About 718 die steel, is to improve our grades 3Cr2NiMo in P20 (3Cr2Mo) steel numbers, have greatly improved the quality, make up the shortfall P20 mold steel, mold steel P20 who fail to meet the occasion. Currently appearing in China's steel mold steel market in addition to the Chinese standard steel but also have a P20 + Ni. Swedish 718,718H (ASSAB), PX5 \ PX4 (Daido Steel), GS-711, GS-738, GS-312, GS-318 (German Thyssen), Austria M238 ECOPLUS (Bluff company), CS718 (the country Changcheng Special Steel), SWP20 (Shanghai Five steel companies), etc., and therefore can not be used in addition to have corrosion resistance requirements of the plastic mold parts, the current is typical of steel most widely used general-purpose plastic mold steel. Often referred to as the "Advanced" plastic mold steel, the newly developed new kinds of steel often use it as a typical contrast. 718 steel is Sweden win hundred pre-hardened plastic mold steel mirror anti-acid. The pre-hardened steel, the material evenly. Cleanness. With excellent polishing performance and light carved sex. Also has high hardenability, good electrical properties and processing striae processing performance. No need to pre-hardened steel hardened grooves can also be used, the flange can be implemented flame hardening, the hardness can be increased to 52HRC. The steel has good machinability and wear resistance, hardness distribution uniform. Also has a good polishing performance, process is simple, affordable, and therefore a larger amount. Corresponding steel China GB standard steel 3Cr2NiMo German DIN standard material steel 1.2738 Sweden Assab ASSAB 718 US standard steel AISI / SAE standard steel P20 + Ni Japan JS standard steel SNCM optimize ISO ISO standard steel 35CrMo2 . Uses 718 and P20 mold steel use the same type of mold steel, but because of hardenability better, better performance, you can make the size of a large, high-grade plastic mold forming parts. With the development of plastic mold, there will be more and better updates appear improved mold steel, China's Baosteel I B30H is one example. Thermoplastic injection molding, extrusion die. Overload mold main part. Cold structural parts. Commonly used in the manufacture of TV cabinet, washing machine, refrigerator shells, buckets and so on. Characteristics for large long-life plastic injection mold, such as home appliances, computer casings, such as mold. High surface finish blow mold plastic mold due to the high hardness, can be used for molding plastic mold of the slider tool; depending on production needs to be applied flame hardening or nitriding treatment of mold parts. Steel Type: Pre-hardened plastic mold steel steel Features: polishing, galvanic corrosion, welding and machining of good factory state: After hardening and tempering to HB290-330 pure steel vacuum degassing refining treatment for polishing or etching grain processing plastic mold. Pre-hardened state supplied without heat treatment can be used directly in the mold, to shorten the construction period. By forging rolling processing, compact structure, 100% ultrasonic testing, non-porous, needle defects. Application Examples a) plate, high surface requirements of large household appliances mold. b) apply to the large mirror plastic mold, such as automobiles, home appliances, audio and video products. c) can be used for the required degree of mirror-polished plastic mold for PA, POM, PS, PE, PP, ABS plastic injection molding, blow molding. d) a high degree of polish and high demands of the mold cavity. Chemical composition of elements C Si Mn Mo Cr Ni standard content (%) 0.28 ~ 0.40 0.20 ~ 0.80 0.60 ~ 1.00 0.30 ~ 0.55 1.40 ~ 2.00 0.80 ~ 1.20 YB / T127-1997