Die steel mold steel is used to make Die, die forging mold, such as mold steel. Mold material is the material and technical base mold manufacturing, which is the traditional mold steel mold material, the species, size, quality performance for mold manufacturing cycle life and plays a decisive role. In recent years, domestic and foreign steel mold production, production techniques, technology and equipment, quality, variety, etc. have achieved relatively rapid development, China has emerged Fushun Special Steel, Great Wall Special Steel, Xingcheng Special Steel, Hangzhou Iron and Steel and other one Batch quality production enterprises, the development of mold steel also contributed to the development of industrial products to high-class, individualized, high value-added direction. Mold very versatile, manufacturing a wide range of mold material in the mold material was undoubtedly the most widely used steel mold. The concept of the steel mold manufacturing Die, die forging of steel mold, such as mold processing mold when used, due to the mold very versatile, working conditions vary a great variety of mold, so mold manufacturing a wide range of materials, in the mold material was undoubtedly the most widely used tool steel. From - like carbon structural steel, carbon tool steel, alloy structural steel, alloy tool steel, spring steel, high speed tool steel, heat-resistant stainless steel mold until accommodate special needs of maraging steel and high speed steel powder, powder high alloy tool steel. Die steel use can be divided into cold die steel, hot die steel and plastic molding die three categories of cold work die steel Cold work die steel mainly used in the manufacture of cold state of the workpiece press-forming die. Such as: cold punching die, cold punching die, cold drawing dies, embossing dies, cold extrusion die, screw pressing mold and powder pressing mold. Cold die steel range is very wide, from a variety of carbon tool steel, alloy tool steel, high speed tool steel to powder high speed tool steel and high-alloy tool steel powder. Cold work tool steel with a vacuum degassing refining steel, endoplasmic pure, good machinability, cutting significantly improved, good hardenability, air hardening less prone to quench cracking very excellent abrasion resistance, good toughness, available stamping die for stainless steel and high hardness of the material. Hot die hot work die steel mainly used in the manufacture of the workpiece under high temperature pressure processing mold. Such as: hot forging dies, hot extrusion dies, casting molds, hot upsetting mold. Commonly used in hot work die steel are: high alloy tool steel carbon content of added Cr, W, Mo, V and other alloying elements; the special requirements for hot work die steel, high alloy austenitic sometimes resistant mold steel . As the plastic plastic mold Many varieties of plastic products requirements differ greatly, for the manufacture of plastic mold material is also proposed a variety of different performance requirements. Therefore, many industrialized countries have formed a wide range of plastic mold steel series. Including carbon steel, carburizing plastic mold steel, pre-hardened plastic mold steel, Aging hardening plastic mold steel, corrosion resistant plastic mold steels, free cutting plastic mold steel, plastic mold-hardened steel, martensite maraging steel and mirror-polished plastic mold steel. Performance strength properties (1) Hardness is the main technical indicators mold steel mold under high stress constant desire to maintain its shape and size, it must have a sufficiently high hardness. Cold work tool steel hardness at room temperature is generally maintained at about HRC60, hot work die steel according to their working conditions, generally required to maintain at HRC40 ~ 55 range. For the same kinds of steel, in a certain range of hardness, hardness and deformation resistance is proportional; but rather between the composition and organization of different kinds of steel, the plastic deformation resistance may have significant differences with the same hardness value. Thermal (2) red hardness at high temperature working die, required to maintain its organization and stability, thereby maintaining a sufficiently high hardness, this performance is called red hardness. Carbon tool steel, low-alloy tool steel is usually able to maintain this performance in the temperature range 180 ~ 250 ℃, the chromium molybdenum hot work die steel is generally in the temperature range 550 ~ 600 ℃ to maintain this performance. Red hardness of steel depends on the chemical composition and heat treatment of steel. (3) The compressive yield strength and compressive strength of the mold often subjected