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A general guideline for the processing of mold metal fine wire processing parts is to adapt to different materials, different shapes, and different technical requirements. It has a certain degree of plasticity and can achieve good processing by controlling the processing. effect.

According to the appearance and shape of parts, parts can be roughly divided into three types: shafts, plates and special-shaped parts. The common process of metal finishing is roughly: rough machining-heat treatment (quenching, quenching and tempering)-fine Grinding-electromachining-fitter (surface treatment)-assembly processing.

1 heat treatment of parts

In the heat treatment process of the parts, while obtaining the required hardness of the part, the internal stress of the metal finishing wire needs to control the internal stress to ensure the dimensional stability of the part during processing. Different materials have different treatment methods. With the development of the mold industry in recent years, the types of materials used have increased. In addition to Cr12, 40Cr, Cr12MoV, and hard alloys, for some convex and concave molds with high working strength and severe stress, a new material powder alloy steel can be selected. , Such as V10, ASP23, etc., such materials have high thermal stability and good organization.

For the parts made of Cr12MoV, quenching is performed after roughing. After the metal finishing wire is quenched, the workpiece has a large residual stress, which is likely to cause cracking during finishing or work. After the part is quenched, it should be tempered while hot to eliminate quenching. stress. The quenching temperature is controlled at 900-1020 ° C, then cooled to 200-220 ° C, and then air-cooled out of the furnace, followed by rapid tempering at 220 ° C. This method is called primary hardening process, which can obtain higher strength and wear resistance. The mold, which is the main failure form, works well. In production, some workpieces with many corners and complicated shapes are encountered. Tempering is not enough to eliminate the quenching stress. Before finishing, stress relief annealing or multiple aging treatments are required to fully release the stress.

For powder alloy steel parts such as V10 and APS23, metal finishing can withstand high temperature tempering. It can use secondary hardening process during quenching, quenching at 1050-1080 ℃, and then tempering at 490-520 ℃ for multiple times. , Can obtain higher impact toughness and stability, very suitable for molds with chipping as the main failure form. The cost of powder alloy steel is high, but its performance is good, and it is forming a widespread application trend.