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How to perform heat treatment on P20 steel?

If we know more about it ,we can take advantage of the p20 better. At the same time ,We can work efficiently.

heat treatment on P20 steel

The mass fraction of Mo in this steel reaches 0.46%, which can suppress the transformation of austenite to pearlite, improve the stability of austenite, and improve the hardenability and tempering resistance of steel. The simultaneous presence of Mo, Cr, and Mn can reduce or suppress the temper brittleness caused by other elements. If the mass fraction of Mo in the steel reaches 0.50%, the temper brittleness can be eliminated.

Mo has a solid solution strengthening effect on ferrite.and at the same time, it can improve the stability of carbides, improve the impact toughness and recrystallization temperature of the mold. that is, increase the creep resistance of ferrite at high temperature. It can effectively inhibit the cementite from growing up at 450 ~ 600 ℃ .It can promote the precipitation of dispersed special carbides, further strengthen the matrix, and enhance wear resistance.

what shall we pay attention to during heat treatment on p20 steel?

However, the high-temperature oxidation resistance of molybdenum (Mo) steel is poor. the protection of the die should be paid attention to during heat treatment. When Mo steel is heat-treated in a vacuum furnace, Mo will volatilize under a high vacuum. The vacuum should be adjusted in time. When the S element in the steel is high, low melting point eutectics of MoS and Fe will form, resulting in hot brittleness. Generally, Mo content When low, the impact is small.

This kind of steel is also called pre-hardened steel. that is, no heat treatment is performed after mechanical processing after quenching and tempering. The hardening and tempering temperature is 840 ~ 860 ° C, and the heat preservation coefficient is 30 ~ 45 s / mm. It should be preheated at 500 ~ 550 ° C to reduce thermal stress. The hardness after quenching the hot oil is 50 ~ 54HRC. 05 ~ 0.10μm. After tempering at 600 ℃ so that the hardness is controlled at about 30HRC for machining, the surface roughness after processing can reach Ra0. 05 ~ 0.10μm. The steel is added with S, Ca, B and other elements to become free-cutting steel. The hardness of heat treatment is controlled at 30 ~ 35HRC, which has good machinability and low surface roughness.

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2311 & P20. Is a pre-hardened plastic mold steel that is widely used in the market,and the price is very low. They are like twins,because of the similar performance of 1.2311 and P20, and the chances of their occurrence are very high.

2311&P20 is a pre-hardened plastic mold steel that is widely used in the market

2311&P20 both price are not high. They are like twins,because of the similar performance of 1.2311 and P20, and the chances of their occurrence are very high. The application is very extensive. P20 mold steel is an American standard mold steel grade, which corresponds to the Chinese brand 3cr2Mo. In theory, P20 mold steel has a certain degree of wear resistance. After Q + T processing before delivery, the hardness is between 30-35HRC. Good processing performance, mold surface can be polished, mainly used for plastic molds that do not require high mold surface finish, long-term use, plastic mold life of about 100,000 times.

2311 is a German steel brand. It is a product based on 3Cr2Mo with fine-tuned alloy composition. It reduces the wear-resistant alloy-molybdenum content and increases the hardenable alloy composition-nickel content to increase Above 100mm, the uniformity of the surface hardness and core hardness of the 2311 mold steel. Its performance is similar to that of P20, and its application is also the same as P20. China ’s 2311 and P20 mold steels have achieved batch production, which minimizes the steelmaking cost of mold steels to meet the market’s low demand. Major steel mills have almost no longer produced P20 with 3Cr2Mo composition, and more than 90% of the mill have changed to 2311 mold steel with lower alloy content, which has been produced in batches. The original dimensions are 2.2-2.3 meters in width and 6 meters in length,or above. The price is getting close to the cost of carbon steel.

2311 & P20 advantages and disadvantages

The advantages of 2311 & P20 are that the output is very large and the price is very attractive. The disadvantage is that large-scale production of molds is easy to form segregation, resulting in uneven hardness, poor cutting performance, and hard drilling.

If you got a fake 1.2738, that’s because you got P20H actually.

Now some factories make the hardness of P20 higher ,it was named P20H. Some people pretend that P20H as 728H or OT718H,I know it will make some factories angry about this news，I just tell the truth. P20H is used for plastic molds, casing molds, Shell structural parts molds, large plastics for car seats, etc., some are also used for some precision plastic mold mold bases, cold die-cast mold bases, or mechanical parts that require wear resistance.

