Plastics NONWOVEN EXTRUDER Thermal treatment process of material mold parts

Date:2022-7-19 Author:Sam

\u0026 nbsp; \u0026 nbsp; different varieties of steel for plastic molds, their chemical composition and mechanical properties are different, so the manufacturing process routes are different; similarly, the heat treatment process used by different types of plastic mold steel is also different. This section mainly introduces the characteristics of the manufacturing process and thermal treatment process of plastic mold. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; 1. The manufacturing process of plastic mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; 1. Low -carbon steel and low -carbon alloy steel mold \u0026 nbsp; 123]\u0026nbsp;\u0026nbsp;\u0026nbsp;例如,20,20Cr,20CrMnTi等钢的工艺路线为:下料→锻造模坯→退火→机械粗加工→冷挤压成形→再结晶退火→机械精加工→渗碳→ quench, recovery → grind and polish → assembly. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 2. High -alloy carbonal steel mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; for example, 12CRNI3A, 12CRNI4A steel craft route: Forging mold blanks → positive fire and high temperature recovery → mechanical rough processing → high temperature recovery → fine processing → carburizing → quenching, recovery → grinding and polishing → assembly. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 3. Capacity steel mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; for example, 45, 40CR and other steel process routes are: Forging mold blanks → annealing → mechanical coarse machining → quality adjustment → mechanical precision processing → repair, polishing → assembly. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 4. Carbon tool steel and alloy tool steel mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; The process route is: releasing → forging into mold blanks → ballization annealing → mechanical rough processing → dehuminating annealing → mechanical semi -precision processing → mechanical precision processing → quenching, recovery and polishing → assembly. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 5. Pre -hard steel mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; for example, 5NISICA, 3CR2MO (P20). For those who are directly used to process the base materials, the prehenting treatment has been performed due to the supply status, and it can be processed directly and polished and assembled after directly processing. For those who need to be forged into a blank material before processed, the process route is: feeding → modification → ballization annealing → planing or milling six sides → pre -hard treatment (34 ~ 42HRC) → mechanical rough processing → de -stress annealing → Mechanical fine processing → polishing → assembly. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 2. The thermal processing features of plastic molds \u0026 nbsp;

\u0026 nbsp; (1) Thermal treatment characteristics of carburizing steel plastic mold \u0026 nbsp;

123] \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 1. For plastic molds with high hardness, high abrasion resistance and high toughness, use carburizing steel to make, and use carburizing, quenching and low temperature recovery as the final heat treatment. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; 2. For the requirements of the carburizing layer, the thickness of the carburizing layer is 0.8 to 1.5mm. ~ 1.5mm, the thickness of the carburizing layer when pressing the soft plastic is 0.8 to 1.2mm. The carburizing layer is 0.7%to 1.0%. If carbon and nitrogen penetration is used, wear resistance, corrosion resistance, antioxidant, and anti -viscosity are better.
\u0026 nbsp; \u0026 nbsp; 3. The carburizing temperature is generally 900-920 ° C. Small molds with complex cavity can be penetrated at 840 to 860 ° C medium temperature carbon nitrogen. The carburizing thermal insulation time is 5 to 10h, and the specifics should be selected according to the requirements of the penetration layer. The carburizing process should be used to use a hierarchical carburizing process, that is, the high temperature stage (900-920 ° C) is mainly to quickly penetrate the carbon into the surface layer of the parts; Create a uniform and reasonable carbon concentration gradient distribution in the carburizing layer to facilitate direct quenching. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 4. The quenching process after carburizing is different according to the steel species, and the quenching can be used after carburizing; ); Medium -temperature carbon nitrogen directly quench after penetration (such as small precision molds with industrial pure iron or low -carbon steel squeezing formed forming); empty quenching after carburizing (such as large and medium -sized molds made of high -alloy carburizing steel). \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; (2) Thermal processing of hard steel plastic mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; 1. Mold The heat treatment and then refined processing can ensure the minimum deformation during heat treatment. For precision molds, the deformation should be less than 0.05%. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 2. The surface requirements of the plastic model cavity are very strict, so during the quenching heating process, it is necessary to ensure that the surface of the cavity is not oxidized, non -decarburized, but not hot, etc. Heating in the salt bath furnace in the protective atmosphere or strict dehydration should be heated. If an ordinary box resistor furnace is heated, the protective agent should be coated on the mold cavity surface. At the same time, the heating speed should be controlled. Cooling medium, control the cooling speed to avoid quenchingThe process produces deformation, cracking and scrapped. Generally, hot bath quenching is better, and pre -cold quenching can be used. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 3. After quenching, the fire should be higher than the working temperature of the mold. But at least 40-60 minutes. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; (3) Hot processing of pre -hard steel plastic mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 1. Pre -hard steel supply It generally does not require heat treatment, but sometimes it needs to be modified, and the modified mold after the forging must be performed. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; pre -hard steel pre -heat treatment usually uses ballization annealing. Improve the cutting performance of the mold or cold squeeze. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 3. Pre -hard steel pre -treatment process is simple, most of which adopt quality adjustment treatment. The temperature range of high temperature recovery can meet the various work hardness requirements of the mold. Due to good quenchability of this type of steel, oil -cooled, air -cooled or nitrate grading quench can be used during quenching.

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; (4) Thermal processing of time -effective hardening steel plastic \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; thermal treatment process of time -effective steel is divided into two. Basic procedures. First of all, solid -soluble treatment is performed, that is, heating the steel to high temperature, so that various alloy elements are dissolved into the austenite, and the quenching of the austenite is completed to obtain the martensite tissue. The second step is to perform timeliness, and use the timeliness to strengthen the mechanical properties of the final requirement. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 2. The heating of solid solution treatment is generally performed in a salt bath furnace and box furnace. The quenching uses oil and cold, and the steel types with good quenchability can also be air -cooled. If you can accurately control the final forging temperature when forging, it can be directly soluble. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 3. Time processing is best performed in a vacuum furnace. , Or use alumina powder, graphite powder, cast iron dandruff to perform timeliness under the protection conditions of boxing. The heating of the box should be appropriately extended the insulation time, otherwise it is difficult to achieve the timeliness effect.

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 3. The surface processing of plastic mold \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; Appropriate surface treatment.

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 1. Plastic chrome is the most applied surface treatment method. Chrome -plated layers have strong passivation capabilities in the atmosphere and can maintain metal luster for a long time. No chemical reactions are occurred in a variety of acidic media. The hardness of the plating is 1000HV, which has excellent abrasion resistance. The chrome layer also has high heat resistance, and its appearance and hardness still have no significant changes when heating to 500 ° C. \u0026 nbsp;

\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; 2. Nitrogen seepage has low processing temperature (generally 550-570 ° C), the mold deformation is small and the hardness of the peak layer (can reach 1000 ~ 1200HV ) The advantages are also very suitable for the surface treatment of plastic mold. Contains
Non Woven SPUNDBOND MACHINE Steel species with alloy elements such as chromium, molybdenum, aluminum, titanium, and titanium have better nitrogen seepage performance than carbon steel. Nitrogen seepage treatment can be greatly improved when used as plastic mold. Abrasion resistance. \u0026 nbsp;
\u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; \u0026 nbsp; suitable for plastic mold surface treatment methods: nitrogen carbon co -seepage, chemical nickel plating, ionic titanium plating, titanium carbonide or carbon nitrodolidation, Titanium, PVD, CVD method, duct or ultra -ductive duct.