to high bending strength and bending role of pressure during use, thus requiring the mold material should have a certain compressive and flexural strength. In many cases, compressive and flexural test test conditions closer to the actual operating conditions of the mold (for example, the measured compressive yield strength steel mold punch work has shown more consistent deformation resistance) . Another advantage of bending test is the absolute value of the dependent variable, and can be more sensitive to reflect the difference in deformation resistance under different heat treatment and texture between different kinds of steel. Toughness in the work process, the mold bear the brunt of the load, in order to reduce the break during use, chipping and other forms of damage, mold steel requires a certain toughness. Factor the number of die steel chemical composition, grain size, purity, carbides and inclusions, morphology, size and distribution, as well as the microstructure and other heat treatment systems and heat treatment mold steel obtained are of steel a great deal of impact toughness. In particular purity and thermal processing deformation steel lateral impact toughness is more obvious. Toughness, strength and wear resistance are often contradictory. Therefore, a reasonable choice of the chemical composition of the steel and the use of reasonable refining, thermal processing and heat treatment process, so that the mold material abrasion resistance, strength and toughness to achieve the best fit. Department of toughness characteristics of the material sample table the total energy absorbed during the entire fracture in the course of a shock. But a lot of tools in different working conditions of fatigue fracture, therefore, the conventional shock fracture toughness can not fully reflect the performance of the mold steel. Small energy repeated impact fracture or multiple fractures work life and fatigue life and other tests technology is being adopted. Hot work tool steel thermal fatigue under service conditions in addition to cyclical changes in load-bearing, but also by high temperatures and periodic thermal shock effect, therefore, the evaluation of hot work die steel fracture resistance should pay attention to the material thermomechanical fatigue fracture properties. TMF is a comprehensive performance indicators, which include thermal fatigue properties, mechanical fatigue crack growth rate and fracture toughness of the three aspects. Thermal fatigue properties of the material reflects the working life prior to thermal fatigue crack initiation, and high thermal fatigue resistance of materials, thermal fatigue crack initiation of heat cycles more; mechanical fatigue crack growth rate reflects the material after thermal fatigue crack initiation, in forging crack under pressure when the internal expansion, expand the amount of each of stress cycles; fracture toughness materials reflect the existing unstable crack growth resistance to occur. High fracture toughness of the material, which is to take place as the unstable propagation of cracks, must have a sufficiently high stress intensity factor at the crack tip, that is must have a larger crack length. Under the premise of constant stress, in a mold already exists a fatigue crack, if the fracture toughness of the mold material is high, the crack deeper need, unstable growth can occur. That is, the thermal fatigue resistance determines that part of the fatigue crack initiation life before; the crack growth rate and fracture toughness, can determine when that portion of the subcritical extended life after the crack initiation. Thus, hot die as to obtain a high life expectancy, mold material should have high thermal fatigue resistance, low crack growth rates and high fracture toughness. Thermal fatigue performance indicators can be used thermal fatigue crack initiation number of thermal cycles, also can be measured by thermal cycling after a certain amount of fatigue cracks appearing and the average number of depth or length. The most important factor in the life of the wear resistance of the mold is often determine the wear resistance of the mold material. Die withstand considerable stress and friction at work requirements of the mold can retain their dimensional accuracy under intense friction. Mold wear is mainly mechanical wear, oxidation wear and melt three types of wear. In order to improve the wear resistance of tool steel, it is necessary not only to keep mold steel with high hardness, but also to ensure the composition, morphology and distribution of steel or other hardened carbide phases reasonable. For heavy load, high speed wear conditions of service of mold, requiring mold steel surface to form a