Ms Sharon Wan

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From the chemical composition and structural characteristics of H13 steel for aluminum extrusion.

H13 steel for aluminum extrusion of process control measures

From the chemical composition and structural characteristics of H13 steel for aluminum extrusion, it can be seen that the hot working process has a great impact on the structure and performance of H13 steel for aluminum extrusion molds. In order to prevent early failure of H13 steel molds, extend the service life and improve economic benefits, a scientific and reasonable Thermal processing technology.

1. Forging process

H13 steel for aluminum extrusion has high alloy element content, poor thermal conductivity, relatively low eutectic temperature, and is prone to cause overburning. For billets with a diameter larger than Ø70mm, it should be preheated in the range of 800 ～ 900 ℃, then heated at the initial forging temperature of 1065 ～ 1175 ℃. During the forging, the drawing and upsetting are performed multiple times. The total forging ratio is greater than 4.

2. Spheroidizing annealing process

The purpose of the spheroidizing annealing process is to homogenize the structure, reduce the hardness, improve the cutting performance, and prepare the structure for quenching and tempering. The spheroidizing annealing process is held at 845 ～ 900 ℃ (1h + 1min) / mm, and then furnace cooled to 720 ～ 740 ℃ isothermal (2h + 1min) / mm. Finally, the furnace is cooled to 500 ℃ and air-cooled. Granular pearlite, hardness is less than 229HBS. The spheroidization quality can be evaluated according to the first level diagram of GB / T1299-2000 standard.

3. Quenching and tempering process

The best heat treatment process of H13 steel for aluminum extrusion is oil-quenched or classified quenching after heating at 1020 ～ 1080 ℃, and then two tempering at 560 ～ 600 ℃. The microstructure is tempered tonite + tempered sorbite + residual carbide , Micro hardness is 48 ～ 52HRC. For molds (die-casting molds) that require high rigidity, the upper limit of the heating temperature can be used for quenching. For molds that require toughness (hot forging dies), the lower limit heating temperature can be used for quenching.

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H13 steel mold should be fully preheated before work. When the preheating temperature is too high

H13 steel mold use and maintenance

Preheating of the H13 steel mold

HI3 steel has a high content of alloying elements and poor thermal conductivity, so the H13 steel mold should be fully preheated before work. When the preheating temperature is too high, the temperature of the mold is high during use, the strength is reduced, and plastic deformation is easy to occur, which causes the mold surface to collapse; when the preheating temperature is too low, the mold surface starts to use, the instantaneous surface temperature changes, thermal stress is large, and Initiation of cracks. After comprehensive consideration, the preheating temperature of the H13 steel mold is determined to be 250-300 ° C, which can reduce the temperature difference between the mold and the forging to avoid excessive thermal stress on the mold surface, and effectively reduce plastic deformation on the mold surface.

Cooling and lubrication of H13 steel mold

In order to reduce the heat load of the mold and avoid the mold temperature being too high, it is usually forced to cool during the intermittent work of the mold, which will cause the mold to periodically heat up, and the cooling effect will cause thermal fatigue cracks. Therefore, the mold should be slowly cooled after use, otherwise thermal stress will occur, which will cause the mold to crack and fail. H13 steel molds can be lubricated with water-based graphite with a graphite content of 12% to reduce the forming force and ensure the normal flow of metal in the cavity and the smooth release of the forgings. In addition, the graphite lubricant also has a cooling effect and can reduce H13 Working temperature of the steel mold.

Ms Sharon Wan

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The manufacture of H13 hot work die steel molds has to go through a series of process links such as design

The manufacture of H13 hot work die steel molds has to go through a series of process links such as design, material selection, forging, annealing, machining and heat treatment. Improper process design or process operation in each process link will cause premature failure of the mold and reduce the service life of the mold. Hot work die steel often appears in the form of failure such as chipping, collapse, wear and cracking. The form, degree and location of failure of hot work die steel record the design, material selection, forging, annealing, machining and heat treatment to a series of process links. Important information.

Observe and analyze the macroscopic morphology, microstructure and failure form of the H13 hot work die steel mold at the failure location, and use theories and methods of metallography, material physics, and fracture mechanics to suggest the macromorphological features and materials at the H13 steel mold failure location The relationship between microstructure and failure form and mold design, material selection and processing technology, so as to propose scientific and reasonable process improvement measures.

