[China Aluminum Network] The use of laser surface treatment technology can enable low-grade materials to achieve high-performance surface modification, to achieve a combination of low-cost parts manufacturing and high performance surface, with considerable economic and social benefits. Laser hardening relies on thermal conduction of the material matrix to perform self-cooling quenching without the need for cooling media and associated supporting equipment, which has low cost and no pollution to the environment. The surface hardness of laser-hardened parts is 15%-20% higher than that of conventional quenching, and the depth of hardened layer is usually 0.3-0.5mm. If a laser with higher power is used, it can reach 1mm. The laser-hardened heat affected zone is small, the quenching stress and deformation are small, the subsequent machining allowance is small, and even some workpieces can be directly used after laser processing.
The energy of the laser beam can be continuously adjusted, and there is no inertia. With the numerical control system, it is possible to locally harden parts with complex shapes and parts that are difficult to handle with other conventional methods, and it is also possible to perform different laser hardening treatments on different parts of the parts. Because of the above characteristics of laser surface treatment, it is particularly suitable for the surface of certain parts and local parts that are hard to be achieved by conventional hardening treatments (such as carburizing and carbonitriding quenching, nitriding and high-frequency induction heating quenching). Enhanced treatment, so it has unique advantages in the mold manufacturing: can replace the high-grade mold steel with low-grade mold steel or cast iron; replace the imported mold steel with domestic mold steel; can enhance the mold repair (remanufacturing engineering), reduce mold manufacturing cost. The application of laser surface hardening technology in mold manufacturing can integrate design, material selection, mold making, inspection, repair and other technologies, greatly shorten the design and manufacturing cycle, reduce production costs, and change mold manufacturing methods. Industry level. These advantages are unmatched by existing traditional technologies, whether they are technical, economic or service-oriented.
For example, the SC6350 micro-vehicle longitudinal beam front-end thick plate drawing die was previously made of Cr12MoV material and was composed of 12 inserts. Since the quenched deformation during the insert manufacturing is large, secondary processing is required because of the inserts. The influence of “seams” has caused the high cost and long cycle of the molds, and the parts are prone to “pulling and burning”, which has not been solved. The surface of the mold was laser-quenched, and the 12 blocks of the original material such as Cr12MoV were changed to ductile cast iron QT600-2 for integral casting. The mold surface was laser-strengthened to a hardness of 58-62HRC, and the mold was not deformed after quenching. Simply polish the surface and put it into use. Compared with the original manufacturing process, the use of laser processing mold, the material saving of 40% to 60%, processing time and tool costs reduced by 30%, a substantial increase in service life. In particular, it is worth noting that the technical problems of drawing a part from a thick plate to make the parts “pull and burn” are not yet a good solution at the international level. The use of a laser surface strengthening process effectively solves this technical problem and improves the The surface quality and dimensional accuracy of the stamped parts, which meet the requirements for the use of thick sheet drawing dies, make the choice of materials for mold design more extensive.
For another example, the mini-car covered stampings originally used gray cast iron HT300, hardness only 28 ~ 32HRC. When the die is used, only a few dozen or even a few pieces of the workpiece need to be punched to repair the die, which will seriously affect the processing schedule and increase the labor intensity. After the quench hardening treatment of the mold surface by the laser, the hardness can reach 58HRC or more, which greatly improves the service life of the mold. The experiment shows that after 5000 consecutive punching times, it is possible to continue stamping without “gloss”.
