1, H13 die steel heat treatment hardness can reach 58 ℃?

In 1050 ~ 1100 ℃ heating quenching, quenching oil, can meet the requirements, but generally hot-work die is not ask such a high hardness, high hardness performance will be very bad, bad to use, generally in HRC46 ~ 50 good performance, durable.

2, mould heat treatment after surface with what to wash white?

Problems added: I am a open mold polishing shop, general mould with oil stone played first, then take nitriding, nitriding back again with oil stone to rub it a layer of black white, polishing again very troublesome, don't mirror to wipe a game of shuttlecocks, material H13, have import good variety of, if there is one potion can wash white, can direct and polishing.

(1) can be used stainless steel pickling liquor, or hydrochloric acid cleaning. Sandblasting processing can also. Grinding machine for grinding of the high cost of words, and it was big, has the potential to size substandard. Hydrochloric acid wash not to drop, the estimate is high chromium steel you use? D2 or H13? High chromium oxide layer of steel difficult to wash out. Stainless steel pickling liquor should be ok, grinding tool shops or stores are sold of stainless steel.

(2) you don't have stainless steel pickling paste? That kind of can. H13 such higher chromium steel, oxidation layer is hard to wash with hydrochloric acid. There is a way to, I also in use. Since your mould has been oil stone mill, the surface is relatively smooth. In fact, you can only use first crude oil stone grinding, or with sand belt grinding, after heat treatment. Back then with fine abrasive polishing. And I is to use fiber wheel grinding, can effectively remove black, grinding and polishing. Purpose or sand, with 800 boron carbide do sandblasting try again, should be able to remove black, don't need too many kungfu resharpening.

3, heat treatment of metal is how heat treatment?

Heat treatment equipment is very much, about the stove chamber furnace, pit type furnace, box-type furnace use most, a lot of heat treatment can be in this process, such as annealing, normalizing and quenching heating process, tempering these common heat treatment.

Is actually a electricity heating stove, the stove heating up to the predetermined temperature first, then throw the artifacts, wait for a period of time to the predetermined temperature, then heat preservation for a period of time, then remove them, or in the oven with cooling, pit type furnace is as a general carburizing processing equipment, is a stove, buried to the ground after the workpiece in, seal, and then to the stove drip inside some carbon-rich liquid, such as kerosene or methanol, and then down into the liquid at high temperature carbon atoms into the workpiece surface.

Is the place that quenching, quenching pool is a pool, there is a solution, or oil, box-type furnace is out of quench cooling, general is directly, and then wait for a period of time out. And other equipment, such as high frequency machine, is a can be 50 hz power frequency electric to become a super power of 200 k hz current devices, such as common has the maximum power of 200 kilowatts, and then made of a copper pipe internal cooling water flux coil on the outside of the artifacts, typically a few millimeters artifacts, a few seconds to 10 seconds when you see the red on the surface of the work, the surface temperature to the desired value, and has set up a water spray quenching liquid to the surface, to complete the quenching process. These are all common.

4, our recent Cr12 or Cr12MoV material heat treatment and the cracked a few times, why?

Hardware mold will best parts size, shape, and heat treatment requirements, and tell you to take the heat treatment process of curve, otherwise it's hard to tell. These two kinds of steel is a kind of, is a high carbon high chromium ledeburite steel, itself has a tendency to cold cracking. Heat treatment process is more complicated.

Below in the absence of the above information is talk about my experience: 950-1000 - c, quenching oil cooling, HRC > 58. In order to obtain the red hardness and high wear resistance, quenching temperature increased to 1115-1130 - c, oil cooling. Thin air cooling, in order to reduce the deformation in the 400-450 - c also salt liquid cooling. Don't in the 300-375 - c tempering, can reduce the toughness of the tool, appear the temper brittleness, and immediately after quenching tempering. Higher than 1100 c quenching, c tempering 2-3 times in 520. Please note that the high quenching temperature will tend to decarburization, therefore can be in advance before quenching, spheroidizing annealing heat treatment.

5, how to distinguish between heat treatment and artifacts without heat treatment?