(1) Analysis of chemical composition and metallurgical quality of raw materials

Improving the cleanliness of H13 hot work die steel, especially reducing the sulfur content is an effective measure to improve the life of H13 steel molds. The sulfur content of high-quality H13 steel is between 0.005 and 0.008%. H13 steel is a hypereutectoid steel with a relatively high alloy element content. Carbide segregation occurs during smelting and casting. The ingots form coarse carbide segregation zones after forging and rolling. Carbide segregation zone and casting residual dendrites, shrinkage, porosity and inclusion directly affect the microstructure and properties of H13 steel mold, which is one of the important reasons for the early failure of the mold. The analysis of the chemical composition and metallurgical quality of the raw materials can assess whether the raw materials are qualified, which can be used to guide the formulation of scientific and reasonable forging processes and heat treatment processes.

Test method

Sampling raw materials of H13 hot work die steel, analyzing its chemical composition, and assessing whether the chemical composition meets the requirements; cutting the sample from the center of the steel, grinding and polishing, etching with 4% nitric acid alcohol solution, inspecting it on an optical microscope Microstructure, grade of carbide segregation zone and inclusion grade according to relevant national technical standards.

(2) Analysis of mold microstructure

Microstructure analysis can determine whether there is carbide segregation zone in the mold failure location, large non-metallic inclusions, network carbides, eutectic carbides and tempered martensite; micro-area composition analysis can determine the chemical composition of the mold failure location Distribution characteristics; microhardness analysis can determine the mechanical properties of the mold failure location. Comprehensively analyze the microstructure, micro-hardness and micro-area composition at the failure location of the mold, reveal the macroscopic morphological features and the micro-mechanism of the failure form at the failure location of the mold, and correctly evaluate the current forging, spheroidizing annealing, quenching and tempering Technology, so as to propose scientific and reasonable process improvement measures.

Test method: Cut the sample from the failure position of the mold, grind and polish it, etch it with 4% nitric acid alcohol solution, inspect the microstructure on an optical microscope or scanning electron microscope, measure the hardness on a microhardness tester, Microdomain composition was determined on a spectrum analyzer.

Ms Sharon Wan

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Let’s continue with the last article of the High alloy H13 steel manufacturing technique，EDM&H13 Heat treatment process.

Let’s continue with the last article of the High alloy H13 steel processing technique，EDM&H13 Heat treatment process.

(4) EDM

EDM is an indispensable finishing method in the modern mold manufacturing process. During spark discharge, the local instantaneous temperature is over 1000 ° C, which melts and vaporizes the metal at the discharge. On the surface of the EDM process, there is a thin layer of molten and re-solidified metal with many microcracks. Under the microscope, this thin layer of metal has a bright white color, that is, a bright white layer. Studies have shown that, for high alloy H13 steel, the microstructure of the surface bright layer formed by EDM is primary martensite, residual austenite, and eutectic carbide, and there is a large amount of untempered primary martensite. Micro cracks. When the

high alloy H13 steel  mold is subjected to a load during work, these microcracks can easily develop into macrocracks, which results in the mold being prone to early fracture and early wear.high alloy H13 steel molds should be tempered again after EDM to eliminate internal stress, but the tempering temperature should not exceed the highest tempering temperature before EDM.

(5) Heat treatment process

Reasonable heat treatment process can make the mold obtain the required mechanical properties and improve the service life of the mold. However, if heat treatment defects occur due to improper design or operation of the heat treatment process, the bearing capacity of the mold will be seriously endangered, causing early failure and shortening the working life. Heat treatment defects include overheating, overburning, decarburization, cracking, uneven hardened layer and insufficient hardness. After the highly alloy H13 steel mold has been in service for a certain period of time, when the accumulated internal stress reaches a dangerous limit, the mold should be destressed and tempered, otherwise the mold will crack due to internal stress when it continues to serve.

Ms Sharon Wan

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Have you ever buy the ASTM A681 tool steel?

Tool steel is commonly used steel, maybe you know a lot about it. Over the years, metallurgists have tweaked alloy steel formulas to meet specific needs or working conditions. As a result, dozens of tool steel types exist.h13、o1、o2、d2、d3, etc. Have you ever buy the ASTM A681 tool steel? I would like to talk about the s7 tool steel, you can buy it if it is available for your demand.