thin and dense oxide film with good adhesion to maintain lubrication, reduce the production of sticky bite between the die and the workpiece, welding and other melt-worn, and reducing oxidation caused by the mold surface oxidation wear. So the mold working conditions have a greater impact on the wear of steel. Available wear simulation test methods measure the relative wear index?, As the wear level to characterize different chemical composition and microstructure state parameters. In life presents a predetermined burr height before, reflecting a variety of wear-resistant steels level; the test is performed on the basis of Cr12MoV contrast (= 1?). Occlusal bite resistance resistance resistance actually what happened, "cold welding" when. The performance is more important for the mold material. Usually at dry friction, the tool steel specimens to be tested with a material (such as austenitic steel) have a tendency bite Constant speed dual friction during the test campaign to a certain speed gradually increasing load, this time, turn torque also increases, the load is called "bite critical load ', the higher the critical load, the stronger the resistance bite marks. A performance, the annealing process of ball annealing temperature range, low annealing hardness and small fluctuation range, the ball higher. Second, the malleability of forging with lower deformation resistance, plastic, forging a wide temperature range, forging crack cold crack and a low propensity for precipitation of carbide network. Third, oxidation, anti-sensitivity when heated to high temperature oxidation decarbonization pregnant can be a good, slow decarbonization of the heating medium is not sensitive to pitting tendency is small. Fourth, the cutting of a large amount of cutting tool, low loss, low surface roughness. Fifth, after quenching hardenability get deeper hardened layer, use mild quenching medium can be hardened. Six, can be grinding wheel relatively low loss, no grinding burn limit large amount of wheel quality and cooling conditions are not sensitive, less prone to injuries mill grinding cracks. Seven, after the hardening of the hardening with a uniform and high surface hardness. Eight, quenching distortion cracking tendency of small conventional quenching volume change, shape warping, slight distortion, abnormal deformation tends to lower. Conventional quenching cracking sensitivity is low, and the shape of the workpiece quenching temperature insensitive. Cold mold (1) is divided into five groups: W group, O group, A group, D group, S group. ◆ W group is water quenched tool steel, there are 11 kinds of steel, 7 carbon tool steel, carbon content from 0.7% -1.3%. ◆ O group is oil quenching cold die steel (commonly known as oil steel), there are four kinds of steel, carbon content of 0.85% -1.55%, ◆ A group that is cold air quenching alloy tool steel, there are nine kinds of steel carbon content from 0.5% -2.25%. ◆ D group is high-carbon high-chromium cold work die steel, there are seven kinds of steel, carbon content of 0.9% -2.5%. ◆ S group, i.e., impact resistant tool steel, there are seven kinds of steel, the carbon content of 0.4% -0.6%. Cold die there for the high-speed steel (HSS group) and ultra-high-speed steel (SHSS group), cobalt-based alloy and steel bonded carbide (HA group), powdered steel and engineering ceramics (PIM group), carbon tungsten tool steel (F group), special-purpose tool steel (L group). (2) the selection of cold work die steel cold die steel main series is a high-class hard cold, mainly for applications requiring high compressive strength and wear-based die harder than HRC60-62. The requirements for impact resistance, high toughness of the mold, the hardness is less than HRC60- 62, the main part of S class and the class A and the most common quenched and tempered steel, spring steel, hot die or substrate steel. For large stamping die, stamping parts such as automotive exterior, the main use of cast iron. Or a small number of simple life with a zinc-based alloy or polymer composites. High-speed steel and super high-speed steel used in cold mold growing rapidly. Mainly a high "compressive strength / hardness" ratio. And the hardness can choose between HRC60-70. Powder tool steel has excellent wear life, not high hardness HRC60-62, use quite a bit. Carbon tool steel in life 100 000 punch or soft material stamping die is still a certain range of applications. US hot die hot work die steel divided into two categories: hot die steel, and super heat resisting alloys. Hot die due under temperature conditions, requires a material having heat resistance and thermal wear, in order to ensure the life of the mold to cool the mold, the mold will appear alternately hot