成人福利国产午夜av免费不卡_日本制服丝袜亚洲天堂_欧美喷水自慰精品二区_免费观看性生交大片人_中文字a∨字幕在线观看_国产东北妇女露脸_国产一级特黄a高潮片_欧美午夜乱色视频在线观看_精品一级毛片免费视频_欧美一区二区VIDEO

        Injection mold in injection molding machine manufacturing plastic products in general need to carried out under the environment of high temperature of one hundred and fifty degrees to two hundred degrees Celsius, so the selection of raw materials in the process of manufacture of injection mould will need to be very attention, it will be late for the whole life and production of injection mold plastic products quality plays an important role, so when choosing injection mold steel raw material need to meet the performance requirements?

        Sufficient surface hardness and wear resistance

        The hardness of injection mold is usually below 50-60HRC. The mold after heat treatment should have enough surface hardness to ensure that the mold has enough stiffness. Due to the filling and flow of injection molding, the mold should bear great compressive stress and friction force, which requires the mold to keep the stability of shape accuracy and dimensional accuracy, so as to ensure the mold has enough service life. The mold's wear resistance depends on the steel's chemical composition and heat treatment hardness, so strengthening the mold's hardness is conducive to enhancing its wear resistance.

        Excellent machinability

        Most injection moulds require some cutting and fitter repair in addition to EMD processing. In order to extend the service life of the cutting tool, enhance the cutting performance and reduce the surface roughness, the hardness of the steel used in the injection mold must be appropriate.

        Iii. The carbon steel of grade 50 has certain strength and wear resistance. After tempered, it is mostly used as formwork material. High carbon tool steel and low alloy tool steel have higher strength and wear resistance after heat treatment, and are used for forming parts. However, high carbon tool steel is only suitable for small size and simple shape due to its large deformation in heat treatment.

        Good thermal stability

        Plastic injection mould parts shapes are more complex, difficult to process after quenching, so should choose as far as possible with good thermal stability, after the double color molding processing by heat treatment due to the linear expansion coefficient, heat treatment deformation is small, the size of the rate of change caused by the temperature difference is small, the microstructure and mould size stability, can reduce or no longer carry on the processing, can guarantee the mold size accuracy and surface roughness requirements.

        Good polishing performance

        High - quality two - color injection molding products require small cavity surface roughness. For example, the injection mold cavity surface roughness is required to be less than the level of Ra0.1 ~ 0.25, and the optical surface is required to be Ra<0.01nm. The cavity must be polished to reduce the surface roughness. For this choice of steel materials required less impurities, microstructure uniform, no fiber orientation, polishing should not appear pitting or orange peel defects.