OTAI SPECIAL STEEL is ASTM A681 tool steel stockholders and suppliers from china. more 16 years experience in A681 tool steel round bar, flat bar, and plate supply.

ASTM A681 tool steel properties

ASTM A681 tool steel is a versatile formulation suitable for both cold and hot work. with excellent toughness, high strength and medium wear resistance. Due to its maximum shock resistance and high compression strength, it has good deformation resistance and retains good toughness during use. this grade can be machine easily in the annealed condition and it can be heat treated. When quenched in the air this material exhibits minimal distortion on hardening.

ASTM A681 applies to molds that require high hardness. It features excellent impact and shock resistance and decent resistance to softening at high temperatures. A681 is comparatively less resistant to wear but is very tough. It resists distortion during heat treatment well.

ASTM A681 tool steel round bar and flat sections can be cut to your required sizes. A681 tool steel ground bar can also be supplied, providing a high-quality tool steel precision ground tool steel bar to your required tolerances. A681 steel is also available as Ground Flat Stock / Gauge Plate, in standard and nonstandard sizes.

Application of ASTM A681 tool steel

ASTM A681 tool steel properties make it a preferred type for riveting, notching, blanking cold forming and bending dies; bull riveters, concrete breakers, dowels, drill plates, and hubs.

Mr Jack Tan

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H13 STEEL APPLICATION IN LIFE-Chapter 12

Compared to the conventional cast or wrought material, the LC H13 tool steel demonstrated excellent tensile properties. From the Refs. [24–26], the yield and tensile strengths of the annealed cast or wrought H13 were about 370–510 and 670 MPa, respectively, while the yield and tensile strengths of the wrought H13 in hardened condition were in the range of 1290–1570 and 1500–1960 MPa, respectively. The tensile and yield strengths of the as-consolidated H13 were substantially higher than the annealed cast or wrought H13, and comparable to the hardened wrought H13. The elastic modulus of the as-consolidated H13 was about the same as the wrought material. However, the elongation of the as-consolidated H13 material was about 5%–6%, which was lower than the hardened wrought H13. A post heat treatment might be used to improve the elongation of the LC H13 material if required.

The LC H13 showed very good wear resistance. The pin-on-disk wear test results indicated that, under the given test conditions (3.175 mm diameter Cr steel ball of Rc.63; 250 g test load; total 4000 m sliding distance), as-consolidated H13 specimens showed significantly improved wear resistance as compared to hardened wrought H13 specimens. For example, the average volume loss of the as-consolidated H13 specimens was about 0.14 mm³, which was only about 1/3 of the volume loss of the hardened H13 tempered at 482°C (0.4 mm³) and about one order of magnitude less as compared to the annealed wrought H13 material (1.45 mm³). In addition, the average wear volume loss of Cr steel balls tested against the LC H13 specimens (0.21 mm³) was also significantly less (only 1/3 to 1/4) than that of the balls tested against the hardened or annealed wrought H13 specimens (0.56–0.88 mm³).

Microstructures in interface region and strengths of friction stir lap Al-to-Steel and Al-to-Ti welds

Experimental procedures

FSLW experiments were conducted using a converted milling machine. As indicated in Fig. 1, the top plate was an Al alloy and 6 mm thick AA6060-T5 alloy was used. The bottom plate was either 2 mm thick mild steel or 2.5 mm thick Ti-6Al-4 V alloy. The use of a sufficiently thick top plate was to prevent fracturing in the heat affect zone and to instead cause fracture along the interface region during mechanical testing. Before each experiment, the steel or the Ti plate was wire brushed to remove the surface oxide. FS tools were made using heat treated tool steel (H13). The diameter of the shoulder was 25 mm and the threaded pin outside diameter was 6 mm. Tool tilt angle was 2.5°, ω = 1,400 rpm, and v = 20 and 80 mm/min. A LowStir^TM unit was used and mounted in the milling machine for monitoring F_z.

Fig. 2 illustrates an experiment where F_z was also used to further assist D_p setting. Higher and instable F_z values should represent D_p > 0 and low and stable values represent D_p ≤ 0. Samples were taken from the weld with sampling regions also shown in the figure. Corresponding to Region 1, during the experiment, the tool started to be lowered very slowly and slightly. The recorded steadily increasing F_z values have ascertained that the pin just touched the bottom plate but D_p should be close to zero. On the other hand, in Region 2, the tool was lowered quickly and repeatedly. Thus, in this region, D_p should mostly be larger than zero although D_p may actually vary.