Problems added: workers accidentally put a born without heat treatment and a batch of debugging good after heat treatment of workpiece, how to distinguish them now, don't look metallographic cutting workpiece, that will damage the product, to rush delivery? Heat treatment process of 30 cr after normalizing and quenching and tempering, is casting without heat treatment. Both through the blasting processing yan color change not to come out, and the hardness is between 35 and 45, rely on hardness are indistinguishable. If can't discriminant by hardness and heat treatment of oxidation color. I suggest that you identify by percussion. The casting and quenching + tempering workpiece microstructure is different, there are differences between the internal friction, by tapping, might be able to distinguish.

6, burnt in the heat treatment is what mean?

In excess of the prescribed heating temperature, the grain growth, the mechanical properties of bad such as brittleness, toughness, easy to deformation and cracking and so on, control the heating temperature can avoid burnt. To the solid steel liquidus temperature range when heated to above a certain temperature, chemical composition changes have taken place in the austenitic grain boundary, partial or whole grain boundaries appear burning-out phenomenon. At grain boundary on the enrichment of S and P and other compounds, results in the decrease of grain boundary binding force, mechanical performance deteriorated badly. After burning steel cannot be remedied by heat treatment or processing methods.

7, die quenching crack reasons and preventive measures?

The reason:

1) mould materials exist serious meshy carbide segregation.

2) existing in the mould machining or cold plastic deformation stress.

3) mould improper heat treatment operation (heating or cooling too quickly, improper selection, cooling quenching cooling medium low temperature, cooling time is too long, etc.).

4) die complex shape, thickness, Angle and threaded hole, etc., make the thermal stress and organization stress is too large.

5) die quenching heating temperature is too high to produce excessive heat or burn.

6) the mold after quenching tempering time insufficient tempering heat preservation time.

7) quenching heating mould repair, without intermediate annealing and quenching again.

8) mould heat treatment, improper grinding technology.

9) mold edm after heat treatment, have higher tensile stress exist in the hardening layer and micro crack.

Preventive measures:

1) strictly control mold the immanent quality of raw materials

2) improve the forging and spheroidizing annealing process, eliminate the mesh, belt, chain carbide, improve spheroidizing together all of the organization.

3) or after cold plastic deformation after machining of mould should be to stress annealing (> 600 ℃) after quenching.

4) to the complex shape of mould should use asbestos jams threaded hole, bandaging and thin wall, the dangerous section and using level of quenching and isothermal quenching.

5) is required for a repair or refurbish mould for annealing or high temperature tempering.

6) mould preheating, should be taken in quenching heating cooling precooling measures, and select suitable quenching medium.

7) should strictly control the quenching heating temperature and time, to prevent overheating and burnt mould.

8) mould should be timely after quenching tempering, heat preservation time to fully, high alloy complex mould should temper 2-3 times.

9) to select the correct grinding process and the appropriate grinding wheel.

10) improve mold edm process, and to stress tempering.

8, how large stamping die heat treatment? Especially trimming this kind of mold production often have burr, cannot run normally.

(1) the mold heat treatment as far as possible choose vacuum heat treatment, in order to obtain the minimum deformation.

(2) the mold can be used splicing structure, good heat treatment is divided into small pieces. It is better to slow wire cut, high precision, high brightness, small deformation. Guaranteed clearance, burr will be smaller. See if your device accuracy is poor.

(3) cutting burr in addition to several of the above mentioned, I think the punch force, unilateral insufficient strength may be great. Whether the punch is too thin? Whether to design a knife? And residual stresses after heat treatment of metal deformation will be shown after the line cut, can consider a larger milling and heat treatment on line cutting holes in advance, for 3 ~ 4 mm wire cut.

9, I use H13 steel for hot extrusion die forging workpiece is brass heat treatment of 45 ~ 48 ° die diameter of 120 mm, 70 mm high, die cracking after working hours?

(1) forging temperature is about 900 ~ 1000 ℃? Temperature is too high? Die without fully preheated before use may also be easy to crack. Mold design unreasonable may also be easy to crack. Increases the tempering temperature of the mold, to narrow the gap and the actual forging temperature, tempering the actual longer.

(2) this to consider, when necessary to do metallographic, basic judgment reason to oh.

10, mold surface is soft point causes and prevention?