and cold cracking, the thermal fatigue cracks, so the material and require anti-crack ability and thermal fatigue resistance. Press the heat resistance of the main series arrangement of material selection: low-alloy hardened tool steel (6G, 6F2,6F3) → of chromium hot work die steel (H11, H12, H13) → tungsten hot work die steel (H21, H22). Non-standard hot work die steel: for example, thermal upsetting mold Hardening type 6H4. Use H11, H12, H13 appears unable to meet the thermal wear when you can choose 6H1,6H2. When asked the main mold with hot wear, you can choose D2, D4 → M2, M4 → powder steel. Steel bonded carbide, cobalt-based alloy high temperature wear resistance is very high, but its thermal fatigue resistance (ie, resistance to fatigue crack hot and cold) is poor, can not be used in thermal shock state. The United States is the first listed plastic mold plastic molds for steel in tool steels country to P represented mainly divided into five categories. ◆ carburizing plastic mold steel: P1, P2, P3, P4, P5, P6. Such low carbon steel, mainly the United States and by early extrusion molding method, requires cold plastic, and has a high performance extrusion, molding surface after carburizing to improve the surface hardness and long service life. Core ultra-low carbon when the amount of deformation hardening can be minimized. ◆ quenched and tempered plastic mold: P20, P21. Plastic mold large amount of P20, has become the main, most use in the pre-hard state. ◆ carbon alloy tool steel for a thermosetting plastic. Steel are H13, and L2 and S7, O1 and A2 are also applied. This category is characterized by: (1) Basic belong secondary hardening magic, heat resistance 500-600oC good time. (2) high chromium, atmospheric corrosion. (3) hardenability excellent for large modules. ◆ stainless steel for corrosion resistance demanding plastic, mainly steel are 420,414L, 440,416. ◆ maraging steel is the result of the aging process to obtain high performance. There are two types of low-carbon Ni-A1 P21 aging steel; the other is 18Ni maraging steel. The latter is a carbon-free high purity, high strength, high toughness of the material used in the aerospace industry. For mechanical properties, dimensional accuracy, finish and corrosion resistance are demanding plastic mold. Use plastic mold steel: thin plastic box, production volume at less than 100,000, with P20, P21 pre-hardened state (HB250 ~ 300), when corrosive with 414L. High life of ordinary plastic, with P6 or P20, one after carburizing quenching hardness in HRC54-58; plastic pieces is not too large, can O1, S7. With 420 corrosive. Non-high-temperature thermosetting molding with P6, P20 after carburizing use. Corrosion resistance with 420. High temperature thermosetting plastic with H13 and S7 or carburizing steel P4. The high chromium good temper resistance and high temperature oxidation resistance. Plastic mold plastic mold steel sub prehardened ordinary plastic mold steel, pre-hardened plastic mold steel quality, pre-hardened plastic mold steel with high hardness, corrosion pre-hardened plastic mold steel mirror, mirror plastic mold steel corrosion plastic mold steel quality 5 categories Ratings assigned category to the United States die as a standard SPI-SPE following types of points. I. 101 class module (SPI-SPE standard beer 1,000,000 or more, long-term precision production mode) 1. require detailed structure of the mold 2. The mold base material hardness minimum 280BN. (DME # 2 steel / 4140 steel) 3. glue bits of steel in the mold must be hard to see 48 ~ 50HRC. remaining parts such as line position, press lock, layering and so should the hardware. 4. ejector plate have guide post. 5. line position needs to have a hard piece 6. If so, the upper mold and the lower mold line position to have a temperature control. 7. All transport waterway, recommended or electroless nickel-immersion 420 template made of stainless steel. This prevents rust and rubbish. 8. The need upright or slanting lock lock. II. 102 class mold. (no more than one million beer, a large number of production molds.) 1. The need for detailed structure of the mold. 2. The mold base material hardness minimum 280BHN. (DME # 2 steel / 4140 steel) 3. plastic mold steel inner-bit hard to see to the lowest 48 ~ 52HRC, the remaining useful parts should be treated the same. 4. Recommendations . with straight or diagonal lock body lock 5. The following items may or may not need to depend on the final number of production and timing recommendations offer such as the use of the following items to check whether clear:... A. ejector plate guide pin hard line position B. sheet. C. plating carrying water hole. D. plating mold cavity. III. 103 class module (less than 500,000 beer, in the amount of the production mold.) 1. need detailed structure of the mold. 2. The mold base material hardness minimum 165BHN . (DME # 1 steel / 1040 steel) 3. inner mold steel for the P20 (28 ~ 32HRC) or high hardness (36 ~ 38HRC). 