Process control of precision machining of molds

The general guiding principle for the processing of non-standard parts in molds is to carry out adaptive processing for different materials, shapes, and technical requirements. It has a certain degree of plasticity and can achieve good processing results through the control of processing.
According to the different appearance and shape of the parts, they can be roughly divided into three categories: shaft type, plate type, and special-shaped parts. The common process is roughly as follows: rough machining - heat treatment (quenching, tempering) - precision grinding - electrical machining - fitter (surface treatment) - Assembly Processing.
2.1 Heat treatment of parts
The heat treatment process of parts not only ensures the required hardness of the parts, but also controls the internal stress to ensure dimensional stability 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, new materials such as powder alloy steel V10, ASP23, etc. can be selected for convex and concave molds with high working strength and severe stress. These materials have high thermal stability and good organizational state.
For parts made of Cr12MoV, quenching treatment is carried out after rough machining. After quenching, there is a large residual stress in the workpiece, which can easily lead to cracking during precision machining or work. After quenching, the parts should be tempered while hot to eliminate quenching stress. The quenching temperature is controlled at 900-1020 ℃, then cooled to 200-220 ℃ for air cooling, and then quickly returned to the furnace for tempering at 220 ℃. This method is called a one-time hardening process, which can achieve high strength and wear resistance, and has a good effect on molds with wear as the main form of failure. In production, some workpieces with many corners and complex shapes are encountered, and tempering is not enough to eliminate quenching stress. Before precision machining, stress relief annealing or multiple aging treatments need to be carried out to fully release stress.
For powder alloy steel parts such as V10 and APS23, due to their ability to withstand high temperature tempering, secondary hardening process can be used during quenching. Quenching at 1050-1080 ℃, followed by high-temperature tempering at 490-520 ℃ and multiple times, can achieve high impact toughness and stability. It is very suitable for molds with blade failure as the main form of failure. Powder alloy steel has a high cost, but its performance is good, and it is forming a trend of widespread application.
2.2 Grinding of parts
There are three main types of machine tools used for grinding: surface grinding machines, internal and external cylindrical grinding machines, and tool grinding tools. During precision machining and grinding, it is necessary to strictly control the occurrence of grinding deformation and grinding cracks. Even very small cracks will be exposed in subsequent processing and use. Therefore, the feed for precision grinding should be small, not large, the coolant should be sufficient, and parts with dimensional tolerances within 0.01mm should be ground at a constant temperature as much as possible. From the calculation, it can be seen that for a 300mm long steel piece, when the temperature difference is 3 ℃, the material is 10.8% μ Change around m, 10.8=1.2 × three × 3 (1.2 deformation per 100mm) μ M/℃), each finishing process needs to fully consider the impact of this factor.

Choose appropriate grinding sand during precision grinding

Dongguan Anding Technology Manufacturing Co., Ltd. is a modern private enterprise integrating product development and design, Precision mold manufacturing, product injection molding, oil injection screen printing, and electronic assembly. It is located in Chuangye Road, Dongshan Village, Qishi Town, Dongguan City, with convenient transportation. Our company adheres to the corporate tenet of "emphasis on quality, integrity, and responsibility", with the business philosophy of "customer first, technology, efficiency, and service". Under the guidance of the "Four Fines" business policy, the company has reached the forefront of the industry in the entire precision parts processing industry.Injection Mold Processing - TV Plastic shell mold, Electronic product mold,Electronic Digital Product Mold,Mobile Phone Peripheral Product Mold,Toy product molds, Household.