Temperature extrusion die selection and use principles

Warm extrusion molding technology at home and abroad in recent years, the rapid development of a non- cutting precision plastic forming process , and complete the crystallization temperature ( steel materials 200-850 ℃) temperature range between room temperature and heated . High -temperature extrusion parts strength , rigidity, light weight, accuracy and surface roughness almost in machining. Temperature extrusion die is to ensure the quality of the important temperature extrusion process equipment , selection and use of its principles are: 1 , mold material extrusion die temperature during  Male/ Female Tee mould the operating cycle , due to the high temperature , high pressure and alternating loads , requiring mold steel should have strength, high hardness , toughness , wear resistance and red hardness and good . Specifically:
1 ) low temperature (200-400 ℃) when pressed , the selection 3Cr3Mo3W2V, W18Cr4V, W6Mo5Cr4V2 so on. 2 ) medium temperature (400-500 ℃) extrusion , the choice 4Cr5MoSiV, 4Cr5W2SiV, 5CrNiMo so on. 3 ) high temperature (500 ℃ above ) extrusion , the choice 5Cr4Mo3SiMnVAl, 6Cr4Mo3Ni2WV, 3Cr3Mo3W2V, 9Cr6W3Mo2V2.2, mold structure in the mold structure design, mold structure should be considered as much as possible in favor of the metal flow , die each part of the force uniform, fully consider cross-sectional shape of the cavity , the working parts should be smooth connection , try to avoid sharp corners , the stress concentration caused by the source slit to prevent cracking heat treatment and extrusion process . 3, the surface 2 inch pvc coupling mould  toughening treatment should be reasonable toughening treatment and surface hardening, the mold to get a good overall toughness and high surface hardness, wear resistance and mucosal performance , improve die life . If , Cr4W2Mo2V warm extrusion die technology: heat deformation normalizing (960 ℃, insulation 1.5h) + ball isothermal annealing (900 ℃, insulation 5h) + temperature quenching (1000-1050 ℃, oil quenched ) + temperature back fire (560-580 ℃, 1.5h) + SCN triple penetration process for review toughening treatment . Again 3Cr2W8V extrusion die temperature : 1100 ℃ heat insulation baked with pre-cooling 2-3min, and then placed in 50% K2NO3 +50% Na2NO3 salt bath , 390 ℃ insulation 0.5h baked cooled to room temperature isothermal quenching 560 ℃ × 2h tempering twice. 4 , friction reduction and lubrication method in direct contact with the blank mold surface , the mold surface blank or brush tapping tee electrofusion mould  invasion lubricants to reduce friction , can also improve thermal conductivity. Before dipping rough and can reduce heating oxidation and decarbonization . Production found : Graphite + boron oxide , boron oxide + molybdenum disulfide , graphite, i.e., water or oil , graphite, molybdenum disulfide + + oleic acid + alumina + silica sand and lubricants , can achieve good lubrication.