4. rest requirements depending on need. IV. 104 class module (less than 10 Wan beer, a small amount of production mode) 1. Need mold structure. 2. mold base material P20 (28 ~ 32HRC) available mild steel or aluminum. (1040 steel) 3. The inner module is available as aluminum, mild steel or other approved metal. The remaining requirements depending on need. V. 105 class mold. (less than 500 beer, the first run-mode or test mode) 1. Available aluminum cast iron or epoxy or any material with enough strength to produce a minimum number of tests can process performance in the mold production costs, material costs typically account for 10% to 20%, while machining, heat treatment, assembly and administrative expenses accounted for 80%, so the impact of process performance die mold production cost and manufacturing ease One of the main factors. Workability - thermal processing performance, refers to a thermoplastic processing temperature range; - cold performance, refers to the cutting, grinding, polishing, drawing and other processing properties. Cold work die steel are mostly eutectoid steel and ledeburite, thermal processing and cold performance is not very good, it is necessary to strictly control the process parameters of thermal processing and cold, to avoid defects and waste. On the other hand, by increasing the purity of steel, to reduce the content of harmful impurities, improve the organization of state steel in order to improve the performance of thermal processing and cold steel, thereby reducing the production cost of the mold. To improve the cold properties of the mold steel, from the 1930s onward, was added to the mold steel S, Pb, Ca, Te so easy cutting element or elements of the mold resulting in graphite carbon steels, developing a variety of easy to cutting tool steel, in order to further improve their cutting and grinding performance, reduce tool abrasive consumption and reduce costs. Hardenability hardenability depends on the chemical composition and the state of the original organization before quenching steel; hardenability depends mainly on the carbon content of the steel. For most of the cold die steel, hardened resistance is often one of the main considerations. For hot work die steel and plastic mold steel, usually a larger die size, especially in the manufacture of large molds, hardenability is more important. In addition, the complex shape of the mold are prone to heat deformation, in order to reduce the quenching distortion, often using weak cooling quenching medium possible, such as air cooling, oil cooling or salt bath, in order to obtain the required hardness and hardened layer depth, on the need for better hardenability of tool steel. In order to facilitate the production of the deformation process, requiring mold steel quenching temperature range as possible to relax some, especially when the mold is heated by flame hardening, since it is difficult to accurately measure and control temperature, it requires a wider die steel quenching temperature range. Mold during the heat treatment, especially in the quenching process, to produce a volume change, shape warping, distortion, etc., in order to ensure the quality of mold, mold steel heat deformation requirements, especially for hard finishing after complex shape precision molds, hardened For heat deformation degree requirements are more stringent, we should use micro deformation of steel manufacturing. Sensitivity mold in the heating process, if oxidation and decarbonization phenomenon, will make hardness, wear performance and reduced life; therefore, the requirements of die steel oxidation, decarbonization sensitivity is good. For molybdenum containing high amounts of mold steel, due to oxidation, decarbonization sensitivity is strong, requires the use of special heat treatment, such as vacuum heat treatment, controlled atmosphere heat treatment, salt bath heat treatment. Common mold plastic mold steel MEK 4 high wear resistance and high toughness of plastic mold X13T6W (236) high abrasion resistant high mirror mold X13T6W (236H) high abrasion resistant high mirror mold hot work tool steel SMV3W die casting, extrusion die , plastic ADC 3 die casting, extrusion molding plastic mold steel 718S plastic within the mold of the plastic inner module 718H S136 S136H corrosion-resistant mirror mold resistant mirror mold OPTIMAX optical-grade stainless steel mirror mode ELMAX high wear resistance, corrosion resistance plastic mold CORRAX S336 highly