Although the carburizing and quenching process has There is nothing comparable to this advantage in the aspects of stability, uniform distribution and quality of quenching hardening layer of the reliability, but in the actual production process has a long production cycle, heat treatment deformation, and difficult to clean, energy consumption, poor shortcomings. The carburizing and quenching process of these defects, it is precisely the advantages of induction heating quenching technology. Therefore, how to use reasonable induction heating quenching technology, is an urgent problem to be solved.
With the development of computer technology in carburizing process, the carbon atmosphere carburizing furnace to obtain the precise control, so that the stability and reliability of the hardening layer uniformity, the depth of hardening layer after carburizing and quenching, the quenching quality of guarantee. In addition to the domestic, especially heavy manufacturing industry scale introduction of CNC gear form grinding machine, heat treatment and surface strengthening method of gear and more inclined to adopt carburizing and quenching. But before induction heat treatment commonly used method, because the hardening effect is not stable, quenching cracking tendency is large, difficult to obtain the hardened layer distribution along the tooth profile, tooth strengthening effect is poor; the frequency and power of medium frequency heating power supply of poor adjustability, difficult to achieve real-time adjusting parameters of induction heating quenching. In recent years, more and less on gear. Therefore, the work committee China gears professional associations gear heat treatment in 2006 September in Taiyuan held a special gear induction hardening technology seminar, I had the honor to participate in the event. Their respective summarized induction heating quenching technology application result in gear surface strengthening and successful experience, make we saw induction heating quenching application prospect in strengthening gears. As the author for many years in the professional factory manufacturing gear engaged in technical personnel, induction heat treatment work on this, combined with some of the actual situation of the industry, on induction heating quenching technique in gear strengthening some experience on technical experience. Although the carburizing and quenching process has There is nothing comparable to this advantage in the aspects of stability, uniform distribution and quality of quenching hardening layer of the reliability, but in the actual production process has a long production cycle, heat treatment deformation, and difficult to clean, energy consumption, poor shortcomings. Big modulus main reducer, transmission of all kinds of rolling equipment with my company production of gear in a (M > 25), gear, gear shaft products, due to the presence of non carburized surface protection, although in the carburizing process of non carburized parts to be protected with waterproof paint, but the effect is not significant, the gear, gear shaft grinding before the semi finishing, finishing process difficult, increase tool consumption, resulting in machining process we have to go after carburizing increased non carburizing layer position, increase the production cycle. What is more important is the heat treatment deformation, cause tooth surface hardened layer is not well distributed in the actual processing, tooth size tolerance, decrease the precision grinding, affecting the normal use requirement. If taken to increase the allowance measures to solve these problems, we should increase the depth of carburized layer, thus prolonging carburizing cycle, at the same time, cause the carburized layer brittleness increases, affecting the quality of products. These defects carburizing and quenching process, is the advantage of induction heating quenching technology. Therefore, how to use reasonable induction heating quenching technology, is an urgent problem to be solved. According to the working practice for many years the induction heat treatment that, along with the tooth groove hardening by induction heating, can ensure the normal use of the gear parts completely solve the above problems, the premise is to solve the following problems along the tooth groove quenching process:
(1) the design and manufacture of along the tooth groove quenching inductor. (2) the quench hardened gear tooth surface protection is how to prevent the "tempering". (3) the reasonable selection of quenching cooling method. Therefore, in the analysis of 1750 rolling mill, the inner gear ring drum gear drive Guofeng 1450 rolling mill and the 1750 finishing mill site device in the coupling product enhancement, I plant to do try along the tooth groove hardening instead of carburizing and quenching process of the original hand, has achieved remarkable results. Notable is, to the development of efficient, energy saving, clean, precise direction twenty-first Century heat treatment, advocate "less pollution, less distortion, less (quality) dispersion, less waste, less oxidation decarbonization, less, less artificial, less waste" concept. China's "ten, one five" plan also explicitly put forward the friendly environment, economic development policy of energy saving type. All these indicate that, as a heat treatment technology of clean, energy saving, as long as the solution to its potential weaknesses, application of induction heating quenching technology on gear has a certain vitality. With the full frequency solid-state IGBT inverter technology becomes more mature, adjustability of frequency and power of heating power supply is solved completely, parameters of induction heating quenching can adjust and control is fully guaranteed, plus CNC quenching machine tool widely used, stability and reliability of the quenching quality, the enhancement effect of induction heating quenching will be further guarantee. Because power frequency in the range of 50 ~ 100Hz adjustable, hardened layer depth range can fully meet the requirements using the gear parts, and hardened layer depth is more than 10mm, which is now carburizing and quenching process which can not be realized. Future metallurgical rolling, ship, lifting and mining and other heavy gear, is bound to the deep development, and deep carburizing (> 5mm) at the current stage, China does not have the mature technology, mainly in the: (1) for deep carburizing steel also must study;
(2) carburizing quenching deformation of long cycle, the problem needs to be solved; (3) how to ensure the quality of boriding layer, and the induction heating quenching technology is in the possession of absolute advantage. The author thinks, the majority of workers engaged in induction heat treatment only through hard work, in view of the weakness of strengthening gears, carried out extensive and thorough research, find solutions and future, believe that the application of induction heating quenching technology on gear will have a better future.