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The surface treatment technology of precision mold parts is a systematic engineering that changes the morphology, chemical composition, microstructure and stress state of the surface of precision mold parts through surface coating, surface modification or composite treatment techniques to obtain the required surface performance. Nitriding processes include gas nitriding, ion nitriding, liquid nitriding, etc. Within each nitriding method, there are several nitriding techniques that can meet the requirements of different steel grades and different workpieces. In terms of surface treatment methods, they can be further classified into: chemical methods, physical methods, physicochemical methods and mechanical methods. Although new treatment technologies aimed at improving the surface performance of precision mold parts are constantly emerging, the ones mainly applied in the manufacturing of precision mold parts are nitriding, carburizing and hardening film deposition. Due to the fact that nitriding technology can form a surface with excellent performance, and the nitriding process has good coordination with the quenching process of precision mold parts steel, as well as the low nitriding temperature and no need for intense cooling after nitriding, the deformation of precision mold parts is extremely small. Therefore, the surface strengthening of precision mold parts is the earliest to adopt nitriding technology and also the most widely used.

In addition to requiring sufficient strength and toughness, the surface performance of precision mold parts is crucial to their working performance and service life during operation. The improvement of these performances is very limited and uneconomical to rely solely on the improvement and enhancement of the base material. However, through surface treatment technology, it is often possible to achieve twice the result with half the effort. This is precisely the reason why surface treatment technology has developed rapidly. These surface properties refer to: wear resistance, corrosion resistance, coefficient of friction, fatigue performance, etc.

The purpose of carburizing precision mold parts is mainly to enhance the overall strength and toughness of the precision mold parts, that is, the working surface of the precision mold parts has high strength and wear resistance. The technical idea introduced from this is to use lower-grade materials, that is, to replace higher-grade materials through carburizing and quenching, thereby reducing manufacturing costs. The hardening film deposition technology was first applied to tools (cutting tools, cutting tools, measuring tools, etc.), with excellent results. Many types of cutting tools have adopted the coating of hardening films as a standard process. At present, the relatively mature hardened film deposition technologies are CVD and PVD. To enhance the bonding strength of the film layer on the surface of the workpiece, various enhanced CVD and PVD technologies have been developed now. Precision mold parts have adopted the coating hardening film technology since the 1980s. Under the current technological conditions, the cost of hardening film deposition technology (mainly equipment) is relatively high and it is still only applied to some precision and long-life precision mold parts. If a heat treatment center is established, the cost of coating hardening film will be greatly reduced. If more precision mold parts adopt this technology, the overall manufacturing level of precision mold parts in our country can be improved.