The reason:

1) the mold surface of oxide skin before heat treatment, rusty spot and partial decarburization.

2) mold after quenching heating, incorrect cooling quenching medium, quenching medium impurities too much or aging.

Preventive measures:

1) mould should be removed before heat treatment scale, rusty spot, appropriate protection mould surface quenching heating, should try to adopt the vacuum furnace, salt bath furnace with protective atmosphere heating furnace.

2) die quenching cooling after heating, should choose the appropriate cooling medium, the cooling medium to the long-term use by filtering, or replaced periodically.

Poor organization before 11, mould heat treatment?

The reason:

1) the steel raw material have serious carbide segregation.

2) poor forging process, such as forging heating temperature is too high, small deformation, slow stop forging temperature is high, the cooling speed after forging, etc., make forging organization bulky and mesh, belt and chain carbide exists, the spheroidizing annealing is difficult to eliminate.

3) poor spheroidizing annealing process, such as the annealing temperature is too high or too low, the isothermal annealing time is short, etc., can result in uneven spheroidizing annealing organization or bad nodulizing.

Preventive measures:

1) should be based on general mold working conditions, the production batch and material itself strong performance, try to choose the steel material with good quality.

2) improve the forging process or use prepare normalizing heat treatment, to eliminate the raw materials of mesh and chains inhomogeneity of carbide and carbon compound.

3) to forging of carbide segregation serious not high carbon steel refine solid solution heat treatment can be performed.

4) after forging die blanks, formulate correct spheroidizing annealing process specification, tempering heat treatment can be used well and rapid spheroidizing annealing.

5) reasonable furnace charging, to guarantee the uniformity of mold temperature of billet inside the furnace.

After 12, die quenching organization bulky, will make the mold produces fracture when using, the serious influence the service life of mould?

Reasons:

1) mould steel confusion, actual steel quenching temperature of quenching temperature is far lower than the request mould material (such as the use of GCr15 steel as 3 cr2w8v steel).

2) had not been properly before quenching steel spheroidizing process, spheroidizing bad organization.

3) die quenching heating temperature or holding time is too long.

4) mold is placed in a furnace, improper, near the electrode or heating element area are prone to overheating.

5) to changes in cross section larger mould, improper quenching heating craft parameter selection, overheating in thin section and sharp corners.

Preventive measures:

1) steel storage should be strictly tested before, protected from steel to confuse the place.

2) should be done before die quenching correct forging and spheroidizing annealing, in order to ensure good spheroidizing organization.

3) correct make die quenching heating process specification, strictly control the quenching heating temperature and holding time.

4) detection and correction thermometer table on a regular basis, guarantee the normal work of the instrument.

5) mold in furnace heating should keep proper distance with electrodes or heating element.

13, made cold mould Cr12MoV steels should be how to carry out heat treatment?

High hardness, high wear resistance and high toughness optimization: 980 ~ 1200 ℃ heating quenching, quenching oil (oil) 400 ℃ tempering time, 240 ℃ tempering time, HRC57 ~ 61, super durable blade won't crack.

14, H13 die steel heat treatment after the crack is what reason, quenching temperature is 1100 ℃, and in the oil cooling?

Metallographic analysis can be done, see if there is a material surface decarburization phenomenon, commonly if cracking is caused decarburization, H13 is usually do extrusion die, hardness of the material request is not high, do you use vacuum furnace proposal in 1030 ~ 1050 ℃.

15, mould of guide pin guide bush usually adopt what material? What heat treatment, the performance requirements of reach?

(1) in the mainland with 45 # carbon constructional steel or carbon tool steel, heat treatment quenching hardness HRC45, short of HRC58-62, is so high, very easy to break.

(2) high demand is a board with SKD61 or SKD11 and H13 about heat treatment such as quenching HRC51 hardness.

16. The use of heat treatment in mould manufacturing? How to apply?

Question supplement: is the template processing after heat treatment, which is the main link?

Heat treatment role in mould manufacturing, improve the hardness, wear resistance, so as to improve their life; Strengthen the intensity, deformation is reduced, to guarantee the precision and accuracy stability of the mould.

17, mould analysis the reason of failure?

