphere when tempering, available protecting workpiece is not oxidized, and nitrogen to enter after air environment without any harm, is conducive to environmental protection.
To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the present invention.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein can without departing from the spirit or scope of the present invention, realize in other embodiments.Therefore, the present invention can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (4)
1. the tempering stove improved, comprise tempering stove, it is characterized in that, described tempering stove installs a set of vaccum-pumping equipment and a set of inert gas plenum equipment additional, described inert gas plenum equipment comprises rare gas element compression bottle, reducing valve, safety valve and inflation valve; Described safety valve, reducing valve and inflation valve are located on the air outlet pipeline of rare gas element compression bottle in turn.
2. the tempering stove of a kind of improvement according to claim 1, is characterized in that, the gas in described rare gas element compression bottle is the one in nitrogen, helium, argon gas.
3. a tempering method, is characterized in that, comprises the steps:
First, before tempering intensification arrival 200 DEG C, start vaccum-pumping equipment tempering stove is vacuumized, remove air;
Secondly, when furnace temperature rises to 200 DEG C, filling with inert gas enters flue, then starts recirculation blower intensification tempering, needs in the process to ensure inert gas pressure > barometric point in stove, and keeps stable;
Finally, after tempering terminates, bleed off the rare gas element of heat, then filling with inert gas be cooled to≤400 DEG C time, workpiece is come out of the stove air cooling.
4. a kind of tempering method according to claim 2, is characterized in that, the vacuum tightness≤1000Pa after the tempering stove in the first step vacuumizes.
Priority Applications (1)
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| CN201410603435.5A CN104313257A (en) | 2014-10-31 | 2014-10-31 | Modified tempering furnace and tempering method |
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| CN201410603435.5A CN104313257A (en) | 2014-10-31 | 2014-10-31 | Modified tempering furnace and tempering method |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107649577A (en) * | 2017-09-19 | 2018-02-02 | 湖州科创机械有限公司 | A kind of damping disk(-isc) perforating die die process |
| CN107671501A (en) * | 2017-09-28 | 2018-02-09 | 山东交通职业学院 | A kind of production technology of planet carrier |
| CN108187406A (en) * | 2017-12-18 | 2018-06-22 | 厦门市浩铂科技股份有限公司 | A kind of composite filter element and its production method |
| CN110438440A (en) * | 2019-08-30 | 2019-11-12 | 日照职业技术学院 | A kind of glow discharge nitriding duplex surface modification processing method |
| CN114014566A (en) * | 2021-11-29 | 2022-02-08 | 盐城工业职业技术学院 | Method for preparing regenerated cementing material by using waste concrete |
| CN114134305A (en) * | 2021-11-16 | 2022-03-04 | 张雯皓 | Tempering furnace for heat treatment process |
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| CN102560037A (en) * | 2011-12-30 | 2012-07-11 | 豫西工业集团有限公司 | High-strength steel thin-wall piece vacuum thermal treatment process |
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| CN102560037A (en) * | 2011-12-30 | 2012-07-11 | 豫西工业集团有限公司 | High-strength steel thin-wall piece vacuum thermal treatment process |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107649577A (en) * | 2017-09-19 | 2018-02-02 | 湖州科创机械有限公司 | A kind of damping disk(-isc) perforating die die process |
| CN107671501A (en) * | 2017-09-28 | 2018-02-09 | 山东交通职业学院 | A kind of production technology of planet carrier |
| CN108187406A (en) * | 2017-12-18 | 2018-06-22 | 厦门市浩铂科技股份有限公司 | A kind of composite filter element and its production method |
| CN110438440A (en) * | 2019-08-30 | 2019-11-12 | 日照职业技术学院 | A kind of glow discharge nitriding duplex surface modification processing method |
| CN114134305A (en) * | 2021-11-16 | 2022-03-04 | 张雯皓 | Tempering furnace for heat treatment process |
| CN114014566A (en) * | 2021-11-29 | 2022-02-08 | 盐城工业职业技术学院 | Method for preparing regenerated cementing material by using waste concrete |
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Application publication date: 20150128 |