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H13 STEEL APPLICATION IN LIFE-Chapter 10

Laser-aided direct metal deposition of metals and alloys 

1.5.3.3 Composition sensor

During DMD, a plasma plume is generally a by-product because of the laser-induced plasma. Therefore, real-time spectroscopic analysis can be used to predict composition by evaluating the generated plasma using optical emission spectroscopy; further, a full spatial compositional evaluation of the manufactured products can be obtained. During DMD of an H13 tool steel material, both chromium and iron atomic emission lines are observed. When comparing the H13 tool steel spectral lines with the emission lines of pure chromium and pure iron, the chromium and iron lines are easily identified. Fig. 1.22(a) shows the calibration curves using two different chromium neutral atomic lines and two iron neutral atomic lines [93]. Second-order polynomial fittings were used to form the calibration curves. By measuring the plasma line intensity ratios and comparing them with the calibration curve, the composition ratio of different elements can be obtained. To improve the prediction accuracy, an average of seven predictions using seven different calibration curves were used (Fig. 1.22(b)).

Numerical modeling methodologies for friction stir welding process

5.6.1 Geometric modeling and material model

In ABAQUS all parts are created in the part module. Workpiece is defined as a three-dimensional Eulerian body with a dimension of 110 mm × 114 mm × 4.1 mm. The thickness of the workpiece (4.1 mm) is partitioned into two parts to define void surface and material assignment region each having thickness of 1 mm and 3.1 mm, respectively. Void region is required to simulate the flash formation. Tool is modeled as a solid homogenous rigid body with a shoulder diameter of 16 mm and a cylindrical pin with a diameter of 5 mm, and a pin height of 2.5 mm pin. Tool is tilted by 2 degrees toward the trailing edge during the assembly of the parts. AA 6061 is defined as the workpiece material and tool steel H13 is defined as the tool. Physical properties of the material are defined as a function of temperature and are same as presented in Table 5.12. Physical properties of H13 tool steel are mentioned in Table 5.9. Johnson–Cook material model is defined as expressed in Eq. (5.1). Material constant for JC model is presented in Table 5.13.

In CEL analysis if no material property is assigned to a region, it is then considered as void or empty region. Therefore to incorporate the material model and physical properties of the material, material assignment tool is used as shown in Fig. 5.18. The upper part (red color) having a thickness of 1 mm acts like a void region and the lower part (blue color) is the region with assigned material properties. It is mandatory to define a void region or else simulation will not converge because during plunging stage the tool pin will impinge on the workpiece and occupy the volume inside the Eulerian body (material assigned region). Hence, material beneath the pin will flow in upward direction and occupy space in the void region (ABAQUS 6.14 documentation, 2015).

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A2 Steel Plate Any Thickness For Forging Dies And Knives provided by OTAI Special Steel . After coronavirus , all the mill factory have resume production already . In Chinese steel market , all the steel stocklist were sufficiently to provide to all over the world . A2 steel plate All the size from 3-5mm for knives to 200MM for Forging Dies , even the very special big thickness could be customed . Any new inquiry please contact with us directly . We are back to working and will work hard in this year .

A2 Steel Plate Any Thickness For Forging Dies and Knives . OTAI SPECIAL STEEL is A2 tool steel stockholders and suppliers from china . more 16 years experience in AISI A2 tool steel round bar, flat bar and plate supply.

AISI A2 Steel is a high quality Cold work tool steel, It belong to the high quality high carbon alloy tool steel. Oil Quenched & Tempered Hardenss is 28-34 HRc. AISI A2 steel Annealing delivery hardenss less than 250HB. AISI A2 steel equivalent with GB Cr5Mo1V, JIS SKD12 Steel.

A2 tool steel properties as below:

Related Specifications ASTM A29/A29M DIN EN 10083/3 JIS G4053 GB/T 3077

Chemical composition

Mechanical Properties

The mechanical properties of A2 tool steels are outlined in the following table.

Applications

A2 steels are mainly used for slitters, die shapes.

A2 tool steel typical applications include cold forging dies, coining dies, cold heading dies, shear blades, knurling tools and as cutting knives for paper, wood, fibre and resin-bonded aterial, etc.

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