Failure is mostly caused by fracture, wear and deformation, the main reason is improper heat treatment and mould processing. Therefore, the reasonable material selection, formulate correct heat treatment process, improve the quality of heat treatment, plays a vital role for extending the service life of the mold. Mold heat treatment including preliminary heat treatment and final heat treatment, heat treatment of the final purpose is to make the mold with good surface quality and strength, plasticity and toughness of the reasonable.

18, Cr12mov die steel after heat treatment piece by piece off?

(1) you may be in quenching, over temperature too much, overheating, cause coarse grains, decarburization, martensite is bulky, fracture surface coarse grain, toughness and low plasticity. (2) high heating temperature, holding time is too long, cause material surface decarbonization serious, organization coarse grains, poor adhesion strength, plasticity significantly reduced. Suggestion: proofreading heating equipment; Adjust the quenching, tempering temperature and time; Do the heat treatment process tests, the necessary performance test and analysis.

The advantages of 19, salt bath heat treatment?

Advantages: heated evenly deformation is small, no oxidation decarburization, less heat fast, can quickly change the workpiece internal group woven structure, heat preservation performance and heating performance is good, can undertake heating solid solution treatment, applicability widely, almost no oxidation can be delivery processing, etc. Weakness: the poor working conditions, the workpiece has certain corrosion, service life is relatively short, working space size and power, power is larger, the size is smaller. And FeiYan some pollution to the environment, if customers have higher request for no oxidation to consider, the cost in general.

20 and test effect of heat treatment with what method?

A simple check surface hardness. Accurate break check: check the depth of hardening layer, the core hardness, quenching microstructure grade, quenched and tempered microstructure level. The depth of hardening layer hardness value = critical quenching hardness minimum X0.8.

21, mould materials cryogenic treatment effect have?

The continuation of cryogenic treatment after quenching workpiece cooling process, the application in the mold industry mainly embodied in the cold work die steel and high speed steel, bearing steel, cold work mould and mould parts have cryogenic technology application case. Cryogenic will change some mechanical properties, main functions as follows: improve workpiece hardness and strength, to guarantee the size of the workpiece precision improve the wear resistance, improve the impact toughness of artifacts, improve the internal stress distribution of workpiece, to improve the fatigue strength, improve the corrosion resistance of workpiece.

22, wire cut crack after heat treatment is a question of templates or heat treatment of the problem?

(1) I'm on the heat treatment, I personally think that is a question of heat treatment. Because there is no after heat treatment of steel wire cutting is hard to crack, wire-cutting cracking because of cutting appear stress concentration. So when the heat treatment not only to meet the requirements of heat treatment of hardness will also have to eliminate internal stress. The key to eliminate internal stress is tempering temperature and tempering time. If the tempering temperature is too bottom, tempering time long also cannot eliminate internal stress; If the tempering temperature is too high, while eliminating stress, but cannot meet the requirements; If the tempering temperature is appropriate, but the tempering time is too short, stress cannot be completely eliminated. So after the heat treatment line crack is the key to control of tempering temperature and tempering time. (2) after the heat treatment line crack this kind of situation is more complex, the possibility of mold inadequate quenching tempering after, when there are mould forging defects in May. If it is the general carbon steel mold, insufficient tempering is the main reason, needs to give priority to, for high alloy mould, may also be defective materials, such as impurity, carbide segregation, etc., these need at high magnification metallographic testing to determine.

23, Cr12MoV, the blowout reasons of heat treatment have?

(1) whether the coolant cooling too quickly (can't use salt water, water, etc.) (2) before quenching, may not return a good fire, caused by excessive internal stress (3) the bad materials metallurgy, non-metallic inclusions and banded structure, eutectic carbide) (4) quenching, furnace temperature rises too fast (5) there is no tempering in time

24, what is a heat treatment strengthening?

Surface treatment: such as hard chrome plating, increase the parts wear resistance; Shot peening, used to withstand the work under alternating stress components, can greatly improve the fatigue strength; Roller: using the rolling tool under the state of the pressure on the surface of parts, make the metal surface to produce plastic deformation, modified metal surface micro geometry shape, improving surface finish and improve fatigue strength and wear resistance and hardness of the parts.