Explanation

die steel suitable for making molds for plastics products. According to the working conditions and characteristics of plastics molds, die steel for plastic materials forming is required to have a high degree of purity to obtain a high gloss machined surface, wear and corrosion resistance of the surface and a certain depth of surface hardening layer, high enough strength and toughness to ensure a long service life, and good process performance such as small heat treatment deformation to ensure dimensional accuracy. die steel for plastic materials forming (YB/T094-1997, YB/T107-1997, YB/T129-1997) mostly uses structural steel and tool steel, but there are special requirements for its surface quality, so SM is added before steel designation. die steel for plastic materials forming can be divided into: Thermoplastic extrusion moulding plastics molds, mostly medium carbon non-alloy steel SM45, SM50, etc; Small and medium-sized plastics molds with less complex shapes can be made of tool steel such as T7A, T10A, 9Mn2V, CrWMn, etc; Large plastics dies can be made of SM4Cr5M 〇 SiV] steel with high hardenability or air quenched micro deformation die steel; Large plastics molds requiring high wear resistance can be made of SMCrl2MolVl steel; The complex and precise plastics mould mostly adopts carburizing die steel for plastic materials forming such as 20, 20Cr, SMlCrNi3, etc. or pre hardened die steel for plastic materials forming such as SM3Cr2Mo, SM3Cr2NiMo, etc; For the situation that harmful gases will be released during plastics forming and cause erosion to the mold, martensitic stainless steel such as SM20O13, SM30Crl7Mo, etc. shall be used.

Classification