H13 can be tempered up to a few times, and the more times H13 mold is tempered by heat treatment, th

H13 effective thickness 170mm1040 oil quenching, first 560, 590, 600, hardness 45HRC. 2nd 560, 600, 590, hardness 48hrc. The tempering time is 6 hours per section.

The material, operation, etc. are all the same. It should be isothermal quenching.

bar. H13 is quenched with 1030, quenched at 250-300 degrees isotherm, tempered twice at 580-600 degrees, compared with the conventional quenching and tempering process, the high-temperature impact toughness is increased by 33 under the condition that the strength and plasticity of high temperature are not reduced. From the microstructure, H13 steel is quenched at 250-300 degrees isothermally, and when the quenching is cooled below MS340 degrees, it begins to form about 30 -40 martensite.

The austenite grains are segmented for the first time, and the martensite formed first has a promoting effect on the subsequent formation of the lower bainite, so the austenite equivalent grains are segmented for the second time and are more refined, and the result is that the lower bainite is refined. Due to the increase of complex interfaces, the initiation of cracks continues, and grain boundaries are added.

It has an obstructive effect on the crack, so that the crack deflects when it passes through the interface of the M phase under B. The tortuous path of crack propagation increases the energy consumption of crack propagation and fracture process, which has an improvement effect on toughness.

No, the tempering process is a process in which the quenched tissue (non-equilibrium tissue) is gradually transformed into a balanced tissue under the activation of thermal energy; It is a diffuse solid-state phase transformation process; H13 is a typical hot die steel, and the tempering temperature is in the range of 500-550 degrees Celsius; The resulting tempered tissue is tempered sostenite; As long as the tissue is evenly (s-back) obtained, the performance is guaranteed. There is no need to temper multiple times.

H13 die steel is used to manufacture forging dies with large impact loads, hot extrusion dies, and precision forging dies; Aluminum, copper and its alloys die-casting molds.

It is the H13 air quenching hardening hot work die steel introduced from the United States. Its properties and uses are basically the same as those of 4Cr5MOSIV steel, but because of its higher vanadium content, the performance of medium temperature (600 degrees) is better than that of 4Cr5MOSIV steel, and it is a representative steel grade with a wide range of uses in hot work die steel.

H13 heat treatment process.

1.Pre-heat treatment.

The best H13 steel and die blank on the market have been annealed in the steel mill to ensure that they have good metallographic structure, appropriate hardness, good processability, and no need for annealing. However, after the reforging of the manufactory, the original structure and properties were destroyed, and the forging stress was increased, and it had to be re-annealed.

The isothermal spheroidization annealing process is: 860 890 heating and holding for 2h, cooling to 740 760 isothermal 4h, and the furnace cooling to about 500 is baked.

2.Quenching and tempering.

The quenching process specification of the mold with good toughness is required: heating temperature 1020 1050, oil cooling or air cooling, hardness 54 58HRC; It requires a hot hardness based mold quenching process specification, heating temperature 1050 1080, oil cooling, hardness 56 58HRC.

Tempering should be carried out twice. At 500 tempering, there is a tempering secondary hardening peak, and the tempering hardness is the highest, with a peak of about 55HRC, but the toughness is the worst. Therefore, the tempering process should avoid about 500.

According to the needs of the use of the mold, it is better to temper in the range of 540 620.

Quenching heating should be preheated twice (600 650, 800 850) to reduce the thermal stress generated by the heating process.

3.Chemical heat treatment.

If H13 steel is gas nitrided or nitrocarburized, the mold can be further strengthened, but its nitriding temperature should not be higher than the tempering temperature to ensure that the core strength is not reduced, so as to improve the service life of the mold.

Three times. Tea has a common feature that no matter what kind of tea, its first brewing and leaching amount can account for more than 50% of the total amount of solubles, and the second brewing of ordinary tea is generally about 30%, the third time is about 10%, and the fourth time is only 1-3%. Therefore, although the number of good tea brewing is small, it is mainly because the tea leaves are tender, so they are fresh and taste good!

In addition, from a nutritional point of view, 80% of the vitamin C and amino acids in tea are leached after the first brew, and more than 95% are leached after the second brew. Other active ingredients such as tea polyphenols and caffeine are also the largest in the first extraction, and after three brewings, the full amount is basically leached.

1. The first soup of tea (the first tea soup "water") cannot be poured, because the soluble organic components in the tea are about 80% of the tea brewed for the first time, about 10% of the second soup, and 5% of the third soup. So what do you do with tea after the first soup is poured? It's worthless to soak it naturally three times.