corrosion-resistant plastic mold RAMAX 168 corrosion-resistant plastic cutting CALMAX 635 cold and hot work tool steel plastic mold 8407 metal casting, extrusion die cold work tool steel DF2 micro-deformation wear oil steel, cold XW42 stamping die cold extrusion molding, precision metal mold V10 high-life precision cutting die plastic mold steel P × 88 generic plastic mold, good polishing performance NAK55 high performance plastic mold, rubber mold NAK80 high polished mirror plastic mold S-STAR high degree of corrosion-resistant mirror mold S-STAR (A) high degree of corrosion-resistant mirror mold hot work tool steel DH31-SUPER metal casting, cold work tool steels YK30 extrusion die stamping die, bending die GOA cold processing, stamping die , cold extrusion forming die DC11, DC53 cold extrusion drawing die, drawing die, stamping die plastic mold steel P20HH P20LQ plastic mold plastic mold plastic mold steel LKM 638 general plastic mold, mold, lower mold LKM 2311 general plastic mold, mold, lower mold LKM 2312 general plastic mold, mold, lower mold LKM 738 general plastic mold, mold, lower mold LKM 738H general plastic mold, mold, lower mold LKM 818H high inserts LKM 2711 high hardness and high toughness large plastic mold LKM 2083 anti-acidic good polishing plastic mold LKM 2083H anti acidic general polished plastic mold plastic mold LKM 2316A highly acidic LKM 2316 highly acidic plastic mold LKM 2316ESR high degree and high demand in the polishing Acidic plastic mold hot work tool steel LKM 2344 metal casting, extrusion die LKM 2344SUPER metal casting, extrusion die cold work tool steels LKM 2510 micro-deformation wear oil steel LKM 2379 Microdistortion high wear oil steel LKM 2767 Microdistortion wear MUP oil steel plastic mold steel plastic mold plastic mold steel PORCERAX II PM-35 plastic and die-casting mold, breathable steel alloys, beryllium copper MOLDMAX MM40 need rapid cooling core, inserts copper alloy HIT75 MOD need rapid cooling core, inserts pure copper C1100P piece of copper electrical erosion of pure copper C1100P piece of copper aluminum alloy 6061-T6 / T651 blow mold, plastic mold, shoe mold, foam mold 6061-T6511 blow mold, plastic mold, shoe mold foam molding 7075-T651 alloy 7022-T651 A3 carbon steel S50C-S55C yellow card in plastic mold steel Wuyang 718 quality high-speed steel SKH-9 / SKH-51 high speed steel powder ASP-23 / ASP-60 bottom steel Steel No. 45 # steel grades Hitachi Metals Material Grade No. Hitachi Metals shares 2.1 Cr12 steel grades of steel 2.17 4CrW2Si 2.2 Cr12Mo1V1 steel (cold-steel, SKD11) 2.18 5CrW2Si steel 2.3 Cr12Mo1V steel (cold-work tool steel) 2.19 6Crw2Si steel 2.4 Cr5Mo1V steel ( cold work tool steel) is the introduction of the United States of A2 steel, in A class air quenching steel is the most widely used one 2.5 Cr6WV ??2.20 T7 steel steel steel 2.21 T8 2.6 Cr4W2MoV steel 2.22 T10 steel 2.7 6Cr4W3Mo2VNb 2.23 T11 steel steel steel 2.8 6W6Mo5Cr4V 2.24 T12 steel 2.9 7Cr7Mo3V2Si 2.25 W18Cr4V steel steel steel 2.26 W6Mo5Cr4V2 2.10 9Mn2V 2.11 9SiCr steel steel steel 2.12 9CrWMn 2.27 W12Mo3Cr4V3N 2.28 W12Cr4V4Mo steel steel steel 2.29 W6Mo5Cr4V2Al 2.13 CrWMn 2.14 Cr2 steel steel steel 2.15 7CrSiMnMoV 2.30 W9Mo3Cr4V 2.31 7Mn15Cr2Al3V2WMo steel steel steel 2.32 1Cr18Ni9Ti 2.16 Cr2Mn2SiWMoV Expand the number Daido Steel Material Grade No. Metal Sweden win hundred, Austria Bailu grades ID number of domestic high-grade steel grades 3.1 DHA1 steel 4.1 8402 5.1 W330 steel steel steel 6.1 4Cr5MoSiV1 3.2 DH21 Steel 4.2 8407 5.2 W302 steel steel steel 3.3 6.2 5CrMnMo DH31-S steel 4.3 QRO-90 steel 5.3 W303 steel before movements 3.1 6.3 5CrNiMo steel mold steel mold production technology development is the cornerstone of industrial development, manufacturing around the world in order to reduce production costs, improve product quality and production efficiency, improve material utilization, energy conservation, widely used all kinds of mold forming: process instead of the traditional cutting processes. Machinery manufacturing, electronics, light industry products and other industrial sectors, about 60% to 80% of the work-piece using molding. Quality, dimensional accuracy of many products, surface roughness, the cost of the replacement rate and product depends largely on the quality of the die, life and manufacturing cycle. As mold steel mold material is the main basis for mold manufacturing, with the rapid development of the mold industry, the various aspects of the steel mold number, quality, variety, size, performance, etc., continue to make higher and new requirements. Mold steel production at home and abroad, production techniques, technology and equipment, quality, variety, etc. have achieved relatively rapid development.