The surface treatment technology of mold parts is a systematic project to change the surface morphology, chemical composition, organizational structure and stress state of mold parts through surface coating, surface modification or composite treatment technology to obtain the required surface properties. The nitriding process includes gas nitriding, ion nitriding, liquid nitriding, etc. In each nitriding method, there are several nitriding technologies, which can adapt to the requirements of different steel grades and different workpieces. From the surface treatment method, it can be divided into: chemical method, physical method, physical chemical method and mechanical method.

Although new treatment technologies aimed at improving the surface properties of mold parts are constantly emerging, nitriding, carburizing and hard film deposition are the most widely used in mold parts manufacturing. Because the nitriding technology can form a surface with excellent performance, and the nitriding process has a good coordination with the quenching process of the die fitting steel, and the nitriding temperature is low, no intense cooling is required after nitriding, and the deformation of the die fitting is extremely small, so The surface strengthening of mold parts is the earliest using nitriding technology, and it is also the most widely used.

In addition to the requirement of high enough strength and toughness for mold parts, their surface properties are very important to the working performance and service life of mold parts. The improvement of these properties, relying solely on the improvement and improvement of the matrix material is very limited and uneconomical, and through surface treatment technology, you can often get twice the result with half the effort, which is the reason for the rapid development of surface treatment technology. These surface properties refer to: wear resistance, corrosion resistance, friction coefficient, fatigue properties, etc.

Surface treatment technology of mold parts

The purpose of carburizing mold parts is mainly to improve the overall strength and toughness of mold parts, that is, the working surface of mold parts has high strength and wear resistance. The technical idea introduced from this is to use lower-grade materials , that is, replacing higher-grade materials by carburizing and quenching, thereby reducing manufacturing costs. The hard film deposition technology was first applied to tools (tools, cutting tools, measuring tools, etc.), and the effect was excellent. Many tools have applied hard film as a standard process. The most mature hard film deposition technologies are CVD and PVD.

In order to increase the bonding strength of the film workpiece surface, a variety of enhanced CVD and PVD technologies have been developed. The mold parts have been using the coating hard film technology since the 1980s. Under the current technical conditions, the cost of hard film deposition technology (mainly equipment) is relatively high, and it is still only applied to some precision and long-life mold parts. If a heat treatment center is used, the cost of coating hard film will be greatly If more mold parts adopt this technology, the overall level of mold parts manufacturing in my country can be improved.