Die at home and abroad heat treatment technology status and development trend analysis
Die die of heat treatment is to ensure that the important process, the manufacture of precision molds, dies of strength, the work life of mold, mold and other manufacturing costs have a direct impact. Since the 1980s, the international die of heat treatment technology developed rapidly the field is a vacuum heat treatment technology, mold and die technology to strengthen the surface of pre-hardening technology.
Die vacuum heat treatment technology
Vacuum heat treatment technology is developed in recent years a new type of heat treatment technology, it has the characteristics of manufacturing in the mold is urgently needed, such as heating to prevent oxidation and decarbonization, vacuum degassing or in addition to gas, to eliminate Hydrogen embrittlement, thereby enhancing materials (parts) of plastic, toughness and fatigue. Vacuum heating slow, small parts inside and outside factors such as temperature, the decision of the vacuum caused by heat treatment process, and other small parts deformation.
Die vacuum heat treatment in the main application is the cold vacuum quenching oil, gas-cooled vacuum quenching and tempering vacuum. In order to maintain the workpiece (such as mold) of the fine vacuum heating, cooling and cooling of the selection process and the development is very important, mold quenching process used mainly oil and gas-cooled cold. The heat treatment is no longer a mechanical processing of the mold face, as far as possible, quenched by vacuum temper, especially vacuum hardening of the workpiece (Die), it can improve the quality of surface and related mechanical properties, such as fatigue properties, surface brightness, Corrosion resistance, and so on.
Heat treatment process of computer simulation technology is the development and application, making molds of intelligent heat treatment possible. As mold of small quantities (or even a single), the variety of features and performance requirements of high-heat treatment and waste are not allowed in the characteristics, makes a mold of heat treatment to be intelligent. Foreign industrialized countries, such as the United States and Japan, high-pressure gas quenching in a vacuum, the development of the soon, the main target is mold.
Die surface treatment technologies
Die in addition to the work of the matrix have a high enough strength and toughness with a reasonable, the surface of the mold of the work and life is essential. Die surface treatment technology, by coating the surface, surface modification or complex processing technology to change the surface of the mold shape, chemical composition, organizational structure and stress state in order to obtain the necessary surface properties of systems engineering. Die Manufacturing in the application of the principal is more nitriding, carburizing and hardening film deposition.
As nitriding technology can be a good performance on the surface, and nitriding process and the hardening of steel mold a good coordination, while nitriding lower temperatures, nitriding after intense without cooling, the deformation of very small die, die The surface is enhanced by technology Nitriding earlier, is the most extensive application.
Die Die carburizing is to enhance the overall strength and toughness, that is, the work surface mold with high strength and wear resistance. Sclerosis film deposition technology is more mature is cvd, pvd. Die Since the 1980s, began to use film coating technology sclerosis. The current technical conditions, the hardening film deposition technology (mainly the equipment) costs higher, still only in a number of sophisticated, long-life die on the application, if the heat treatment used to establish the centres, while hardening film coating will greatly reduce the cost of More die if we adopt this technology, you can raise the overall level of China's mold manufacturing.
Die of pre-hardening technology
Since the 1970s, the international community to put forward the idea of pre-hardening, but because of stiffness and Cutting Machine Tool constraints, pre-hardening the hardness can not be used to mold the hardness, so pre-hardening technology R & D investment not. As the machine tool and improve the performance of cutting tools, dies of pre-hardening technology development faster, to the 1980s, developed countries in the international industrial plastic mould wood on the Use of pre-hardening ratio module has reached 30 percent (currently In more than 60 per cent).
China in the mold of pre-hardening technology, the late start, is small and can not meet the domestic die manufacturing requirements. Use of pre-hardening mold materials, mold manufacturing processes can be simplified shorten the mold of the manufacturing cycle and improve the manufacture precision die. It can be foreseen, with the processing and technological progress, pre-hardened mold material will be used to more types of mold.