2. The more tender the tea is relatively good (except for oolong), and the good tea generally has only one or two soups.

3. After the tea is soaked for a long time, the heavy metals and other toxic substances in it will come out.

H13 belongs to alloy tool steel, because the steel contains a large number of alloying elements, the hardenability of the steel is very good, often after quenching will retain a large number of residual austenite, these residues will only continue to be transformed into martensite in the process of tempering and cooling, that is, the so-called "secondary quenching". After the first tempering, due to the formation of new martensite will produce new internal stresses, and there may still be some untransformed Paralympics, it is necessary to carry out secondary tempering or even tertiary tempering. The tempering temperature is generally 550 600, and the tempering time depends on the amount of furnace and the effective wall thickness of the parts.

H13 steel and its heat treatment.

Material H13, annealed.

H13 steel and its heat treatment.

1.Spheroidization annealing after forging The steel should be annealed in time after forging. The annealing temperature is 860 880 oC.

It can reduce the hardness of the material, improve the machinability, and prepare the structure for the later quenching treatment. The annealing and holding time depends on the burn-through time of the workpiece, and should not be too long. The cooling rate is less than 3o h, and the cooling is less than 500 oC.

2.Stress relief retreats.

It is best to find the parameter table of heat treatment for material properties. Quenching: 790 degrees +-15 degrees preheating, 1000 degrees (salt bath) or 1010 degrees (furnace control atmosphere) +-6 degrees heating, heat preservation 5 15min air cooling, 550 degrees +-6 degrees tempering; Annealing, hot working.

52hrc！Some H13 heat treatment will not reach such a high level, because they are all from small factories!

The best quenching and tempering process for H13 die steel is: 1020 1080 oil cold quenching or grading quenching after heating, followed by 560 600 two tempering.

The microstructure is tempered tropenite + tempered sostenite + residual carbide, and the microhardness is 48 52HRC.

For die-casting molds that require high hot hardness, the upper heating temperature can be quenched. For dies (hot forging dies) that require toughness, the lower limit heating temperature can be removed and quenched.

The purpose of the spheroidization annealing process is to homogenize the structure, reduce the hardness, improve the machining performance, and prepare the structure for quenching and tempering. The spheroidization annealing process is held at 845 900 (1h+1min) mm, then the furnace is cooled to 720 740 isothermal (2h+1min) mm, and finally the furnace is cooled to 500 air cooling, and the spheroidized annealing structure is granular pearlite, and the hardness is less than 229hbs.

According to the conventional use of H13, the common quenching tempering hardness HRC47-49 is recommended.

The grade determines the carbon content, and the carbon content determines the highest hardness of quenching and tempering, and then selects the appropriate heat treatment process and hardness according to the use purpose.

CICC mould steel.

H13 is a hot work die steel, which is a steel grade formed by adding alloying elements on the basis of carbon steel, and the standard GB T1299-2014 is implemented. Unified numerical code T23353; Grade: 4CR5MOSIV1. It has good comprehensive performance at medium temperature (600°), high hardenability (it can be hardened in air), low deformation rate of heat treatment, and its performance and service life are higher than 3Cr2W8V.

It can be used for die forging hammer forging die, aluminum alloy die-casting mold, hot extrusion die, high-speed precision forging die and forging press mold, etc.

Mechanical properties. Hardness: annealed, 245 205HB, quenched, 50HRC

Delivery status. Brinell hardness HBW10 3000 (229)).

Key features: H13 steel is the most widely used and representative hot work die steel grade, and its main characteristics are:

1) It has high hardenability and high toughness;

2) Excellent thermal cracking resistance, can be water-cooled in the workplace;

3) It has medium wear resistance, and carburizing or nitriding processes can also be used to improve its surface hardness, but the thermal cracking resistance should be slightly reduced;

4) Because of its low carbon content, the secondary hardening ability in tempering is poor;

5) It has the ability to resist softening at higher temperatures, but the hardness decreases rapidly when the operating temperature is higher than 540 (1000) (i.e., the operating temperature is 540);

6) The deformation of heat treatment is small;

7) Medium and high machinability;

8) Medium resistance to decarburization.

Even more notably, it can also be used to make important components in the aviation industry.

Everyday use. The use is basically the same as that of 9CrWMN die steel, but because of its higher vanadium content, the performance of medium temperature (600 degrees) is better than that of 4Cr5MOSIV steel, which is a representative steel grade with a wide range of uses in hot work die steel.

H13 die steel is used to manufacture forging dies with large impact loads, hot extrusion dies, and precision forging dies; Aluminum, copper and its alloys die-casting molds.

1.Quenching specification: temperature 1020--1050 degrees, cooling medium: oil or air, hardness HRC: 56--58

2.Tempering specification: temperature 560--580 degrees, cooling: air cooling, tempering hardness HRC: 47--49

3.Usually two tempering is used, and the temperature of the second tempering should be 20 degrees lower than the first.

H13 die steel, forging die, hot extrusion die, precision forging die, aluminum products, copper and its alloys, die-casting mold, round steel, special-shaped steel, control hardness 50 is the best.

600 640 can, we 41 48 use this temperature tempering.

Why is the heat treatment of H13 mold serious?