Nowadays, the demand for environmental protection is higher and higher. China has taken environmental protection as a basic national policy, and began to promote cleaner production, requiring the implementation of green heat treatment, production of clean products. Implementation of green heat treatment, the most fundamental is for the sustainable development of mankind. We should make rational use of natural resources, and protect natural resources and protect the environment. For an enterprise, the relationship between development and resources, development and environment should be well dealt with in order to deal with the relationship between development and efficiency, development and innovation.
The traditional carburizing heat treatment will produce large environmental pollution, mainly in the production process of waste gas, waste water, waste residue, noise and consumption of large amounts of combustible gas and chemical raw materials. At the same time, the processing cycle of carburizing heat treatment, large deformation, difficult to achieve accurate local carburizing, these are greatly restricted the upgrading and development of technology of heat treatment of metal parts and equipment manufacturing industry of our country technology.
Induction heating quenching due to the heating speed is less, non oxidation heating, and induction heating quenching can accurately control the parts requiring heat treatment area and corresponding technical indicators, short processing cycle, adapt to the wide range of parts and quenching deformation etc.. According to statistics the sensor heat treatment cycle compared to the traditional process of carburizing process of processed products is reduced by 90%; heat treatment distortion; heat treatment energy utilization rate increased to 80%; heat treatment effect on the environment is reduced to zero; heat treatment cost is reduced by 75%; has high productivity and profit rate of return; the working environment clean, comfortable and safe today, our induction heat treatment equipment is automated, integrated, flexible and intelligent direction, gradually replace the traditional carburizing heat treatment process.
Parts and components successfully replaced by carburizing process
The material of carburized workpiece is generally low carbon steel or low carbon alloy steel (containing carbon content less than 0.25%). The chemical composition of carburized steel surface to high carbon steel, carburizing technology is widely used in mechanical parts of the aircraft, automobile and engineering machinery, such as gear, shaft, cam shaft, ball and so on, at present our company induction heat processing equipment has been successfully applied to the crankshaft, camshaft, gear and shaft parts parts and CVJ induction quenching field, completely replace the carburizing process of these parts.
Induction heat treatment equipment needs to be improved
Digital heating power advanced, reliable control, accurate measurement sensor, complete engineering system can realize the precision control (including instrumentation, valve, pump, action components, computer, software design and so on) is to ensure that the induction heat treatment equipment to produce accurate, stable and reliable quality assurance.
For example, the processing of induction heat induction heat treatment equipment to make it fast, high energy density energy applied to complex workpiece surface with similar gear as possible, which will greatly save energy and reduce the amount of deformation so as to reduce the machining allowance of the next step. At the same time will be based entirely on the heat treatment system customization, can put it in the whole production line is used as a heat treatment unit, so as to form a complete production chain, and become one of the production line, in order to adapt to the requirements of the integrated management of cost saving, saving time and energy and improve the efficiency.
Corresponding process substitution cases
(1) used on the car steering knuckle (three column shell) parts, the traditional way is to use the whole process of carburizing improve the surface hardness and mechanical properties of components, single product carburizing time over 15h, greatly restricted the auto parts manufacturers of the production efficiency, in constant velocity joint induction quenching equipment. has successfully replaced the carburizing process of the parts, single heat treatment time only need 35S (continuous scanning quenching), a quenching time of less than 3S, and 80% in the carburizing heat treatment energy saving, quality after quenching has reached the advanced level of similar foreign products.
(2) the gear tooth parts quenching, all traditional carburizing carburizing time, longer unit (more generally up to 24h), and the large deformation of gear, high rejection rate, in 2007 our company successfully developed the first domestic 1600mm whole tooth induction quenching equipment, realize the whole tooth induction heat treatment unit the processing time is only 5min, can adapt to multiple specifications of parts heat treatment, significant cost savings for the manufacturers, create considerable economic benefits.
(3) the internal gear ring of the bulldozer is hardened by carburizing and quenching. The original process of the inner gear ring is carburizing and quenching, and the shrinkage of the inner ring gear is large, resulting in a high reject rate of the workpiece.
The material of inner gear ring is 20CrMnTi, the depth of hardened layer is 1.8 ~ 2.4mm, and the surface hardness is 58 ~ 63HRC. The main process of the inner gear ring for blanking, forging, normalizing, coarse to fine car, gear shaper, carburizing, quenching, blasting, finishing and tempering; with our 1200kW power transistor and the inner hole of a quenching inductor inductor to achieve quenching process by rapid induction heating process, the workpiece rapid spray cooling, reduce the deformation of the ring gear. Only heating on the tooth surface, the other position can still maintain good plasticity, and the heating time is very short (about 40s), greatly reduce the deformation process; modified blanking, forging, normalizing, roughing, conditioning, blasting, finishing, slotting, induction quenching, tempering.
Results: induction quenching ring gear reached to formulate heat treatment requirements, processing and carburization workpiece surface hardness compared to slightly lower, but the depth of the hardened layer depth, grain size and martensite in the same level, but not with high wear resistance of carbide. After installation verification, the main engine is disassembled after 3000h, the inner gear ring wear is very small, without any problems, fully meet the requirements. 20CrMnTi material inner ring gear after carburizing high temperature tempering, and two heating quenching after low temperature tempering time is 46h, 45 steel material inner gear ring quenching and tempering, and induction hardening after low temperature tempering only 9.5h. The induction hardening process greatly shortens the manufacturing cycle and improves the production efficiency. The production cost of 20CrMnTi steel 45 steel price is high, the production cost can be reduced by 45 steel; carburizing heat treatment consumes a lot of electricity, penetrating agent, the production cost is high, and the exhaust gas pollution; induction heat treatment consumes only a small amount of energy, no emissions, no pollution, environmental protection technology. Is a new energy-saving emission reduction technology, focus on the promotion of the heat treatment industry.
Four points need to be considered in induction heat treatment instead of carburizing parts
(1) learning exchanges and technical cooperation, promote the application of induction heat treatment on heat treatment of metal parts and the cognition field, especially in the special industry needs of manufacturing enterprises and induction heat treatment manufacturer for good cooperation, carburizing and quenching process to improve the traditional and alternative carburizing equipment with induction heat treatment equipment, reduce energy consumption and the pollution of the environment.
(2) limit process, there are many enterprises have made clear regulations on the process of heat treatment, can only take the carburizing process, which greatly restricts the pace of induction heat treatment equipment to replace the carburizing process.
(3) technical and financial support, induction heat treatment equipment is a complicated system engineering, especially in high heat treatment process requirements of the field, high-end technical talent and the lack of funds is the restricting factors of induction heat treatment equipment to the development of high-end, intelligent direction. It is necessary for the state to increase efforts in capital investment, personnel training and introduction to accelerate the process of induction hardening instead of traditional carburizing and quenching process.
(4) users need to explore the application of induction hardening technology in traditional carburizing process, gradually or partially replace the traditional process. At the same time, it is hoped that the domestic iron and steel enterprises will develop new materials for induction hardening instead of carburizing and quenching.
Energy conservation, conservation of resources and the environment are our eternal goals. The intelligent and integration of induction heat treatment equipment is the direction of our efforts. “Green, energy saving, environmental protection” for the manufacturing industry, not only responsibility, but also the efforts of all of us, and reduce energy consumption is the development of heat treatment industry and improve the competitive advantage of win-win means.
Equipped with intelligent induction heat treatment SIMUWU R & D and manufacturing, to market and replace part of the carburizing heat treatment process, through the company’s recent development and application of new technology will be better able to save energy and protect our ecological environment, truly realize the “green production”, to create more value for users.